key: cord-0901420-v9ed5cjm authors: Koenig, Kristi L.; Farah, Jennifer; McDonald, Eric C.; Thihalolipavan, Sayone; Burns, Michael J. title: Pertussis: The Identify, Isolate, Inform Tool Applied to a Re-emerging Respiratory Illness date: 2018-12-05 journal: West J Emerg Med DOI: 10.5811/westjem.2018.11.40023 sha: d1312034ff2df8c47731d9519e2a4330e5cbc535 doc_id: 901420 cord_uid: v9ed5cjm Pertussis, commonly referred to as “whooping cough,” is a highly contagious acute respiratory infection that has exhibited cyclical outbreaks throughout the last century. Although vaccines have provided some immunity, many populations, including infants and pregnant women, remain at risk for serious illness. Through the use of the novel “Identify, Isolate, Inform” (3I) tool, emergency department (ED) providers can readily recognize key symptoms of the disease and risk factors for exposure, thus curbing its transmission through early initiation of antimicrobial therapy and post-exposure prophylaxis. The three classic stages of pertussis include an initial catarrhal stage, characterized by nonspecific upper respiratory infection symptoms, which may advance to the paroxysmal stage, revealing the distinctive “whooping cough.” This cough can persist for weeks to months leading into the convalescent stage. Household contacts of patients with suspected pertussis or other asymptomatic, high-risk populations (infants, pregnant women in their third trimester, and childcare workers) may benefit from post-exposure prophylactic therapy. The Pertussis 3I tool can also alert healthcare professionals to the proper respiratory droplet precautions during contact with a symptomatic patient, as well as isolation practices until antimicrobial treatment is in progress. ED personnel should then inform local public health departments of any suspected cases. All of these actions will ultimately aid public health in controlling the incidence of pertussis cases, thus ensuring the protection of the general public from this re-emerging respiratory illness. Pertussis, commonly referred to as "whooping cough," is an acute respiratory illness that is highly contagious. Bordetella pertussis, a Gram-negative bacterium, travels via respiratory droplets infecting human hosts. 1 Worldwide epidemics have occurred throughout history, prompting study and control measures, including the development of vaccines. 1 However, even in vaccinated populations, pertussis demonstrates periodic outbreaks. For example, in 2010 California experienced a large What do we already know about this issue? Pertussis, or whooping cough, a highly contagious respiratory illness, presents in cyclical outbreaks every few years. What was the research question? Investigators sought to modify the "Identify, Isolate, Inform" (3I) Tool for use in the identification and management of pertussis. What was the major finding of the study? A novel Pertussis 3I Tool is created for real-time application in managing patients presenting to the emergency department (ED). The 3I Tool aids ED providers who play an essential role in identifying and treating this vaccine-preventable disease. workers in the assessment and treatment of patients who may have pertussis (Figure) . [5] [6] [7] [8] [9] [10] After an overview of the disease and critical information pertaining to transmission and treatment, we explain and present here the Pertussis 3I tool. The presentation of pertussis varies widely, and can be affected by factors such as vaccination status and age. It is classically described as having three stages. [11] [12] [13] [14] After an initial incubation period of 7-10 days, the disease begins with the catarrhal stage, which has a duration of one to two weeks. This manifests as a mild cough with lacrimation and rhinorrhea. There may also be a low-grade fever. After the catarrhal stage, the patient may advance to the paroxysmal stage, which lasts two to four weeks. This is where the characteristic paroxysmal or "whooping cough" may occur, described as a grouping of multiple short coughs followed by a single, forceful inspiratory "whoop." An audio example of this signature cough is available here: http://www.pkids.org/diseases/pertussis.html. This cough may be associated with emesis, cyanosis or even apnea. 15 The third or convalescent stage is characterized by a persistent cough that can last from four weeks up to several months. This is why pertussis is known as the "100-day cough" in China. 16 Older children, adolescents, and adults may report a nonproductive cough that is worse at night or feelings of a choking sensation. They likely will be asymptomatic between coughing episodes. 11 Presenting symptoms may be nonspecific in both infants and older patients. Young infants may initially be afebrile with mild symptoms that rapidly progress to respiratory distress/apnea, hypoxia or seizures. 12 Unvaccinated individuals, or those who have not yet completed the vaccine series, are the most at risk. This includes infants two months of age, trimethoprim/ sulfamethoxazole is recommended. 19, 23, 24 PEP is limited to certain groups (Table) . 25 These include household contacts of a pertussis case and high-risk populations. With regard to household exposures, even if these contacts are asymptomatic and/or current with immunizations, it is recommended they receive antimicrobial treatment within 21 days of cough onset in the index patient. High-risk groups include infants, women in their third trimester of pregnancy, caregivers or household contacts of infants, and anyone who works in or attends a childcare setting. 25 Antibiotic selection and duration of treatment for either PEP or a confirmed case of pertussis are identical. Depending on the patient's age and therapy of choice, treatment includes a 5-14 day course of a macrolide, with the treatment duration dependent on the macrolide chosen. In cases of PEP, treatment should be initiated within 21 days of exposure. 19, 23 Disposition Although dependent on provider judgment, patients with mild to moderate disease can be safely discharged home to undergo antibiotic treatment, with careful attention noted to household contacts or other possibly exposed individuals. Hospital admission is recommended for neonates because they are at risk for apnea. 19 Additionally, admission is recommended for patients