1X \ 7 $ 
 
 U. S. DEPARTMENT OF AGRICULTURE, 
 
 BUREAU OF ENTOMOLOGY— BULLETIN No. 78 (Revised). 
 
 L. O. HOWARD, Entomologist and Chief of Bureau. 
 
 ECONOMIC LOSS TO THE PEOPLE OF THE 
 
 UNITED STATES THROUGH INSECTS 
 
 THAT CARRY DISEASE. 
 
 BY 
 
 L. O. HOWARD, Ph. D. 
 
 Entomologist and Chief of Bureau. 
 
 Issued May 27, 1909. 
 
 WASHINGTON: 
 
 GOVKKXMKNT PRINTING OFFICE, 
 
 1909. 
 
U. S. DEPARTMENT OF AGRICULTURE, 
 
 BUREAU OF ENTOMOLOGY— BULLETIN No. 78 (Revised). 
 
 L. O. HOWARD. Entomologist and Chief of Bureau. 
 
 ECONOMIC LOSS TO THE PEOPLE OF THE 
 
 UNITED STATES THROUGH INSECTS 
 
 THAT CARRY DISEASE. 
 
 BY 
 
 L. O. HOWARD, Ph. D. 
 
 Entomologist and Chief of Bureau. 
 
 Issued May 27, 1900. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE 
 
 1909. 
 
BUREA U OF ENTOMOLOGY. 
 
 L. O. Howard, Entomologist and Chief of Bureau. 
 
 C. L. Marl att, Entomologist and Acting Chief in absence, of Chief. 
 
 R. S. Clifton, Executive Assistant. 
 
 C.J. Gilliss, Chief Clerk. 
 
 F. H. Chittenden, in charge of truck crop and special insect investigations. 
 A. D. Hopkins, in charge of forest insect investigations. 
 
 W. D. Hunter, in charge of southern field crop insect and tick investigations. 
 F. M. Webster, in charge of cereal and forage plant insect investigations. 
 A. L. Quaintance, in charge of deciduous fruit insect investigations. 
 
 E. F. Phillips, in charge of apiculture. 
 
 D. M. Rogers, in charge of gipsy moth and brovm-taU moth field work. 
 A. W. Morrill, in charge of white fly investigations. 
 W. F. Fiske, in charge of gipsy moth laboratory. 
 
 F. C. Bishopp, in charge of cattle tick life history investigations. 
 A. C. Morgan, in charge of tobacco insect investigations. 
 
 R. S. Woglum, in charge of hydrocyanic-acid gas investigations. 
 R. P. Currie, in charge of editorial work. 
 Mabel Colcord, librarian. 
 2 
 
LETTER OE TRANSMITTAL. 
 
 U. S. Department of Agriculture, 
 
 Bureau of Entomology, 
 Washington, D. C, April 20, 1909. 
 Sir : I have the honor to recommend for publication as Bulletin 78, 
 revised, of this Bureau the accompanying slightly revised copy of the 
 original edition of this bulletin, entitled " Economic Loss to the 
 People of the United States Through Insects that Carry Disease," 
 the supply of which is now almost exhausted. 
 
 The United States is just awakening to a knowledge of the disas- 
 trous results following a lack of appreciation of the danger arising 
 from the unchecked development of mosquitoes and the typhoid fly, 
 and it is hoped that this bulletin will not only emphasize this danger, 
 but will also lend support to movements, both local and widespread, 
 toward the destruction (often so easy) of these carriers of disease. 
 Respectfully, 
 
 L. O. Howard, 
 Entomologist and Chief of Bureau. 
 Hon. James Wilson, 
 
 Secretary of Agriculture. 
 

CONTENTS 
 
 Page. 
 
 Introduction 7 
 
 Mosquitoes 8 
 
 Malaria 8 
 
 Yellow fever 17 
 
 Work on the Isthmus of Panama 21 
 
 The typhoid fly, commonly known as the house fly 23 
 
 Endemic disease as affecting the progress of nations 36 
 
 Index 39 
 
 5 
 
ECONOMIC LOSS TO THE PEOPLE OF THE UNITED STATES 
 THROUGH INSECTS THAT CARRY DISEASE. 
 
 INTRODUCTION. 
 
 It has been definitely proven and is now generally accepted that 
 malaria in its different forms is disseminated among the individuals 
 of the human species by the mosquitoes of the genus Anopheles, and 
 that the malarial organism gains entrance to the human system, so 
 far as known, only by the bite of mosquitoes of this genus. It has 
 been proven with equal definiteness and has also become generally 
 accepted that yellow fever is disseminated by the bite of a mosquito 
 known as Stegomyia calopus (possibly by the bites of other mos- 
 quitoes of the same genus), and, so far as has been discovered, this 
 disease is disseminated only in this way. Further, it has been sci- 
 entifically demonstrated that the common house fly is an active agent 
 in the dissemination of typhoid fever, Asiatic cholera, and other 
 intestinal diseases by carrying the causative organisms of these dis- 
 eases from the excreta of patients to the food supply of healthy indi- 
 viduals; and that certain species of fleas are the active agents in the 
 conveyance of bubonic plague. Moreover, the tropical disease known 
 as filariasis is transmitted by a species of mosquito. Furthermore, it 
 is known that the so-called " spotted fever " of the northern Rocky 
 Mountain region is carried by a species of tick ; and it has been dem- 
 onstrated that certain blood diseases may be carried by several species 
 of biting insects. The purulent ophthalmia of the Nile basin is 
 carried by the house fly. A similar disease on the Fiji Islands is 
 conveyed by the same insect. Pink eye in the southern United States 
 is carried by minute flies of the genus Hippelates. The house fly 
 has been shown to be a minor factor in the spread of tuberculosis. 
 The bedbug has been connected with the dissemination of several dis- 
 eases. Certain biting flies carry the sleeping sickness in Africa. A 
 number of dangerous diseases of domestic animals are conveyed by 
 insects. The literature of the whole subject has grown enormously 
 during the past few years, and the economic loss to the human species 
 through these insects is tremendous. At the same time, this loss is 
 entirely unnecessary; the diseases in question can be controlled, and 
 the suppression of the conveying insects, so absolutely vital with 
 certain of these diseases and so important in the others, can be brought 
 about. 
 
8 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 MOSQUITOES. 
 
 Entirely aside from the loss occasioned by mosquitoes as carriers 
 of specific diseases, their abundance brings about a great monetary 
 loss in other ways. 
 
 Possibly the greatest of these losses ie in the reduced value of real 
 estate in mosquito-infested regions, since these insects render abso- 
 lutely uninhabitable large areas of land available for suburban homes, 
 for summer resorts, for manufacturing purposes, and for agricultural 
 pursuits. The money loss becomes most apparent in the vicinity of 
 Large centers of population. The mosquito-breeding areas in the 
 vicinity of New York City, for example, have prevented the growth 
 of paying industries of various kinds and have hindered the proper 
 development of large regions to an amount which it is difficult to 
 estimate in dollars and cents and which is almost inconceivable. The 
 same may be said for other large cities near the seacoast. and even 
 of those inland in low-lying regions. The development of the whole 
 State of Xew Jersey has been held back by the mosquito plague. 
 
 Agricultural regions have suffered from this cause. In portions of 
 the Northwestern States it has been necessary to cover the work horses 
 in the field with sheets during the day. In the Gulf region of Texas 
 at times the market value of live stock is greatly reduced by the 
 abundance of these insects. In portions of southern Xew Jersey there 
 are lands eminently adapted to the dairying industry, and the markets 
 of Xew York, Philadelphia, and the large Xew Jersey cities are at 
 hand. In these localities herds of cattle have been repeatedly estab- 
 lished, but the attacks by swarms of mosquitoes have reduced the yield 
 of milk to such an extent as to make the animals unprofitable, and 
 dairying has been abandoned for less remunerative occupations. The 
 condition of the thoroughbred race horses at the great racing center, 
 Sheepshead Bay. Long Island, was so impaired by the attacks of 
 mosquitoes as to induce those interested to spend many thousands of 
 dollars a few years ago in an effort to abate the pest. 
 
 All over the United States, for these insects, and for the house fly 
 as well, it has become necessary at great expense to screen habitations. 
 The cost of screening alone must sorely exceed ten millions of dol- 
 lars per annum. 
 
 MALARIA. 
 
 The west coast of Africa, portions of India, and many other tropi- 
 cal regions have always, at least down to the present period, been 
 practically uninhabitable by civilized man. owing to the presence 
 of pernicious malaria. The industrial and agricultural development 
 of Italy has been hindered to an incalculable degree by the prevalence 
 of malaria in the southern half of the Italian peninsula, as well as in 
 
MOSQUITOES AND MALARIA. 9 
 
 the valley of the Po and elsewhere. The introduction and spread of 
 malaria in Greece is stated by Ronald Ross, and with strong reasons, 
 to have been largely responsible for the progressive physical degen- 
 eration of one of the strongest races of the earth. 
 
 In the United States, malaria, if not endemic, was early introduced. 
 The probabilities are that it was endemic, and it is supposed that the 
 cause of the failure of the early colonies in Virginia was due to this 
 disease. It is certain that malaria retarded in a marked degree the 
 advance of civilization over the Xorth American Continent, and 
 particularly was this the case in the march of the pioneers through- 
 out the Middle TTest and throughout the Gulf States west to the Mis- 
 sissippi and beyond. In many large regions once malarious the disease 
 has lessened greatly in frequency and virulence owing to the reclama- 
 tion of swamp areas and the lessening of the number of the possible 
 breeding places of the malarial mosquitoes, but the disease is still 
 enormously prevalent, particularly so in the southern United States. 
 There are many communities and many regions in the Xorth where 
 malaria is unknown, but in many of these localities and throughout 
 many of these regions Anopheles mosquitoes breed, and the absence 
 of malaria means simply that malarial patients have not entered these 
 regions at the proper time pf the year to produce a spread of the 
 malady. It has happened again and again that in communities where 
 malaria was previously unknown it has suddenly made its appearance 
 and spread in a startling manner. These cases are to be explained, 
 as happened in Brookline, Mass., by the introduction of Italian labor- 
 ers, some of whom were malarious, to work upon the reservoir; or, 
 as happened at a fashionable summer resort near Xew York City, by 
 the appearance of a coachman who had had malaria elsewhere and 
 had relapsed at this place. In such ways, with a rapidly increasing 
 population, malaria is still spreading in this country. 
 
 To attempt an estimate of the economic loss from the prevalence 
 of malaria in the United States is to attempt a most difficult task. 
 Prof. Irving Fisher, in one of his papers before the recent Inter- 
 national Tuberculosis Congress, declared that tuberculosis costs the 
 people of the United States more than a billion dollars each year. 
 In this estimate Professor Fisher considered the death rate for con- 
 sumption, the loss of the earning capacity of the patients, the period 
 of invalidism, and the amount of money expended in the care of the 
 sick, together with other factors. In making these estimates he had 
 a much more definite basis than can be gained for malaria. The 
 death rate from malaria (as malaria) is comparatively small and is 
 apparently decreasing. Exact figures for the whole country are not 
 available. From a table comprising 22 cities it appears that two- 
 thirds of the deaths from malaria in the United States occur in the 
 South — one-third only in the Xorth. The death rate from malaria 
 83434— Bull. 78—09 2 
 
10 
 
 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 by States is available only for the following registration States: 
 California. Colorado, Connecticut, District of Columbia. Indiana, 
 Maine. Maryland. Massachusetts, Michigan, New Hampshire. Xew 
 Jersey, Xew York, Pennsylvania, Rhode Island, South Dakota, and 
 Vermont, all of which are Northern States. For these States the 
 census reports from 1900 to 1907, inclusive, give the following death 
 rates: 
 
 Table I. — Deaths <iu> to malaria in th< registration states, 1900-1907. 
 
 Year. 
 
 Number 
 of deaths 
 from ma- 
 laria per 
 100.000 
 popula- 
 tion. 
 
 Total 
 deaths 
 from ma- 
 laria. 
 
 Year. 
 
 Number 
 of deaths 
 from ma- 
 laria per 
 100,000 
 popula- 
 tion. 
 
