Pertussis and persistent cough: practical, clinical and epidemiologic issues

Abstract

Background: Epidemiologic issues of testing, treatment, prevention, immunization, mandated reporting, and post-exposure prophylaxis do not often intrude on the Emergency Department management of the well-appearing adolescent or adult with a couple of weeks of cough.

Objectives: Considering that waning immunity to pertussis, the only vaccine-preventable disease with increasing cases and deaths in the United States, is responsible for 12-35% of such illness, such issues need to be considered.

Discussion: Mostly self-limited in adults, transmission of pertussis to infants places them at risk for hospitalization and death. Pertussis is highly contagious (80% transmission), and atypical presentations are the rule in adults (cough alone) and infants (apnea, bradycardia, poor feeding). Treatment in the first few weeks can impact the clinical course, and later treatment can still prevent transmission. Clinical features like paroxysmal cough, inspiratory "whoop," and post-tussive emesis have mildly increased predictive values and may be absent in adults. Testing is unreliable after 3 weeks of cough. Treatment reduces communicability within 5 days and is suggested without regard to test results within 3 weeks of cough onset for those aged > 1 year (within 6 weeks of cough for < 1 year). Reporting requirements are based on the clinical case definition: ([Cough ≥2 weeks] + [paroxysms OR whoop OR post-tussive emesis]). Lower reporting thresholds are appropriate during an outbreak or when vulnerable populations are at risk. Post-exposure prophylaxis is recommended for at-risk contacts. Tdap is encouraged for all adults.

Conclusion: Practical recommendations consistent with the most current guidelines are offered.