key: cord-0040671-nxhto48t
authors: Plank, Rebeca M.
title: Foreign Travel: Immunizations and Infections
date: 2009-12-16
journal: Decision Making in Medicine
DOI: 10.1016/b978-0-323-04107-2.50109-5
sha: 38939fac66449f2a7927f543b606ab55170bbb04
doc_id: 40671
cord_uid: nxhto48t

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A. Two questions must be asked in the initial evaluation of a traveler: What is the patient's health status, and where will he or she travel? Variables to consider include countries to be visited, whether travel will be rural or urban, planned activities, and duration of visit.

It is important to remember that persons returning to visit their country of origin after living in the United States are also at risk for endemic infections, sometimes more so because they may not feel the need to take special precautions. B. Infections are acquired through exposure to contaminated food and water, exposure to vectors, such as ticks and mosquitoes, and person-to-person transmission. Travelers should be advised to practice strict hand hygiene and to avoid uncooked food and food from street vendors. They should consume only bottled beverages and use bottled water for ice cubes and for brushing teeth, etc. Fresh water exposure (adventure travel) is a potential source of infections, such as schistosomiasis and leptospirosis. Sexually transmitted diseases, including HIV, are always a risk and travelers should be advised to abstain from sex or to use condoms for all encounters. Travelers should also consider carrying sterile needles and syringes with them in case of medical emergency. C. One of the fi rst things to be ascertained is that the traveler is up to date with the standard Centers for Disease Control and Prevention (CDC) vaccination schedule for children and adults; this includes pneumococcus, infl uenza, tetanus, and measle/mumps/rubella (MMR) vaccines because these infections have been acquired overseas. All overseas travelers should be encouraged to be vaccinated against hepatitis A, hepatitis B, polio, and typhoid. Yellow fever occurs only in sub-Saharan Africa and tropical South America, and many countries in these regions require proof of vaccination for entry. A meningitis vaccine is recommended for those traveling to areas in the meningitis belt across central Africa, and

Saudi Arabia requires that Hajj and Umrah visitors have a certifi cate of vaccination. For those who will be traveling to areas where rabies is relatively common but the immune globulin and vaccine would not be immediately available (e.g., trekkers), preexposure vaccination should be considered. Japanese encephalitis vaccine may be indicated in some cases for travelers to Southeast Asia. The cholera vaccine is currently not recommended. D. Malaria prevention should be a comprehensive endeavor, including remaining in screened areas when possible and using a mosquito net at night, minimizing skin exposure to mosquitos, using insect repellents, and chemoprophylaxis with Malarone (atovaquoneproguanil), doxycycline, or mefl oquine. Mefl oquine has the advantage of requiring a weekly (rather than daily) dose but has the not uncommon downside of neuropsychiatric side effects. As a result of the emergence of chloroquine resistance, chloroquine prophylaxis is useful only for travelers going to the Caribbean and Central America north of the Panama Canal. Appropriate antimalaria precautions will also protect a traveler from other mosquito and tick-borne illnesses, such as dengue and rickettsial illnesses. E. Diarrhea is the most common illness in travelers. The importance of adequate hydration in such cases should be emphasized. Increasing resistance to fl uoroquinolones limits their usefulness in parts of Asia where azithromycin is recommended. Patients should be given at least a 3-day supply of antibiotics to take with them and instructed to take them in case of moderate to severe diarrhea with fever or pus, mucus, or blood in the stool. If treatment is initiated promptly, even a single dose may reduce the duration of the illness to a few hours. Pepto-Bismol taken every 30 minutes for eight doses has also been shown to decrease stool frequency and shorten illness duration. F. If a traveler returns with a nonspecifi c febrile illness, things that are life threatening, transmissible, or treatable must be excluded immediately. Malaria must be investigated (regardless of prophylaxis history) through thick and thin blood smears. If malaria parasites are seen on smear but no speciation is possible, treatment should be targeted to Plasmodium falciparum, which is the most virulent species, and should be assumed to be drug resistant. The incubation period for malaria can be as short as 1 week and as long as several months (even years). Blood cultures for typhoid should be obtained (regardless of vaccination status). Typhoid fever may or may not include GI symptoms. Suspicion for a highly contagious and morbid illness, such as a hemorrhagic fever or the recent severe acute respiratory syndrome (SARS), in patients with compatible symptoms and returning from affected areas should be reported to local health departments immediately. G. Once investigation is under way for malaria and typhoid, further clinical investigation should be dictated by history (e.g., contact with fresh water, recent unprotected sexual activity) and localizing signs and symptoms (e.g., diarrhea, cough, rash). Dengue is common in travelers and although it causes much discomfort is generally self-limited. Dengue hemorrhagic fever, manifesting with plasma leakage, platelets Ͻ100,000 per ml, fever lasting 2-7 days, hemorrhagic tendency, and possibly the development of shock, is generally limited to individuals experiencing repeat dengue infection and treatment is supportive.

The CDC maintains a website containing updated information about regional outbreaks that can also help guide workup. H. If a patient returns with diarrhea, stool should be sent for culture (Escherichia coli, Salmonella, Shigella, Campylobacter) and ova and parasite (O&P) three times. Respiratory symptoms may result from viral infections and should be evaluated in much the same way as for nontravelers. Because tuberculosis (TB) is rarely acquired by short-term travelers, it should be more seriously considered in those having been abroad for months or years and an acid-fast bacillus (AFB) smear should be done. Domestic infections should also be considered (e.g., urinary tract infection [UTI] , upper respiratory infection [URI]). I. A partial list of illnesses that can be seen in returning travelers is provided in the algorithm; when in doubt, patients should be referred to a specialized travel clinic and sometimes to an emergency department. See also the useful websites listed in the references.

Health advice and immunizations for travelers

Illness after international travel