 Total 
 deaths 
 from ma- 
 laria. 
 
 1900 
 
 7.9 
 6.3 
 5.4 
 4.3 
 4.2 
 
 2,434 
 1,791 
 1,738 
 1,410 
 1.391 
 
 1905 3.9 
 
 1906 3.5 
 
 1907 
 
 1,321 
 
 1901 
 
 1.415 
 
 1902 
 
 1 166 
 
 1903 
 
 
 
 
 1904... 
 
 
 12 666 
 
 
 
 
 Estimating, from the preceding table, the average annual death 
 rate due to malaria at 4.8 per 100.000 population, and considering 
 that the registration area includes only 16 of the Northern States 
 (assuming fairly, however, that the death rate in the other Northern 
 States is the same), it seems reasonably safe to conclude that the death 
 rate from malaria for the whole United States must surely amount 
 to 15 per 100,000. It is probably greater than this, since the statistics 
 from the South are city statistics, and malaria is really a country 
 disease. Thus it is undoubtedly safe to assume that the death rate 
 for the whole population of the United States is in the neighborhood 
 of 15 per 100.000. This would give an annual death rate from 
 malaria of nearly 12.000 and a total number of deaths for the 8-year 
 period 1900-1907 of approximately 96,000. 
 
 But with malaria perhaps as with no other disease does the death 
 rate fail to indicate the real loss from the economic point of view. A 
 man may suffer from malaria throughout the greater part of his life, 
 and his productive capacity may be reduced from 50 to 75 per cent, 
 and yet ultimately he may die from some entirely different immediate 
 cause. In fact, the predisposition to death from other causes brought 
 about by malaria is so marked that if. in the collection of vital statis- 
 tics, it were possible to ascribe the real influence upon mortality that 
 malaria possesses, this disease would have a very high rank in mor- 
 tality tables. Writing of tropical countries, Sir Patrick Manson 
 declares that malaria causes more deaths, and more predisposition to 
 death by inducing cachectic states predisposing to other affections, 
 than all the other parasites affecting mankind together. Moreover, 
 it has been shown that the average life of the worker in malarious 
 
MOSQUITOES AND MALARIA. 11 
 
 places is shorter and the infant mortality higher than in healthy 
 places. 
 
 But, aside from this vitally important aspect of the subject, the 
 effect of malaria in lessening or destroying the productive capacity 
 of the individual is obviously of the utmost importance, and upon the 
 population of a malarious region is enormous, even under modern 
 conditions and in the United States. It has been suggested that the 
 depopulation of the once thickly settled Roman Campagna was due to 
 the sudden introduction of malaria by the mercenaries of Scylla and 
 Marius. Celli, in 1900, states that owing to malaria about 5,000,000 
 acres of land in Italy remain — not uncultivated, but certainly very 
 imperfectly cultivated. Then also, in further example, in quite recent 
 years malaria entered and devastated the islands of Mauritius and 
 Reunion, practically destroying for a time the productiveness of these 
 rich colonies of Great Britain and France. 
 
 Creighton, in his article on malaria in the Encyclopaedia Britannica, 
 states that this disease " has been estimated to produce one-half of the 
 entire mortality of the human race; and inasmuch as it is the most 
 frequent cause of sickness and death in those parts of the globe that 
 are most densely populated, the estimate may be taken as at least 
 rhetorically correct." a 
 
 Is it possible to make any close estimate of the ratio between the 
 number of deaths from malaria and the number of cases of the same 
 malady ? No perfectly sound basis for such an estimate is apparent. 
 In the English translation of Celli's work on " Malaria According 
 to the New Researches," published in London in 1900, it is stated 
 that the mortality from malaria in Italy from 1887 to 1898 varied 
 from 21,033 in the first-named year to 11,378 in the last-named year, 
 and the mean mortality for the period is assumed to be about 15,000. 
 In 1896 a count of the patients in the hospitals in Rome was made, 
 and the mortality rate of 7.75 per thousand of the actual patients was 
 established. Calculating then on this basis, and at this rate, the num- 
 ber of cases per year for Italy was placed at about 2,000,000. Accord- 
 ing to this estimate, and with the average mortality for the United 
 States of 12,000 as above indicated, the approximate number of 
 cases for the United States would be about 1,550,000. It seems obvi- 
 ous, however, that Celli, in using the basis of hospital patients only, 
 must have underestimated the number of cases for the Kingdom, 
 since of the people in the country suffering from malaria the propor- 
 tion entering the hospital must be relatively small. Therefore the 
 death rate from malaria of malarial patients in the hospital must be 
 greater than the death rate from malaria of the people who suffer 
 from this disease in the whole country. In fact, so great must this 
 
 ° See " Darwinism and Malaria," by R. G. Eccles, M. D., Medical Record, 
 New York, January 16, 1909, pp. 85-93. 
 
12 LOSS THROUGH [NSBCTS THAT CARRY DISEASE. 
 
 discrepancy necessarily be that it would not seem at all unlikely to 
 the writer if the number of persons suffering from malaria in Italy 
 were in reality nearer 3,000.000 than 2.000.000. 
 
 The same argument will hold for the United States, and more 
 especially so since as a rule malaria in this country is of a lighter 
 type than in Italy; in fact an estimate of 3,000.000 case^ of malaria 
 in the United States annually is probably by no means too high. It 
 will not be an exaggeration to estimate that one-fourth of the produc- 
 tive capacity of an individual suffering with an average case of ma- 
 laria is lost. Accepting this as a basis, and including the loss through 
 death, the cost of medicines, the losses to enterprises in malarious 
 regions through the difficulty of securing competent labor, and other 
 factors, it is safe to place the annual loss to the United States from 
 malarial disease under present conditions at not less than one hundred 
 millions of dollars. Celli has shown that in Italy the great railway 
 industries, for example, feel the effect of malaria greatly. Accord- 
 ing to accurate calculations one company alone, for 1,400 kilometers 
 of railway and for 6,416 workmen in malarious zones, spends on ac- 
 count of malaria 1.050,000 francs a year. The same writer states that 
 the army in Italy from 1877 to 1897 had more than 300,000 cases of 
 malaria. 
 
 The loss to this country in the way of retardation of the develop- 
 ment of certain regions, owing to the presence of malaria, is extremely 
 great. Certain territory containing most fertile soil and capable of 
 the highest agricultural productiveness is practically abandoned. 
 With the introduction of proper drainage measures and antimosquito 
 work of other character, millions of acres of untold capacity could 
 be released from the scourge at a comparatively slight expenditure. 
 These regions in the absence of malaria would have added millions 
 upon millions to the wealth of the country. Drainage measures are 
 now being initiated by the United States. Parties of engineers are 
 being sent by the Government to make preliminary drainage sur- 
 ve} T s in the most prominent of these potentially productive regions. 
 The following statement concerning the effect of malaria on the 
 progress of this work has been made to the writer by Dr. George Otis 
 Smith, director of the United States Geological Survey : 
 
 " In one of the Southern States 11 topographic parties have been at 
 work during the past field season. The full quota for these parties 
 would be 55 men, but I believe that something over 100 men have 
 been employed at different times during the season. While I have 
 not exact figures before me, I feel warranted in the statement that at 
 least 95 per cent of these employees have been sick, for periods rang- 
 ing from a few days up to two weeks, in the hospital. Many of them 
 have been able later to return to work, but at least 30 per cent had 
 to leave the field permanently, Bv reason of this sickness the effi- 
 
MOSQUITOES AND MALARIA. 13 
 
 ciency of the parties was reduced, at a very conservative estimate, by 
 25 per cent. 
 
 " In my recent visit in this field I found one man sick in each of 
 the parties I saw and one man who had just returned from the 
 hospital leaving the field for good. A similar state of things was 
 reported from the other parties. I regard the sickness as practically 
 all of a malarial nature, as extreme care was taken in all the camps 
 to use nothing but boiled water except in a few instances where arte- 
 sian water from great depths w T as available. In all the camps the 
 tents have been screened, and in every case where the topographer has 
 lived for any time ' on the country ' there has been infection. As 
 illustrating the value of the precautions generally taken by our camp 
 parties, I might cite the fact that last year in West Virginia with 30 
 men living in camp, with typhoid fever prevalent in the neighborhood, 
 no cases developed, while with 6 men living on the country where 
 the same care could not be taken regarding the water supply, two 
 cases of typhoid developed." 
 
 In estimating the weight of Doctor Smith's statement, it must be 
 borne in mind that the men of his field parties are exceptionally in- 
 telligent and prepared to take all ordinary precautions. 
 
 Throughout the region in question malaria is practically universal. 
 The railroads suffer, and at the stations throughout the territory it is 
 practically impossible to keep operators steadily at work. This re- 
 duction in efficiency in the surveying parties and in the local railroad 
 officials is moreover probably very considerably less than the reduc- 
 tion in the earning capacity of the entire population, which, however, 
 is necessarily scanty. 
 
 In an excellent paper entitled " The relation of malaria to agricul- 
 tural and other industries of the South," published in the Popular 
 Science Monthly for April, 1903, Prof. Glenn W. Herrick, then of 
 the College of Agriculture of Mississippi, after a consideration of 
 the whole field, concludes that malaria is responsible for more sick- 
 ness among the white population of the South than any disease to 
 wmich it is now subject. The following forcible statement referring 
 to the States of Louisiana, Mississippi, Alabama, Georgia, and South 
 Carolina is in Professor Herrick's words: 
 
 " We must now T consider briefly what 635,000 or a million cases of 
 chills and fevers in one year mean. It is a self-evident truth that it 
 means well for the physician. But for laboring men it means an 
 immense loss of their time together with the doctors' fees in many 
 instances. If members of their families other than themselves be 
 affected, it may also mean a loss of time together with the doctors' 
 fees. For the employer it means the loss of labor at a time perhaps 
 when it would be of greatest value. If it does not mean the actual 
 loss of labor to the employer it will mean a loss in the efficiency of 
 
14 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 his labor. To the farmers it ma}^ mean the loss of their crops by 
 want of cultivation. It will always mean the noncultivation or 
 imperfect cultivation of thousands of acres of valuable land. It 
 means a listless activity in the world's work that counts mightily 
 against the wealth-producing power of the people. Finally it means 
 from two to five million or more days of sickness with all its attendant 
 distress, pain of body, and mental depression to some unfortunate 
 individuals of those five States." 
 
 Referring to the Delta region in Mississippi, which lies along the 
 Mississippi River in the western part of the State of Mississippi, 
 extending from the mouth of the Yazoo River north nearly to the 
 Tennessee line, Herrick says that it is the second best farming land 
 in the world, having only one rival, and that is the valley of the Nile. 
 " Still," says Herrick, " this land to-day, or at least much of it, can 
 be bought at ten to twenty dollars an acre. Thousands of acres in 
 this region are still covered with the primeval forest, and the bears 
 and deer still roaming there offer splendid opportunities for the 
 chase, as evidenced by the late visit of our Chief Executive to those 
 regions for the purpose of hunting. Why is not this land thickly 
 settled? And why is it not worth from two to five hundred dollars 
 an acre? If it produces from one to two or more bales of cotton to 
 an acre, and it does, it ought to be worth the above named figures. 
 A bale of cotton to the acre can be produced for thirteen dollars, 
 leaving a net profit of twenty to forty dollars for each bale, or forty 
 to eighty or more dollars for each acre of land cultivated. Moreover, 
 this land has been doing that for years, and will do it for years to 
 come, without the addition of one dollar's worth of fertilizer. Land 
 that will produce a net profit of forty to eighty dollars an acre is a 
 splendid investment at one, two, or even three hundred dollars an 
 acre. Yet this land does not sell in* the market for anything like so 
 much, because the demand is not sufficient, for white people positively 
 object to living in the Delta on account of malarial chills and fevers. 
 A man said to me not long ago that he would go to the Delta that day 
 if he were sure that his own life or the lives of the members of his 
 family would not be shortened thereby. There are thousands exactly 
 like him, and the only reason that these thousands do not go there to 
 buy lands and make homes is on account of chills and fevers. But 
 there is a time coming, and that not far distant, when malaria in the 
 Delta will not menace the would-be inhabitants. When that time 
 comes it will be the richest and most populous region in the United 
 States." 
 
 Malaria is a preventable disease. It is possible for the human 
 species to live and to thrive and to produce in malarious regions, but 
 at a very considerable inconvenience and expense. The Italian inves- 
 tigators, and especially Celli and his staff, have shown that by 
 
MOSQUITOES AND MALARIA. 15 
 
 screening the huts of the peasants on the Roman Campagna and by 
 furnishing field laborers with veils and gloves when exposed to the 
 night air, it is possible even in that famous hotbed of malaria to 
 conduct farming operations with a minimum of trouble from the 
 disease. Moreover, Koch and his assistants in German East Africa 
 have shown that it is possible, by stamping out the disease among 
 human beings by the free use of medicine, that a point can be gained 
 where there is small opportunity for the malarial mosquitoes to become 
 infected. Moreover, the work of the parties sent out by the Liverpool 
 School of Tropical Medicine and other English organizations to the 
 west coast of Africa has shown that by the treatment of malarial- 
 mosquito breeding pools the pernicious coast fever may be greatly 
 reduced. Again, the work of Englishmen in the Federated Malay 
 States has shown that large areas may be practically freed from 
 malaria. The most thorough and the most satisfactory of all meas- 
 ures consists in abolishing the breeding places of the malarial mos- 
 quitoes. In regions like the Delta of the Mississippi this involves 
 extensive and systematic drainage, but in very many localities where 
 the breeding places of the Anopheles mosquitoes can be easily eradi- 
 cated, where they are readily located and are so circumscribed as to 
 admit of easy treatment, it is possible to rid the section of malaria 
 at a comparatively slight expense. 
 
 With a general popular appreciation of the industrial losses caused 
 primarily by the malarial mosquito and secondarily by the forms 
 which do not carry malaria, as indicated in the opening paragraphs, 
 it is inconceivable that the comparatively inexpensive measures neces- 
 sary should not be undertaken by the General Government, by the 
 State governments, and by the boards of health of communities, just 
 as it is inconceivable that the individual should suffer from malaria 
 and from the attacks of other mosquitoes when he has individual 
 preventives and remedies at hand. Large-scale drainage measures 
 by the General Government involving large sections of valuable terri- 
 tory have been planned and are practically under way ; certain States, 
 notably New Jersey and New York, are beginning to work ; communi- 
 ties all over the country through boards of health are also beginning 
 to take notice, while popular education regarding the danger from 
 mosquitoes and in regard to remedial measures is rapidly spreading. 
 But all of this interest should be intensified, and the importance of 
 the work should be displayed in the most emphatic manner, and relief 
 from malaria and other mosquito conditions should be brought about 
 as speedily as possible. 
 
 A few excellent examples of antimalarial work may be instanced. 
 
 The latest reports on the measures taken to abolish malaria from 
 Klang and Port Swettenham in Selangor, Federated Malay States, 
 indicate the most admirable results. These measures were under- 
 
taken first in 1901 and 1902, and have been reported upon from time 
 to time in the Journal of Tropieal Medicine. The expenditure 
 undertaken by the Government with a view to improving the health 
 of the inhabitants of these towns has been fully justified by the 
 results, which promise to be of permanent value. The total expendi- 
 ture for the town of Klang down to the end of 1905 was £3,100 
 ($15,086), and the annual permanent expenditure is about £60 ($292) 
 for clearing earth drains and £210 ($1,022) for town gardeners. For 
 Port Swettenham the total expenditure to the end of 1905 was £7,000 
 ($34,065), and the annual cost of keeping up the drains, etc., is ap- 
 proximately £40 ($195) for clearing earth drains, and £100 ($487) 
 for town gardeners. 
 
 The careful tabulation of cases and deaths and of the results of 
 the examination of blood of children in especially drained areas 
 indicates the following conclusions: (1) Measures taken systematically 
 to destroy breeding places of mosquitoes in these towns, the inhabit- 
 ants of which suffered terribly from malaria, were followed almost 
 immediately by a general improvement in health and decrease in 
 death rate. (2) That this was due directly to the work carried out 
 and not to a general dying out of malaria in the district is clearly 
 shown by figures pointing out that while malaria has practically 
 ceased to exist in the areas treated it has actually increased to a 
 considerable extent in other parts of the district where antimalarial 
 measures have not been undertaken. 
 
 The statistics for 1905 are even more favorable than those for 1902, 
 which gives a very strong evidence in favor of the permanent nature 
 of the improvement carried out. In fact it seems as though malaria 
 has been permanently stamped out at Klang and Port Swettenham 
 by work undertaken in 1901, and this experience in the Malay States 
 should be of value to those responsible for the health of communities 
 similarly situated in many other parts of the world. 
 
 Another striking example of excellent work of this kind is found 
 in the recently published report on the suppression of malaria in 
 Ismailia, issued under the auspices of the Compagnie Universelle du 
 Canal Maritime de Suez. Ismailia is now a town of 8,000 inhabit- 
 ants. It w r as founded by De Lesseps in April, 1862, on the borders 
 of Lake Timsah, which the Suez Canal crosses at mid-distance be- 
 tween the Red Sea and the Mediterranean. Malarial fever made its 
 appearance in very severe form in September, 1877, although the 
 city had up to that time been very healthy, and increased so that 
 since 1886 almost all of the inhabitants have suffered from the fever. 
 In 1901 an attempt to control the disease was made on the mosquito 
 basis, and this attempt rapidly and completely succeeded, and after 
 two years of work all traces of malaria disappeared from the city. 
 The work was directed not only against Anopheles mosquitoes, but 
 
MOSQUITOES AND YELLOW FEVER. 17 
 
 against other culicids, and comprised- the drainage of a large swamp 
 and the other usual measures. The initial expense amounted to 
 50,000 francs ($9,650), and the annual expenses since have amounted 
 to about 18,300 francs ($3,532). 
 
 The results may be summarized about as follows: Since the be- 
 ginning of 1903 the ordinary mosquitoes have disappeared from 
 Ismailia. Since the autumn of 1903 not a single larva of Anopheles 
 has been found in the protected zone, which extends to the west for 
 a distance of 1,000 meters from the first houses in the Arabian 
 quarter and to the east for a distance of 1,800 meters from the first 
 houses in the EurojDean quarter. After 1902 malarial fever obviously 
 began to decrease, and since 1903 not a single neAv case of malaria 
 has been found in Ismailia. 
 
 A very efficient piece of antimalarial work was accomplished in 
 Havana during the American occupation of 1901 to 1902, incidental 
 in a way to the work against yellow fever. An Anopheles brigade 
 of workmen was organized under the sanitary officer, Doctor Gorgas, 
 for work along the small streams, irrigated gardens, and similar 
 places in the suburbs, and numbered from 50 to 300 men. No exten- 
 sive drainage, such as would require engineering skill, was attempted, 
 and the natural streams and gutters were simply cleared of obstruc- 
 tions and grass, while superficial ditches were made through the irri- 
 gated meadows. Among the suburban truck gardens Anopheles bred 
 everywhere, in the little puddles of water, cow tracks, horse tracks, 
 and similar depressions in grassy ground. Little or no oil was used 
 by the Anopheles brigade, since it was found in practice a simple 
 matter to drain these places. At the end of the year it was very diffi- 
 cult to find water containing mosquito larvae anywhere in the suburbs, 
 and the effect upon malarial statistics was striking. In 1900, the 
 year before the beginning of the mosquito work, there were 325 
 deaths from malaria; in 1901, the first year of the mosquito work, 
 171 deaths; in 1902, the second year of mosquito work, 77 deaths* 
 Since 1902 there has been a gradual though slower decrease, as fol- 
 lows: 1903, 51; 1904, 44; 1905, 32; 1906, 26; 1907, 23. These results, 
 although less striking than those from Ismailia, involved a smaller 
 expense in money and show surely an annual saving of 300 lives, and 
 undoubtedly a corresponding decrease in the number of malarial 
 cases, which may be estimated upon our earlier basis at something 
 less than 40,000. 
 
 YELLOW FEVER. 
 
 Yellow fever has prevailed endemically throughout the West In- 
 dies and in certain regions on the Spanish Main virtually since the 
 discovery of America. Barbados, Jamaica, and Cuba suffered 
 epidemics before the middle of the seventeenth century. There were 
 
 83434— Bull. 78—09 3 
 
18 LOSS THROUGH INSECTS THAT CABBY DISEASE. 
 
 outbreaks in Philadelphia, Charleston, and Boston as early as 1G92, 
 and for a hundred years there were occasional outbreaks, culminat- 
 ing in the great Philadelphia epidemic of 1793. Northern cities were 
 able, by rigid quarantine measures, to prevent great epidemics after 
 the early part of the nineteenth century, but from the West Indies 
 the disease was occasionally introduced and prevailed from time to 
 time epidemically in the Southern States. In 1853 it raged through- 
 out this region, New Orleans alone having a mortality of 8,000. The 
 last widespread epidemic occurred in 1878, chiefly in Louisiana, Ala- 
 bama, and Mississippi, but spreading up the Mississippi Valley as far 
 as Cairo, 111., and attacking with virulence the city of Memphis, Tenn. 
 In this year there were 125,000 cases and 12,000 deaths. In 1882 
 there were 192 deaths at Pensacola ; in 1887, G2 deaths in the Southern 
 States; in 1893, 52 deaths; in 1897, 484; in 1898, 2,456 cases with 
 117 deaths; in 1903, 139 deaths w T ere recorded, mostly at Laredo, 
 Tex., and in 1905 there was a serious outbreak at New Orleans and 
 in neighboring towns, including one locality in Mississippi, in which 
 911 deaths were recorded for the whole country. 
 
 The actual loss of life from yellow fever during all these years, 
 when compared with the loss from other diseases, has been compara- 
 tively slight, but the death rate is perhaps the most insignificant fea- 
 ture of the devastation which yellow fever epidemics have produced, 
 and the disease itself has been but a small part of the affliction which 
 it has brought to the Southern States. The disease once discovered in 
 epidemic form, the whole country has become alarmed; commerce 
 in the affected region has come virtually to a standstill; cities have 
 been practically deserted ; people have died from exposure in camping 
 out in the highlands ; rigid quarantines have been established ; inno- 
 cent persons have been shot while trying to pass these quarantine 
 lines; all industry for the time has ceased. The commerce of the 
 South during the epidemic of 1878, for example, fell off 90 per cent, 
 and the hardships of the population can not be estimated in monetary 
 terms. With such industrial and commercial conditions existing 
 from Texas to South Carolina, many industries at the North have 
 suffered, and, in fact, the effect of a yellow fever summer in the South 
 has been felt not only all over the United States, but in many other 
 portions of the world. 
 
 All these conditions, as bad as they have been, do not sum up the 
 total loss to the national prosperity during past years. Cities like 
 Galveston, New Orleans, Mobile, Memphis, Jacksonville, and Charles- 
 ton, subject to occasional epidemics, as they have been in the past, 
 have not prospered as they should have done. Their progress has 
 been greatly impeded by this one cause, and thus the industrial 
 development of the entire South has been greatly retarded. 
 
MOSQUITOES AXD YELLOW FEVER. 19 
 
 Physicians have been theorizing about the cause of yellow fever 
 from the time when they began to treat it. It was thought by many 
 that it was carried in the air; by others that it was conveyed by the 
 clothing, bedding, or other articles which had come in contact with a 
 yellow-fever patient. There were one or two early suggestions of the 
 agency of mosquitoes, but practically no attention was paid to them, 
 and they have been resurrected and considered significant onry since 
 the beginning of the present century. With the discovery of the 
 agency of micro-organisms in the causation of disease, a search soon 
 began for some causative germ. Many micro-organisms were found 
 in the course of the autopsies, and many claims Avere put forth by 
 investigators. All of these, however, were virtually set at rest by 
 Sternberg in his " Report on the Etiology and Prevention of Yellow 
 Fever." published in 1890, but a claim made by Sanarelli in June, 
 1897. for a bacillus which he called Bacillus Ictcroidcs received con- 
 siderable credence, and in 1899 it was accepted in full by Wasden and 
 Geddings. of the United States Marine-Hospital Service, who re- 
 ported that they had found this bacillus in thirteen or fourteen cases 
 of yellow fever in the city of Havana. There is no evidence, how- 
 ever, that this bacillus has anything to do with yellow fever. In 1881 
 Finlay. of Havana, proposed the theory that yellow fever, whatever 
 its cause may be. is conveyed by means of Culex (now Stegomyia) 
 fasciatus (now calopus). Subsequently he published several im- 
 portant papers, in which his views were modified from time to time, 
 and in the course of which he mentioned experiments with 100 indi- 
 viduals, producing 3 cases of mild fever. None of the cases, however, 
 was under his full control, and the possibility of other methods of 
 contracting the disease was not excluded. Therefore, his theory, 
 while it was received with interest, was not considered to be proved. 
 
 In 1900 came the beginning of the true demonstration. An army 
 board was appointed by Surgeon-General Sternberg for the purpose 
 of investigating the acute infectious diseases prevailing in the island 
 of Cuba. The result achieved by this board, consisting of Reed, 
 Carroll, Lazear, and Agramonte, was a demonstration that yellow 
 fever is carried by Stegomyia calopus, and their ultimate demonstra- 
 tion was so perfect as to silence practically all expert opposition. The 
 Third International Sanitary Convention of the American Republics 
 unanimously accepted the conclusion that yellow fever is carried by 
 this mosquito, and that the Stegomyia constitutes the only known 
 means by which the disease is spread. To-day, after abundant addi- 
 tional demonstration, the original contention of Reed. Carroll, and 
 Agramonte (Lazear having died in the course of the experiments) is 
 a part of the accepted knowledge of the medical world. The im- 
 portance of the discovery can not be overestimated, and its first 
 demonstration was followed by antimosquito measures in the city 
 
20 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 of Havana, undertaken under the direction of Gorgas. with startling 
 results. 
 
 Yellow fever had been endemic in Havana for more than one hun- 
 dred and fifty years, and Havana was the principal source of infec- 
 tion for the rest of Cuba. Other towns in Cuba could have rid 
 themselves of the disease if they had not been constantly reinfected 
 from Havana. By ordinary sanitary measures of cleanliness, im- 
 proved drainage, and similar means the death rate of the city w T as 
 reduced, from 1898 to 1900, from 100 per thousand. to 22 per thou- 
 sand; but these measures had no effect upon yellow fever, this disease 
 increasing as the nonimmune population following the Spanish war 
 increased, and in 1900 there was a severe epidemic. 
 
 Stegomyia calopus was established as the carrier of the fever 
 early in 1901, and then antimosquito measures were immediately 
 begun. Against adult mosquitoes no general measures were attemp- 
 ted, although screening and fumigation were carried out in quarters 
 occupied by yellow-fever patients or that had been occupied by 
 yellow -fever patients. It was found that the Stegomyia bred prin- 
 cipally in the rain-water collections in the city itself. The city was 
 divided into about 30 districts, and to each district an inspector and 
 two laborers were assigned, each district containing about a thousand 
 houses. An order was issued by the mayor of Havana requiring all 
 collections of water to be so covered that mosquitoes could not have 
 access, a fine being imposed in cases where the order was not obeyed. 
 The health department covered the rain-water barrels of poor fami- 
 lies at public expense. All cesspools w T ere treated with petroleum. 
 All receptacles containing fresh water Avhich did not comply with the 
 law were emptied and on the second offense destroyed. The result of 
 this work thoroughly done was to Avipe out A 7 elloAv fever in Havana, 
 and there has not been a certain endemic case since that time. 
 
 In the New Orleans epidemic of 1905, a striking illustration of the 
 value of this recently acquired mosquito-transmission knowledge is seen. 
 The presence of yellow fever in the city w T as first recognized about the 
 12th of July, and the plan of campaign adopted by the Board of Health 
 under Dr. Quitman Kohnke, from the beginning was based on the 
 mosquito conveyance of the disease. Available funds Avere rapidly 
 exhausted, hoAvever, and on the 12th of August the Public Health and 
 Marine-Hospital Service was put in charge of the situation and pro- 
 Added with ample means. By that time the increase in the neAv cases 
 and deaths rendered it practically certain that the disease Avas as Avide- 
 spread as during the terrible epidemic of 1878. There had been up to 
 that time 142 deaths from a total of 913 cases, as against 152 deaths 
 from a total of 519 cases in 1878. The Avork for the rest of the sum- 
 mer Avas continued with great energy under Doctor White, and the 
 measures Avere based almost entirely upon a Avarfare against the yel- 
 low-fever mosquito. The disease began almost immediately to abate, 
 and the result at the close of the season indicated 460 deaths, as 
 against 4,046 in 1878, a virtual saving of over 3,500 liA T es. The 
 
WORK AGAIXST MOSQUITOES IX PANAMA. 
 
 21 
 
 following table of deaths from yellow fever in New Orleans from 
 1847 to 1905 points out most strikingly the value of this antimosquito 
 work : 
 
 Table II. — Comparative table of deaths from yellow fever in New Orleans dur- 
 ing various years. 
 
 Month. 
 
 Year. 
 
 1847. 
 
 1848. 
 
 1863. 
 
 1354. 
 
 1855. 
 
 1858. 
 
 1867. 
 
 1878. 
 
 1905. 
 
 May 
 
 
 
 2 
 
 31 
 
 1,521 
 
 5,133 
 
 982 
 147 
 
 28 ! 
 
 4 
 
 
 
 
 
 
 June 
 
 
 4 
 
 33 
 
 200 
 
 467 
 
 126 
 
 20 
 
 ""22' 
 
 2 
 
 29 
 
 532 
 
 1,234 
 
 490 
 
 131 
 
 7 
 
 5 
 
 382 
 
 1,286 
 
 874 
 
 97 
 
 19 
 
 7 
 
 2 
 
 132 
 
 1,140 
 
 2,204 
 
 1.137 
 
 224 
 
 15 
 
 3 
 
 11 
 
 255 
 
 1, 637 
 
 1,072 
 
 103 
 
 26 
 
 
 
 July 
 
 74 
 
 965 
 
 1,100 
 
 198 
 
 12 
 
 10 
 
 445 
 
 26 
 1,025 
 1,780 
 1, 065 
 
 147 
 3 
 
 35 
 
 August 
 
 236 
 
 September 
 
 107 
 
 October 
 
 59 
 
 November 
 
 23 
 
 December 
 
 
 Months unknown 
 
 
 
 
 
 
 Total 
 
 2,804 
 
 872 
 
 7, Ms 
 
 2,425 
 
 2,670 
 
 4,854 
 
 3,107 
 
 4,046 
 
 460 
 
 
 
 The epidemics of 1818, 1854, and 1855 are least comparable with 
 that of 1905 because they immediately succeeded severe epidemics to 
 which were due very many immunes. 
 
 The population of Xew Orleans by the United States Census was 
 130,565 in 1850: 168,675 in 1860; 191.118 in 1870; 216,090 in 1880, 
 and 287,101 in 1900. 
 
 WORK ON THE ISTHMUS OF PANAMA. 
 
 The United States Government has very properly used the services 
 of Colonel Gorgas. who was in charge of the eminently successful 
 work at Havana, by appointing him chief sanitary officer of the 
 Canal Zone during the digging of the canal. In 1901 active work was 
 begun, and Colonel Gorgas was fortunate in having the services of 
 Mr. Le Prince, who had been chief of his mosquito brigades in Havana, 
 and therefore was perfectly familiar with antimosquito methods. In 
 Panama, as in Havana, the population had depended principally 
 upon rain water for domestic purposes, so that every house had cis- 
 terns, water barrels, and such receptacles for catching and storing 
 rain water. The city was divided up into small districts with an in- 
 spector in charge of each district. This inspector was required to 
 cover his territory at least twice a week and to make a report upon 
 each building with regard to its condition as to breeding places of 
 mosquitoes. All the cisterns, water barrels, and other water recepta- 
 cles in Panama were covered as in Havana, and in the water barrels 
 spigots were inserted so that the covers would not have to be taken 
 off. Upon first inspection, in March. 1,000 breeding places were 
 reported. At the end of October less than 100 containing larvae 
 were recorded. This gives one a fair idea of the consequent rapid 
 
22 IJ'SS THROUGH INSECTS THAT CABBY DISEASE. 
 
 decrease in the Dumber of mosquitoes in the city. These opera- 
 tions were directed primarily against the yellow-fever mosquito, and 
 incidentally against the other common species that inhabit rain-water 
 barrel-. Against the Anopheles in the suburbs the same kind of work 
 
 was done as was done in Havana, with exceptionally good results. 
 
 The same operation- were carried on in the villages between Pan- 
 ama and Colon. There are some twenty of these villages, running 
 from 500 to 3.000 inhabitants each. Not a single instance of failure 
 has occurred in the disinfection of these small town-, and the result 
 of the whole work has been the apparent elimination of yellow fever 
 and the very great reduction of malarial fever. 
 
 The remarkable character of these results can only be judged accu- 
 rately by comparative methods. It is well known that during the 
 French occupation there was an enormous mortality among the 
 European employees, and this was a vital factor in the failure of the 
 work. Exact losses can not be estimated, since the work was done 
 under 17 different contractors. These contractors were charged Si 
 a day for every sick man to be taken care of in the hospital of the 
 company. Therefore it often happened that when a man became 
 sick his employer discharged him, so that he would not have to bear 
 the expense of hospital charge^. There was no police patrol of the 
 territory and many of these men died along the line. Colonel 
 Gorgas has stated that the English consul, who was at the Isthmus 
 during the period of the French occupation, is inclined to think 
 that more deaths of employees occurred out of the hospital than in it. 
 A great many were found to have died along the roadside while en- 
 deavoring to find their way to the city of Panama. The old superin- 
 tendent of the French hospital >tate- that one day 3 of the medical 
 staff died from yellow fever, and in the same month 9 of the medical 
 staff. Thirty-six Roman Catholic sisters were brought over a- nurses, 
 and 24 died of yellow fever. On one vessel l v young French engi- 
 neer- came over, and in a month after their arrival all but one died. 
 
 Now that the relation of the mosquito to yellow fever is well under- 
 stood, it was found during the first two years under Doctor Gorgas 
 that, although there were constantly one or more yellow-fever cases 
 in the hospital, and although the nurses and physicians were all non- 
 immunes, not a single case of yellow fever was contracted in that 
 way. The nurses never seemed to consider that they were running 
 any risk in attending yellow fever ca.-e> night and day in screened 
 ward-, and the wives and families of officers connected with the hos- 
 pital lived about the ground.-, knowing that yellow fever was con- 
 stantly being brought into the ground- and treated in near-by build- 
 Americans, sick from any cause, had no fear when being 
 treated in beds immediately adjoining those of yellow-fever pa- 
 tients. Colonel Gorgas and Doctor Carter lived in the old ward 
 
THE TYPHOID FLY, OR HOUSE FLY. 23 
 
 used by the French for their officers, and Colonel Gorgas thinks it 
 safe to say that more men had died from yellow fever in that build- 
 ing under the French regime than in airy other building of the same 
 capacity at present standing. He and Doctor Carter had their wives 
 and children with them, which would formerly' have been considered 
 the height of recklessness, but they looked upon themselves, under the 
 now recognized precautions, as being as safe, almost, as they would 
 have been in Philadelphia or Boston. 
 
 Xo figures of the actual cost of the antimosquito work, either in 
 Havana or in the Panama Canal Zone, are accessible to the writer, 
 but it is safe to say that it was not exorbitant, and that it was not 
 beyond the means of any well-to-do community in tropical regions. 
 
 THE TYPHOID FLY, COMMONLY KNOWN AS THE HOUSE FLY. 
 
 The name " typhoid fly " is here proposed as a substitute for the 
 name " house fly." now in general use. People have altogether too 
 long considered the house fly as a harmless creature, or, at the most, 
 simply a nuisance. "While scientific researches have shown that it is 
 a most dangerous creature from the standpoint of disease, and while 
 popular opinion is rapidly being educated to the same point, the 
 retention of the name house fly is considered inadvisable, as perpetu- 
 ating in some degree the old ideas. Strictly speaking, the term 
 "typhoid fly" is open to some objection, as conveying the erroneous 
 idea that this fly is solely responsible for the spread of typhoid, but 
 considering that the creature is dangerous from every point of view, 
 and that it is an important element in the spread of typhoid, it 
 seems advisable to give it a name which is almost wholly justified and 
 which conveys in itself the idea of serious disease. Another repul- 
 sive name that might be given to it is " manure fly," but recent 
 researches have shown that it is not confined to manure as a breeding 
 place, although perhaps the great majority of these flies are born 
 in horse manure. For the end in view. ** typhoid fly " is considered 
 the best name. 
 
 The true connection of the so-called house fly with typhoid fever 
 and the true scientific evidence regarding its role as a carrier of that 
 disease have onh T recently been worked out. Celli in 1888 fed flies 
 with pure cultures of the typhoid bacillus, and examined their 
 contents and dejections microscopically and culturally. Inocu- 
 lations of animals were also made, proving that the bacilli which 
 passed through flies were virulent. Dr. George M. Kober, familiar 
 with Celli's researches, in his report on the prevalence of tj^phoid 
 fever in the District of Columbia, published in 1895, called especial 
 attention to the danger of the contamination of food supplies by 
 
24 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 flies coming from the excreta of typhoid patients. The prevalence of 
 typhoid fever in the concentration camps of the United State- Army 
 in the summer of 1808 brought about the appointment of an army 
 board of medical officers consisting of Drs. Walter Reed, U. S. Arm v. 
 Victor C. Vaughan, U. S. Volunteers, and E. O. Shakespeare, U. S. 
 Volunteers, to investigate the causes. The abstract of the report of 
 this board, published in 11)00. contains (p. 183) the following conclu- 
 sions with regard to flies : 
 
 "Flies undoubtedly served as carriers of the infection. 
 
 " Flies swarmed over infected fecal matter in the pits and then 
 visited and fed upon the food prepared for the soldiers at the mess 
 tents. In some instances where lime had recently been sprinkled 
 over the contents of the pits, flies with their feet whitened with lime 
 Avere seen walking over the food. 
 
 " It is possible for the fly to carry the typhoid bacillus in two 
 ways. In the first place, fecal matter containing the typhoid germ 
 may adhere to the fly and be mechanically transported. In the 
 second place, it is possible that the typhoid bacillus may be carried 
 in the digestive organs of the fly and may be deposited with its 
 excrement." 
 
 Doctor Vaughan, of the board just mentioned, in a paper read be- 
 fore the annual meeting of the American Medical Association at 
 Atlantic City, N. J., June G, 1900, gives the following additional rea- 
 sons for believing that flies were active in the dessemination of 
 typhoid fever: 
 
 " Officers whose mess tents were protected by means of screens 
 suffered proportionately less from typhoid fever than did those 
 whose tents were not so protected. 
 
 " Typhoid fever gradually disappeared in the fall of 1898, with 
 the approach of cold weather, and the consequent disabling of the fly." 
 
 There were also many important conclusions which bear upon the 
 fly question. For example, it was shown that every regiment in the 
 United States service in 1898 developed typhoid fever, nearly all of 
 them within eight weeks after assembling in camps. It not only 
 appeared in every regiment in the service, but it became epidemic 
 both in small encampments of not more than one regiment and in the 
 larger ones consisting of one or more corps. All encampments 
 located in the Northern as well as in the Southern States exhibited 
 typhoid in epidemic form. The miasmatic theory of the origin of 
 typhoid fever and the pythogenic theory ° were not supported by 
 the investigations of the commission, but the doctrine of the specific 
 
 a This theory is founded upon the belief that the colon germ may undergo a 
 ripening process by means of which its virulence is so increased and altered 
 that it may be converted into the typhoid bacillus or at least may become the 
 active agent in the causation of typhoid fever. 
 
THE TYPHOID FLY, OR HOUSE FLY. 25 
 
 origin of the fever was confirmed. The conclusion was reached that 
 the fever is disseminated by the transference of the excretions of an 
 infected individual to the alimentary canals of others, and that a 
 man infected with typhoid fever may scatter the infection in every 
 latrine or regiment before the disease is recognized in himself , while 
 germs may be found in the excrement for a long time after the 
 apparently complete recovery of the patient. Infected water was 
 not an important factor in the spread of typhoid in the national 
 encampments of 1898, but about one-fifth of the soldiers in the 
 national encampments in the United States during that summer de- 
 veloped this disease, while more than 80 per cent of the total deaths 
 were caused by typhoid. 
 
 In 1899 the writer began the study of the typhoid or house fly 
 under both country and city conditions. He made a rather thorough 
 investigation of the insect fauna of human excrement, and made a 
 further investigation of the species of insects that are attracted to 
 food supplies in houses. In a paper entitled "A Contribution to the 
 Study of the Insect Fauna of Human Excrement (with special refer- 
 ence to the spread of typhoid fever by flies) ," published in the Pro- 
 ceedings of the Washington Academy of Sciences, Volume II, pages 
 541-604, December 28, 1900, he showed that 98.8 per cent of the whole 
 number of insects captured in houses throughout the whole country 
 under the conditions indicated above were Musca domestica, the 
 typhoid or house fly. He showed further that this fly, while breeding 
 most numerously in horse stables, is also attracted to human excre- 
 ment and will breed in this substance. It was shown that in towns 
 where the box privy was still in existence the house fly is attracted to 
 the excrement, and, further, that it is so attracted in the filthy regions 
 of a city where sanitary supervision is lax and where in low alleys 
 and corners and in vacant lots excrement is deposited by dirty people. 
 He stated that he had seen excrement which had been deposited over- 
 night in an alleyway in South Washington swarming with flies under 
 the bright sunlight of a June morning (temperature 92° F.), and that 
 within 30 feet of these deposits ^vere the open windows and doors of 
 the kitchens of two houses kept by poor people, these two houses 
 being only elements in a long row. The following paragraph is 
 quoted from the paper just cited: 
 
 " Now. when we consider the prevalence of typhoid fever and that 
 virulent typhoid bacilli may occur in the excrement of an individual 
 for some time before the disease is recognized in him, and that the 
 same virulent germs may be found in the excrement for a long time 
 after the apparent recovery of a patient, the wonder is not that ty- 
 phoid is so prevalent but that it does not prevail to a much greater 
 
26 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 extent. Box privies should be abolished in every community. The 
 depositing of excrement in the open within town or city limits should 
 be considered a punishable misdemeanor in communities which have 
 not already such regulations, and it should be enforced more rigor- 
 ously in towns in which it is already a rule. Such offenses are gener- 
 ally committed after dark, and it is often difficult or even impossible 
 to trace the offender ; therefore, the regulation should be carried even 
 further and require the first responsible person w T ho notices the de- 
 posit to immediately inform the police, so that it may be removed or 
 covered up. Dead animals are so reported ; but human excrement is 
 much more dangerous. Boards of health in all communities should 
 look after the proper treatment or disposal of horse manure, primarily 
 in order to reduce the number of house flies to a minimum, and all 
 regulations regarding the disposal of garbage and foul matter should 
 be made more stringent and should be more stringently enforced." 
 
 In the opening sentence of the paragraph just quoted attention was 
 called to the activity of bacilli in excreta passed by individuals after 
 apparent recovery from typhoid. Since the paper in question was 
 published, more especial attention has been drawn by medical men 
 to this point, and it has been shown that individuals who are chronic 
 spreaders of the typhoid germs are much more abundant than was 
 formerly supposed. Dr. George A. Soper recently discovered a strik- 
 ing case of this kind in the person of a cook employed successively 
 by several families in the vicinity of New York City, with the result 
 that several cases of typhoid occurred in each of these families. In 
 a paper by Doctor Davids and Professor Walker, read before the 
 Royal Sanitary Institute of London during the present season, the 
 history was given of four personal carriers of typhoid who had com- 
 municated the disease to a number of people. These four carriers 
 were detected in one city within a few months, and from this fact 
 it can be argued with justice that such cases are comparatively numer- 
 ous. This being true, the presence of unguarded miscellaneous 
 human excreta deposited in city suburbs, in vacant lots, and in low 
 alleyways intensifies to a very marked degree the danger that the food 
 will become contaminated with typhoid bacilli by means of the ty- 
 phoid or house fly. It is known, too, that the urine of persons who 
 have suffered from typhoid fever often contains active typhoid bacilli 
 for several weeks after the patients have recovered ; consequently this 
 also is a source of danger. 
 
 The importance of the typhoid fly as a carrier of the disease in army 
 camps, as shown in the Spanish war and in the Boer war and in the 
 camps of great armies of laborers engaged in gigantic enterprises like 
 the digging of the Panama canal, is obvious, but what has just been 
 stated indicates that even under city conditions the influence of this 
 fly in the spread of this disease has been greatly underestimated. It 
 is not claimed that under city conditions the house fly becomes by this 
 argument a prime factor in the transfer of the disease, but it must 
 obviously take a much higher relative rank among typhoid conveyers 
 
THE TYPHOID FLY, OR HOUSE FLY. 27 
 
 than it has hitherto assumed. Perhaps even under city condition- 
 it must assume third rank— next to 'water and milk.° 
 
 It is not alone as a carrier of typhoid that this fly is to be feared. 
 In the same way it may carry nearly all the intestinal diseases. It is 
 a prime agent in the spreading of summer dysentery, and in this way 
 is unquestionably responsible for the death of many children in sum- 
 mer. One of the earliest accurate scientific studies of the agency of 
 insects in the transfer of human disease was in regard to flies as 
 spreaders of cholera. The belief in this agency long preceded its 
 actual proof. Dr. G. E. Nicholas, in the London Lancet, Volume II, 
 1873, page 72-1, is quoted by Xuttall as writing as follows regarding 
 the cholera prevailing at Malta in 1849 : " My first impression of the 
 possibility of the transfer of the disease by flies was derived from the 
 observation of the manner in which these voracious creatures, present 
 in great numbers, and having equal access to the dejections and food 
 of patients, gorged themselves indiscriminately and then disgorged 
 themselves on the food and drinking utensils. In 1850 the Superb, 
 in common with the rest of the Mediterranean squadron, was at sea 
 for nearly six months; during the greater part of the time she had 
 cholera on board. On putting to sea, the flies were in great force; 
 but after a time the flies gradually disappeared, and the epidemic 
 slowly subsided. On going into Malta Harbor, but without com- 
 municating with the shore, the flies returned in greater force, and the 
 cholera also with increased violence. After more cruising at sea, the 
 flies disappeared gradually with the subsidence of the disease.'' 
 
 Accurate scientific bacteriological observations by Tizzoni and 
 Cattani in 1886 showed definitely active cholera organisms in the 
 dejecta of flies caught in the cholera wards in Bologna, Italy. These 
 observations were subsequently verified and extended by Simonds, 
 Offelmann, Macrae, and others. 
 
 With tropical dysentery and other enteric diseases practically the 
 same conditions exist. In a report by Daniel D. Jackson to the 
 committee on pollution, of the Merchants' Association in New York, 
 published in December, 1907, the results of numerous observations 
 upon the relation of flies to intestinal diseases are published, and the 
 relation of deaths from intestinal diseases in New York City to the 
 
 a Dr. John R. Mohler, of the Bureau of Animal Industry, U. S. Department 
 of Agriculture, informs the writer that investigations made in his office show 
 that typhoid bacilli will live in butter under common market conditions for 151 
 days and still be able to grow when transferred to suitable conditions. In 
 milk under market conditions they retain active motility for 20 days, after 
 which time there is a gradual lessening in numbers until, on the forty-third day 
 of the test, they disappear from view. At certain seasons, of the year large num- 
 bers of flies collect upon the vats in which milk and cream are being stored 
 in dairies and creameries. Many of the flies fall in, their bodies being strained 
 out when the cream is sent to the churn. If any of these flies carry typhoid 
 bacilli these are washed off by the milk and remain in the butter or cheese 
 made from it. Thus the eating of butter contaminated in this way may account 
 for very many cases of typhoid fever the cause of which can not be otherwise 
 traced. 
 
28 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 activity and prevalence of the common house fly is shown not only 
 by repeated observations but also by an interesting plotting of the 
 curve of abundance of flies in comparison with the plotted curve of 
 abundance of deaths from intestinal diseases, indicating that the 
 greatest number of flies occurred in the weeks ending July 27 and 
 August 3 ; also, that the deaths from intestinal diseases rose above 
 the normal at the same time at which flies became prevalent, culmi- 
 nated at the same high point, and fell off with slight lag at the 
 time of the gradual falling off of the prevalence of the insects. 
 
 Similar studies have been carried on during the summer of 1908 
 in the city of Washington , and the curve of typhoid-fly abundance 
 for the whole city, as well as that for a district comprising eight city 
 squares in which intensive studies have been made both of flies and 
 of disease, will be plotted at the close of the season. At the time 
 of present writing this work has. not been completed. 
 
 The typhoid fly also possesses importance as a disseminator of the 
 bacilli of tuberculosis. In a paper by Dr. Frederick T. Lord, of 
 Boston, reprinted from the Boston Medical and Surgical Journal for 
 December 15, 1904, pages 651-654, the following conclusions are 
 reached : 
 
 " 1. Flies may ingest tubercular sputum and excrete tubercle ba- 
 cilli, the virulence of which may last for at least fifteen day-. 
 
 " 2. The danger of human infection from tubercular flyspecks is 
 by the ingestion of the specks on food. Spontaneous liberation of 
 tubercle bacilli from flyspecks is unlikely. If mechanically dis- 
 turbed, infection of the surrounding air may occur. 
 
 "As a corollary to these conclusions, it is suggested that — 
 
 " 3. Tubercular material (sputum, pus from discharging sinuses. 
 fecal matter from patients with intestinal tuberculosis, etc.) should 
 be carefully protected from flies, lest they act as disseminators of the 
 tubercle bacilli. 
 
 " 4. During the fly season greater attention should be paid to the 
 screening of rooms and hospital wards containing patients with 
 tuberculosis and laboratories where tubercular material is examined. 
 
 " 5. As these precautions would not eliminate fly infection by 
 patients at large, foodstuffs should be protected from flies which may 
 already have ingested tubercular material." 
 
 From all these facts it appears that the most important part played 
 by the typhoid fly or house fly in the human economy is to carry 
 bacteria from one place to another. The following table and com- 
 ments are taken from Bulletin Xo. 51 (April, 1908). of the Storrs 
 Agricultural Experiment Station, Storrs, Conn., entitled " Sources of 
 Bacteria in Milk." bv W. M. Esten and C. J. Mason : 
 
THE TYPHOID FLY, OR HOUSE FLY. 
 
 29 
 
 Table III. — Sources of bacteria from Jli 
 
 1907. 
 July 27 
 
 July 27 
 
 Aug. 6 
 
 Aug.14 
 
 Aug. 14 
 
 Sept. 4 
 
 Sept.21 
 
 Sept. 21 
 
 Sept.27 
 
 Aug. 20 
 
 Source. 
 
 (a) 1 fly, bacteriological 
 laboratory 
 
 (b) 1 fly. bacteriological 
 laboratory 
 
 (c) 19 cow-stable flies 
 
 Average per fly 
 
 (d) 94 swill-barrel flies 
 
 Average per fly 
 
 (c) 144 pigpen flies 
 
 Average per fly 
 
 (/) 18 swill-barrel flies 
 
 Average per fly 
 
 (g) 30 dwelling-house flies. 
 
 Average per fly 
 
 (h) 26 dwelling-house flies. 
 
 Average per fly 
 
 (i) 110 dwelling-house flies. 
 
 Average per fly 
 
 (j) 1 large bluebottle 
 blowfly 
 
 Total Total acid 
 number. bacteria. 
 
 3,150 
 
 550 
 
 7. 980, 000 
 
 420, 000 
 
 155, 000, 000 
 
 1,660,000 
 
 133, 000, 000 
 
 923,000 
 
 118,800,000 
 
 6, 600, 000 
 
 1, 425, 000 
 
 47,580 
 
 22, 880, 000 
 
 880,000 
 
 35,500,000 
 
 322, 700 
 
 308, 700 
 
 220 
 
 11 
 
 8,950 
 
 95 
 
 2,110 
 
 18, 
 
 10, 480 
 
 2, 182, 
 
 125, 
 
 4; 
 
 22, 596 
 
 869 
 
 13, 670 
 
 124; 
 
 250 
 
 100 
 ,000 
 ,600 
 ,000 
 ,300 
 ,000 
 ,700 
 ,000 
 ,000 
 ,000 
 
 167 
 ,000 
 ,000 
 ,000 
 
 200 
 
 Rapid 
 liquefy- 
 ing bac- 
 teria. 
 
 («) 
 
 600 
 
 
 
 
 
 
 
 100,000 
 700 
 
 
 
 
 
 120,000 
 4,600 
 
 840,000 
 80,300 
 
 Slow 
 liquefy- 
 ing bac- 
 teria. 
 
 100 
 
 
 
 20,000 
 
 1,000 
 
 
 
 
 
 266,000 
 
 1,150 
 
 4, 320, 000 
 
 46,000 
 
 933,000 
 
 6,500 
 
 14,500.000 10,480,000 
 804.000 I 582,000 
 
 Bacterium 
 
 lactis 
 
 acidi. 
 
 Group A. 
 
 Class 1. 
 
 Coli-sero- 
 
 genes. 
 Group A. 
 Class 2. 
 
 12,500 
 
 417 
 
 34,000 
 
 1,300 
 
 125,000 
 
 1.100 
 
 Total average of 414 flies . . 1 , 222, 570 
 Average per cent of 414 
 flies 
 
 Average per fly of 256 j 
 
 flies, experiments (d), ! 
 
 (e),and(/) 3,061,000 
 
 Average per cent of 256 
 
 flies, experiments (d), < 
 
 (0,and (/) 
 
 367, 300 
 
 7,830 
 
 30 
 
 6 
 
 765,000 
 
 230 
 
 „ 
 
 
 
 
 73,500 
 
 268, 700 
 8 
 
 211,500 
 
 7 
 
 4, 630, 000 
 49,300 
 
 1,176,000 
 
 12,200 
 
 30,000,000 
 
 1,600,000 
 
 ; 53, 800 
 18 
 
 a 2,200 mold spores. 
 
 " From the above table the bacterial population of 414 flies is pretty 
 well represented. The domestic fly is passing from a disgusting nui- 
 sance and troublesome pest to a reputation of being a dangerous 
 enemy to human health. A species of mosquito has been demon- 
 strated to be the cause of the spread of malaria. Another kind of 
 mosquito is the cause of yellow fever, and now the house fly is con- 
 sidered an agency in the distribution of typhoid fever, summer com- 
 plaint, cholera infantum, etc. 
 
 " The numbers of bacteria on a single fly may range all the way 
 from 550 to 6,600,000. Early in the fly season the numbers of bac- 
 teria on flies are comparatively small, while later the numbers are 
 comparatively very large. The place where flies live also determines 
 largely the numbers that they carry. The average for the 414 flies 
 was about one and one-fourth million bacteria on each. It hardly 
 seems possible for so small a bit of life to carry so large a number of 
 organisms. The method of the experiment was to catch the flies from 
 the several sources by means of a sterile fly net, introduce them into 
 a sterile bottle, and pour into the bottle a known quantity of steril- 
 ized water, then shake the bottle to wash the bacteria from their 
 bodies, to simulate the number of organisms that would come from a 
 fly in falling into a lot of milk. In experiments ' dj i <?,' and ' / ' 
 
30 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 the bacteria were analyzed into four groups. The objectionable class, 
 coli-cerogenes type, was two and one-half times as abundant as the 
 favorable acid type. If these flies stayed in the pigpen vicinity there 
 would be less objection to the flies and the kinds of organisms they 
 carry, but the fly is a migratory insect and it visits everything ' under 
 the sun/ It is almost impossible to keep it out of our kitchens, din- 
 ing rooms, cow stables, and milk rooms. The only remedy for this 
 rather serious condition of things is, remove the pigpen as far as pos- 
 sible from the dairy and dwelling house. Extreme care should be 
 taken in keeping flies out of the cow stable, milk rooms, and dwell- 
 ings. Flies walking over our food are the cause of one of the worst 
 contaminations that could occur from the standpoint of cleanliness 
 and the danger of distributing disease germs." 
 
 The danger of the typhoid or house fly in the carriage of disease 
 has thus been abundantly demonstrated. Further than this, it is an 
 intolerable nuisance. With mosquitoes it necessitates an annual out- 
 lay for window and door screens in the United States of not less than 
 ten millions of dollars. As a carrier of disease it causes a loss of 
 many millions of dollars annually. Dr. G. N. Kober, in a paper pre- 
 pared for the Governors' Conference on the Conservation of Natural 
 Resources, held at the White House in May, 1908, entitled " The Con- 
 servation of Life and Health by Improved Water Supply," presented 
 figures showing that the decrease in the vital assets of the country 
 through typhoid fever in a single } T ear is more than $350,000,000. 
 The house fly, as an important agent in the spread of this disease, is 
 responsible for a very considerable portion of this decrease in vital 
 assets. As an agency in the spread of other intestinal diseases, this 
 sum must be greatly increased, and }^et it is allowed to breed unre- 
 stricted all over the United States; it is allowed to enter freely the 
 houses of the great majority of our people; it is allowed to spread 
 bacteria freely over our food supplies in the markets and in the 
 kitchens and dining rooms of private houses, and, to use the happy 
 phraseology of Dr. Theobald Smith, " when we go into public restau- 
 rants in midsummer Ave are compelled to fight for our food with the 
 myriads of house flies which we find there alert, persistent, and 
 invincible." 
 
 Even if the typhoid or house fly were a creature difficult to de- 
 stroy, the general failure on the part of communities to make any 
 efforts whatever to reduce its numbers could properly be termed 
 criminal neglect; but since, as will be shown, it is comparatively an 
 easy matter to do away with the plague of flies, this neglect becomes 
 an evidence of ignorance or of a carelessness in regard to disease- 
 producing filth which to the informed mind constitutes a serious blot 
 on civilized methods of life. 
 
THE TYPHOID FLY, OR HOUSE FLY. 31 
 
 Strange as it may seem, an exhaustive study of the conditions 
 which produce house flies in numbers has never been made. The 
 life history of the insect in general was, down to 1873, mentioned in 
 only three European works and few exact facts were given. In 1873 
 Dr. A..S. Packard, then of Salem, Mass., studied the transformations 
 of the insect and gave descriptions of all stages, showing that the 
 growth of a generation from the egg state to the adult occupies from 
 10 to 14 days. 
 
 In 1895 the writer traced the life history in question, indicating 
 that 120 eggs are laid by a single female, and that in Washington, 
 in midsummer, a generation is produced every 10 days. Although 
 numerous substances were experimented with, he was able to breed 
 the fly only in horse manure. Later investigations indicated that the 
 fly will breed in human excrement and in other fermenting vegetable 
 and animal material, but that the vast majority of the flies that 
 infest dwelling houses, both in cities and on farms, come from horse 
 manure. 
 
 In 1907 careful investigations carried on in the city of Liverpool 
 by Robert Xewstead, lecturer in economic entomology and para- 
 sitology in the School of Tropical Medicine of the University of 
 Liverpool, indicated that the chief breeding places of the house fly 
 in that city should be classified under the following heads : 
 
 (1) Middensteads (places where dung is stored) containing horse 
 manure only. 
 
 (2) Middensteads containing spent hops. 
 
 (3) Ash pits containing fermenting materials. 
 
 He found that the dung heaps of stables containing horse manure 
 only were the chief breeding places. Where horse and cow manures 
 were mixed the flies bred less numerously, and in barnyards where 
 fowls were kept and allowed freedom relatively few of the house 
 flies were found. Only one midden containing warm spent hops was 
 inspected, and this was found to be as badly infested as any of the 
 stable middens. A great deal of time was given to the inspection of 
 ash pits, and it was found that wherever fermentation had taken 
 place and artificial heat had been thus produced, such places were 
 infested with house-fly larva? and pupa?, often to the same alarming 
 extent as in stable manure. Such ash pits as these almost invariably 
 contained large quantities of old bedding or straw and paper, paper 
 mixed with human excreta, or old rags, manure from rabbit hutches, 
 etc., or a mixture of all these. About 25 per cent of the ash pits 
 examined were thus infested, and house flies were found breeding 
 in smaller numbers in ash pits in which no heat had been engendered 
 by fermentation. The house fly was also found breeding by Mr. 
 Newstead in certain temporary breeding places, such as collections 
 
32 LOSS THROUGH IXSKCTS THAI CABBY DISEASE. 
 
 of fermenting vegetable refuse, accumulations of manure at the 
 wharves, and in bedding in poultry pens. 
 
 Still more recent investigations were carried on during 1908 by 
 Prof. S, A. Forbes, State entomologist of Illinois, who has reared it 
 in large numbers from the contents of paunches of slaughtered cattle, 
 from refuse hog hairs, from tallow vats, from carcasses of various 
 animals, miscellaneous garbage, and so on. 
 
 All this means that if we allow the accumulation of filth we will 
 have house flies, and if we do not allow it to accumulate we will have 
 no house flies. With the careful collection of garbage in cans and 
 the removal of the contents at more frequent intervals than 10 days, 
 and with the proper regulation of abattoirs, and more particularly 
 with the proper regulation of stables in which horses are kept, the 
 typhoid fly will become a rare species. It will not be necessary to 
 treat horse manure with chlorid of lime or with kerosene or with a 
 solution of Paris green or arsenate of lead, if stable men are required 
 to place the manure daily in a properly covered receptacle and if it 
 is carried away once a week. 
 
 The orders of the health department of the District of Columbia, 
 published May 3. 1900, if carried out will be very effective. These 
 orders may be briefly condensed as follows: 
 
 All stalls in which animals are kept shall have the surface of the 
 ground covered with a water-tight floor. Every person occupying 
 a building where domestic animals are kept shall maintain, in con- 
 nection therewith, a bin or pit for the reception of manure, and pend- 
 ing the removal from the premises of the manure from the animal 
 or animals shall place such manure in said bin or pit. This bin shall 
 be so constructed as to exclude rain water, and shall in all other re- 
 spects be water-tight, except as it may be connected with the public 
 sewer. It shall be provided with a suitable cover and constructed 
 so as to prevent the ingress and egress of flies. No person owning 
 a stable shall keep any manure or permit any manure to be kept in 
 or upon any portion of the premises other than the bin or pit de- 
 scribed, nor shall he allow any such bin or pit to be overfilled or 
 needlessly uncovered. Horse manure may be kept tightly rammed 
 into well-covered barrels for the purpose of removal in such barrels. 
 Every person keeping manure in any of the more densely populated 
 parts of the District shall cause all such manure to be removed from 
 the premises at least twice every week between June 1 and October 31, 
 and at least once every week between November 1 and May 31 of 
 the following year. Xo person shall remove or transport any manure 
 over any public highway in any of the more densely populated parts 
 of the District except in a tight vehicle, which, if not inclosed, must 
 be effectually covered with canvas, so as to prevent the manure from 
 being dropped. Xo person shall deposit manure removed from the 
 
THE TYPHOID FLY, OR HOUSE FLY. 33 
 
 bins or pits within any of the more densely populated parts of the 
 District without a permit from the health officer. Any person 
 violating any of these provisions shall, upon conviction thereof, be 
 punished by a fine of not more than $40 for each offense. 
 
 In addition to this excellent ordinance, others have been issued 
 from the health department of the District of Columbia which provide 
 against the contamination of exposed food by flies and by dust. The 
 ordinances are excellently worded so as to cover all possible cases. 
 They provide for the registration of all stores, markets, cafes, lunch 
 rooms, or of any other place where food or beverage is manufactured 
 or prepared for sale, stored for sale, offered for sale, or sold, in order 
 to facilitate inspection, and still more recent ordinances provide for 
 the registration of stables. An excellent campaign was begun during 
 the summer of 1908 against insanitary lunch rooms and restaurants. 
 A number of cases were prosecuted, but conviction was found to be 
 difficult. 
 
 For one reason or another, the chief reason being the lack of a 
 sufficient force of inspectors under the control of the health officers, 
 the ordinance in regard to stables has not been carried out with that t 
 perfection which the situation demands. In the summer of 1896, the 
 health officer of the District, Dr. W. C. Woodward, designated a 
 region in Washington bounded by Pennsylvania avenue, Sixth street, 
 Fifteenth street, and the Potomac River, which was to be watched 
 by assistants of the writer. Twenty- four stables were located in this 
 region and were visited weekly by two assistants chosen for the pur- 
 pose. The result was that on the whole the manure was well looked 
 after and the number of flies in the region in question was very con- 
 siderably reduced during the time of inspection. 
 
 Were simple inspection of stables all that is needed, a force of four 
 inspectors, specially detailed for this work, could cover the District 
 of Columbia, examining every stable, after they were once located and 
 mapped, once a week. The average salary of an inspector is $1,147, 
 so that the total expense for the first year would be something like 
 $4,500. But the inspectors' service is complicated by the matter of 
 prosecution. Much of the time of inspectors would be taken in the 
 prosecution of the owners of neglected premises. Moreover, the health 
 officer has found during the summer of 1908, in his prosecution of the 
 owners or managers of insanitary restaurants, that his inspectors were 
 practically sworn out of court by the multiplicity of opposing evi- 
 dence. This means that it will be necessary in such cases to send two 
 inspectors together in all cases, so that the testimony of one may be 
 supported by the testimony of the other. This, perhaps, would double 
 the number of necessary inspectors, making the expense of the service 
 something over $9,000. It is reasonably safe to state, however, that 
 
34 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 with such an expense for competent service, or perhaps with a slightly 
 added expense, the typhoid fly could be largely eliminated as an ele- 
 ment in the transfer of disease in the District of Columbia, and the 
 difficulty which the authorities have had in locating the cause of a 
 very considerable proportion of the cases of typhoid in the District 
 for the past two or three years indicates plainly to the mind of the 
 writer that the typhoid fly is a much more important element than 
 has been supposed. It is a comforting although comparatively insig 
 nificant fact and a matter of common observation that in certain 
 sections of the city the typhoid fly has been much less numerous dur- 
 ing the past summer than in previous years. The writer is inclined 
 to attribute this to the gradual disappearance of horse stables in 
 such sections, brought about by the rapidly increasing use of motor 
 vehicles. 
 
 A significant paragraph in Mr. Xewstead's Liverpool report, re- 
 ferred to above, contains the following words : " The most strenuous 
 efforts should be made to prevent children defecating in the courts 
 and passages ; or that the parents should be compelled to remove such 
 matter immediately ; and that defecation in stable middens should be 
 strictly forbidden. The danger lies in the overwhelming attraction 
 which such fecal matter has for house flies, which later may come into 
 direct contact with man or his foodstuffs. They may, as Veeder puts 
 it, ' In a very few minutes * * * load themselves with dejections 
 from a typhoid or dysenteric patient, not as yet sick enough to be in 
 hospital or under observation, and carry the poison so taken up into 
 the very midst of the food and water ready for use at the next meal. 
 There is no long, roundabout process involved.' " 
 
 The writer has already referred to this general subject in his re- 
 marks on the depositing of excrement in the open within town or city 
 limits, but Newstead's specific reference to children reminds one that 
 in the tenement districts of the older great cities of England and other 
 parts of Europe there occur opportunities for transfer of disease 
 which, while probably less numerous in the newer cities of the United 
 States, nevertheless must still exist and be a constant danger. 
 
 We have thus shown that the typhoid or house fly is a general and 
 common carrier of pathogenic bacteria. It may carry typhoid fever, 
 Asiatic cholera, dysentery, cholera morbus, and other intestinal dis- 
 eases ; it may carry the bacilli of tuberculosis and certain eye diseases ; 
 it is everywhere present, and it is disposed of with comparative ease. 
 It is the duty of every individual to guard so far as possible against 
 the occurrence of flies upon his premises. It is the duty of every com- 
 munity, through its board of health, to spend money in the warfare 
 against this enemy of mankind. This duty is as pronounced as though 
 the community were attacked by bands of ravenous wolves. 
 
THE TYPHOID FLY, OR HOUSE FLY. 35 
 
 As a matter of fact, large sums of money are spent annually in the 
 protection of property in the United States. Large sums of money 
 are spent also in health matters; but the expenditure for protection 
 from flies is very small and is misdirected. There is much justifica- 
 tion for the following criticism published editorially in the Journal 
 of the American Medical Association for August 22, 1908, under the 
 caption, " National Farm Commission and Rural Sanitation :" 
 
 "The President calls attention to the fact that all efforts to aid the 
 farmers have hitherto been directed to improving their material 
 welfare, while the man himself and his family have been neglected. 
 Nowhere is this more marked than in the attitude of the General 
 Government in matters relating to sanitation. It is a trite saying 
 that whereas the Government, through the Department of Agricul- 
 ture, aids the farmer generously in caring for the health of his hogs, 
 sheep, etc., it does nothing for his own health. The Government 
 issues notices to the farmer of the injury done to his crops by the 
 cotton-boll weevil and the potato bugs and how to combat them, but 
 the injury the mosquito does in spreading malaria to the people who 
 pick the cotton and hoe the potatoes is not impressed on him. The 
 fact that horseflies may carry anthrax to his cattle is dealt with at 
 considerable length, but the diseases which the house fly spreads to 
 the milk and to the farmer's family attract practically no attention. 
 How to build a hogpen or a sanitary barn is the subject of a number 
 of government publications, but how to build a sanitary privy which 
 will prevent the spread of typhoid, hook worm, and many other dis- 
 eases is regarded as of strictly local interest." 
 
 But this criticism is not entirely justified, since there was published 
 by the Bureau of Entomology of the United States Department of 
 Agriculture, in 1900, a Farmers' Bulletin, entitled " How Insects 
 Affect Health in Rural Districts," a in which all of these points men- 
 tioned by the editor of the Journal of the American Medical Asso- 
 ciation have been touched upon, and at the date of present writing 
 192,000 copies of this bulletin have been distributed among the 
 people. Moreover, a number of years ago a circular h was published 
 on the subject of the house fly, calling attention to its dangers and 
 giving instructions such as are covered in a general way in this 
 article, and some 18,000 copies of this circular have also been dis- 
 tributed. This is an indication that the General Government is by 
 no means blind to the people's needs in such matters as we have 
 under consideration, but further work should be done. That the 
 English Government is awaking to the same need is shown by the 
 fact that, in the parliamentary vote of the present year in aid of 
 
 a Farmers' Bulletin No. 155. 
 
 6 Circular No. 35, Bureau of Entomology, 1891, afterwards reissued in revised 
 form as Circular No. 71. 
 
3G LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 scientific investigations concerning disease, one of the projects sup- 
 ported by the General Government was the investigation of Doctors 
 Copeman and Nuttall on flies as carriers of disease. 
 
 A leading editorial in an afternoon paper of the city of Washing- 
 ton, of October 20, 1908, bears the heading, " Typhoid a National 
 Scourge," arguing that it is to-day as great a scourge as tuberculosis. 
 The editorial writer might equally well have used the heading " Ty- 
 phoid a National Reproach," or perhaps even " Typhoid a National 
 Crime," since it is an absolutely preventable disease. And as for the 
 typhoid fly, that a creature born in indescribable filth and absolutely 
 swarming with disease germs should practically be invited to mul- 
 tiply unchecked, even in great centers of population, is surely nothing 
 less than criminal. 
 
 ENDEMIC DISEASE AS AFFECTING THE PROGRESS OF NATIONS. 
 
 In referring to the spread of malaria in Greece, the relation of this 
 disease to the rise and fall of national power has been touched upon 
 in an earlier paragraph of this bulletin (p. 9). The subject is one of 
 the widest importance and deserves a more extended consideration. 
 
 The following paragraphs are quoted from Ronald Ross's address 
 on Malaria in Greece, delivered before the Oxford Medical Society, 
 November 29, 1906: 
 
 " Now, what must be the effect of this ubiquitous and everlasting 
 incubus of disease on the people of modern Greece? Remember that 
 the malady is essentially one of infancy among the native population. 
 Infecting the child one or two years after birth, it persecutes him 
 until puberty with a long succession of febrile attacks, accompanied 
 by much splenomegaly and anaemia. Imagine the effect it would 
 produce upon our own children here in Britain. It is true that our 
 children suffer from many complaints — scarlatina, measles, whoop- 
 ing cough — but these are of brief duration and transient. But now 
 add to these, in imagination, a malady which lasts for years, and may 
 sometimes attack every child in a village. What would be the 
 effect upon our population — especially our rural population — upon 
 their numbers and upon the health and vigour of the survivors? It 
 must be enormous in Greece. People often seem to think that such a 
 plague strengthens a race by killing off the weaker individuals ; but 
 this view rests upon the unproven assumption that it is really the 
 weaker children which can not survive. On the contrary, experience 
 seems to show that it is the stronger blood which suffers most — the 
 fair, northern blood which nature attempts constantly to pour into 
 the southern lands. If this be true, the effect of malaria will be 
 constantly to resist the invigorating influx which nature has provided ; 
 and there are many facts in the history of India, Italy, and Africa 
 which could be brought forward in support of this hypothesis. 
 
ENDEMIC DISEASE AFFECTING PROGRESS OF NATIONS. 37 
 
 " We now come face to face with that profoundly interesting 
 subject, the political, economical, and historical significance of this 
 great disease. We know that malaria must have existed in Greece 
 ever since the time of Hippocrates, about 400 B. C. What effect 
 has it had on the life of the country? In prehistoric times Greece 
 was certainly peopled by successive wave- of Aryan invaders from the 
 north — probably a fair-haired people — who made it what it became, 
 who conquered Persia and Egypt, and who created the sciences, 
 arts, and philosophies which we are only developing further to- 
 day. That race reached its climax of development at the time of 
 Pericles. Those great and beautiful valleys were thickly peopled 
 by a civilization which in some ways has not been excelled. 
 Everywhere there were cities, temples, oracles, arts, philosophies, 
 and a population vigorous and well trained in arms. Lake Kopais, 
 now almost deserted, was surrounded by towns whose massive works 
 remain to this day. Suddenly, however, a blight fell over all. Was 
 it due to internecine conflict or to foreign conquest? Scarcely: for 
 history shows that war burns and ravages, but does not annihilate. 
 Thebes was thrice destroyed, but thrice rebuilt. Or was it due to 
 some cause, entering furtively and gradually sapping away the 
 energies of the race by attacking the rural population, by slaying 
 the new-born infant, by seizing the ri>ing generation, and especially 
 by killing out the fair-haired descendant of the original settlers, 
 leaving behind chiefly the more immunised and darker children of 
 their captives, won by the sword from Asia and Africa ? * * * 
 
 " I can not imagine Lake Kopais, in its present highly malarious 
 condition, to have been thickly peopled by a vigorous race; nor, on 
 looking at those wonderful figured tombstones at Athens, can I 
 imagine that the healthy and powerful people represented upon 
 them could have ever passed through the ana?mic and splenomegalous 
 infancy (to coin a word) caused by widespread malaria. Well, I 
 venture only to suggest the hypothesis, and must leave it to scholars 
 for confirmation or rejection. Of one thing I am confident, that 
 causes such as malaria, dysentery, and intestinal entozoa must have 
 modified history to a much greater extent than we conceive. Our 
 historians and economists do not seem even to have considered the 
 matter. It is true that they speak of epidemic diseases, but the 
 endemic diseases are really those of the greatest importance. * * * 
 
 " The whole life of Greece must suffer from this weight, which 
 crushes its rural energies. Where the children suffer so much, how 
 can the country create that fresh blood which keeps a nation } T oung? 
 But for a hamlet here and there, those famous valleys are deserted. 
 I saw from a spur of Helikon the sun setting upon Parnassus, Apollo 
 sinking, as he was wont to do. towards his own fane at Delphi, and 
 pouring a flood of light over the great Kopaik Plain. But it seemed 
 
38 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 that he was the only inhabitant of it. There was nothing there. 
 'Who,' said a rich Greek to me, 'would think of going to live in 
 such a place as that? ' I doubt much whether it is the Turk who 
 ha- done all this. I think it is very largely the malaria." 
 
 In considering carefully this suggestive argument of Major Ross 
 does it not appear to indicate the tremendous influence that the 
 prevalence of endemic disease must exert upon the progress of mod- 
 ern nations, and does it not bring the thought that those nations that 
 are most advanced in sanitary science and preventive medicine will, 
 other things being equal, assume the lead in the world's work ? Who 
 can estimate the influence, of the sanitary laws of the Hebrew scrip- 
 tures upon the extraordinary persistence of that race through cen- 
 turies of European oppression — centuries full of plague years and 
 of terrible mortality from preventable disease? And what more 
 striking example can be advanced of the effect of an enlightened 
 and scientifically careful attention to the most recent advances of 
 preventive medicine upon the progress of nations than the mortality 
 statistics of the Japanese armies in the recent Russo-Japanese war as 
 compared with the corresponding statistics for the British army 
 during the Boer war immediately preceding, or for the American 
 Army during the Spanish war at a somewhat earlier date? 
 
 The consideration of these elements of national progress has been 
 neglected by historians, but they are nevertheless of deep-reaching 
 importance and must attract immediate attention in this age of 
 advanced civilization. The world has entered the historical age 
 when national greatness and national decay will be based on physical 
 rather than moral conditions, and it is vitally incumbent upon na- 
 tions to use every possible effort and every possible means to check 
 physical deterioration. 
 
INDEX 
 
 Page. 
 Abattoirs, regulations to avoid house flies 32 
 
 Anopheles mosquitoes (see also Mosquitoes, malaria). 
 
 disseminators of malaria 7 
 
 suppression in Panama 22 
 
 Ash pits containing fermenting material, breeding places of house fly 31 
 
 Bacilli, typhoid, longevity in milk, cream, butter, and cheese 27 
 
 Bacillus icteroides, not proven to be causative germ of yellow fever 19 
 
 Bacteria from flies, census 29-30 
 
 in milk, sources 28-30 
 
 Bedbug, a carrier of disease 7 
 
 Bedding, old, in ash pits, breeding place of house fly 31 
 
 Bubonic plague, conveyance by fleas 7 
 
 Cafes, regulation to avoid house flies 33 
 
 Carcasses of animals, breeding places of house fly 32 
 
 Cholera, Asiatic, carriage by house fly 7,27,34 
 
 infantum, carriage by house fly 29 
 
 morbus, carriage by house fly 34 
 
 Culcr fasciatus= Stcgomyia calopus 19 
 
 Deaths from malaria in United States 9-10 
 
 typhoid fever in concentration camps, U. S. Army 24-25 
 
 yellow fever in United States 18,31 
 
 Disease, endemic, as affecting progress of nations 36-38 
 
 Diseases, intestinal, dissemination by house fly 7 
 
 Dysentery, summer, carriage by house fly 27,34 
 
 tropical, carriage by house fly ». 27,34 
 
 Endemic disease as affecting progress of nations 36-38 
 
 Excrement, human, breeding place of house fly 31 
 
 Eye diseases, carriage by house fly 34 
 
 Fermenting animal and vegetable material, breeding placed of house fly 31-32 
 
 Filariasis, transmission by a mosquito 7 
 
 Fleas, conveyors of bubonic plague 7 
 
 Flies, biting, carriers of sleeping sickness 7 
 
 Fly, house, breeding places 31-32 
 
 disseminator of cholera, Asiatic 7, 27, 34 
 
 infantum 29 
 
 morbus * 34 
 
 dysentery, summer 27,34 
 
 tropical 27 
 
 eye diseases 34 
 
 intestinal diseases 7,27-28 
 
 purulent ophthalmia 7 
 
 typhoid fever 7 
 
 tuberculosis 7, 28, 34 
 
 legislation 32-36 
 
 life history 31 
 
 relation to typhoid fever 23-27 
 
 suppression feasible and all-important 30 
 
 manure, name for house fly • 23 
 
 typhoid, name for house fly 23 
 
 Garbage, breeding place of house fly 32 
 
 collection to avoid house flies 32 
 
 Hippelates flies, carriers of pink eye 7 
 
 Hog hairs, refuse, breeding place of house fly 32 
 
 Hops, spent, breeding place of house fly 31 
 
 Insects affecting health, publications by Bureau of Entomology 35 
 
 Lunch rooms, regulation, to avoid house flies 33 
 
 Malaria, deaths in United States 9-10 
 
 dissemination by mosquitoes 7,8-17 
 
 eradication at Ismailia, Suez Canal 16-17 
 
 in Greece 36-38 
 
 39 
 
40 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
 
 Page. 
 
 Malaria, in Italy, loss therefrom 11-12 
 
 Mauritius 11 
 
 Reunion 11 
 
 United States, history 9 
 
 loss in United States 9-14 
 
 Italy 11-12 
 
 mosquitoes. (See iVsophclrg mosquitoes and Mosquito, malaria.) 
 
 prevention 14_17 
 
 relation to agriculture and other industries of the South 13-14 
 
 suppression in Havana 17 
 
 Panama 21-23 
 
 Selar.gor, Federated Malay States 15-16 
 
 Manure, disposal, to avoid house flies 32-33 
 
 horse, breeding place of house fly 31 
 
 rabbit, in ash pits, breeding place of house fly 31 
 
 Markets, regulation, to avoid house flies 33 
 
 Milk, sources of bacteria therein :> :;<> 
 
 Mosquito, disseminator of filariasis 7 
 
 malaria 7 
 
 yellow fever 7 
 
 malaria (see also Anopheles mosquitoes i . 
 
 suppression measures 15-17 
 
 yellow fever, suppression measures 19-23 
 
 Mosquitoes, losses in general which they occasion 8 
 
 through malaria which they occasion S-17 
 
 yellow fever which they occasion 17-21 
 
 suppression in Panama 21-23 
 
 Nations, endemic disease as affecting progress 30-38 
 
 Ophthalmia, purulent, carriage by house fly 7 
 
 Paper, old, breeding place of house fly 31 
 
 Pink eye, carriage by Hippelates flies 7 
 
 Plague, bubonic. [See Bubonic plague.) 
 
 Poultry-house bedding, breeding place of house fly .".2 
 
 Progress of nations as affected by endemic disease 30-38 
 
 Hags, old. in ash pits, breeding place of house fly 31 
 
 Restaurants, regulation, to avoid house flies 33 
 
 Sanitation, rural, necessity for government support 35 
 
 Slaughtered cattle paunches, breeding places of house fly 32 
 
 Sleeping sickness, carriage by biting flies 7 
 
 " Spotted fever," carriage by tick 7 
 
 Stable inspection against house flies, probable cost 33-34 
 
 Stables, regulation, to avoid house flies 32-33 
 
 st< gomyia calopus (see also Mosquito, yellow fever). 
 
 disseminator of yellow fever 7, 19, 20 
 
 Stores, regulation, to avoid house flies 33 
 
 Straw, old, in ash pits, breeding place of house fly 31 
 
 Tallow vats, breeding places of house fly 32 
 
 Tick, carrier of "spotted fever" 7 
 
 Tuberculosis, dissemination by house fly 7,28,34 
 
 Typhoid fever, a "National Reproach" 36 
 
 dissemination by house fly 7, 23—27, 34 
 
 in concentration camps, U. S. Army 24-25 
 
 loss in United States 30 
 
 Vegetable refuse, fermenting, breeding place of house fly 32 
 
 Yellow fever, cause, history of investigation 19 
 
 deaths in New Orleans 21 
 
 United States '_ 18 
 
 dissemination by mosquito 7 
 
 history in America 17-18 
 
 loss in United States 18 
 
 mosquito. (See Mosquito, yellow fever.) 
 
 suppression in Havana and New Orleans 10-21 
 
 Panama 21-23 
 
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