Snapshot A 40-year-old man presents to the primary care physician after 3 weeks of a dry cough. He reports that he occasionally vomits after an episode of coughing and he hears “whoops” during some episodes. His childhood immunization history is incomplete, and the patient states not having had any immunizations in the past 20 years. A special nasopharyngeal swab is sent for analysis and antibiotics are given. Introduction Classification Bordetella pertussis a gram - aerobic coccobacilli transmission respiratory droplets Associated conditions whooping cough 100-day cough Prevention DTaP vaccine vaccine against diphtheria, tetanus, and pertussis acellular pertussis vaccine 5 doses before school-age, completed by 4-6 years of age Tdap vaccine booster vaccine at 11-12 years of age should also be given to pregnant mothers and those around them Epidemiology Demographics infants are especially at risk < 6 months of age too young to be vaccinated unvaccinated children Risk factors exposure to infected people incomplete vaccination HIV exposure ETIOLOGY Pathogenesis bacteria colonizes mucosal surface pertussis toxin binds to and activates adenylate cyclase by inhibiting Gi impairs phagocytosis, allowing the bacteria to survive tracheal cytotoxin impairs cilia, preventing normal clearance of respiratory secretions low lung volume at the beginning of inspiration causes strong inspiration and inspiratory “whoop” Presentation Symptoms catarrhal stage (first) low-grade fevers coryza paroxysmal stage (second) dry cough and whoop post-tussive vomiting convalescent stage (third) recovery Physical exam whooping cough in children dry cough on expiration “whoop” on inspiration 100-day cough in adults post-tussive vomiting paroxysmal cough Differential Mycoplasma pneumonia distinguishing factor also presents with a dry cough, but no whooping cough and no posttussive vomiting Treatment Management approach infected patients should avoid exposure to vulnerable populations exposed patients should still be treated Medical macrolides indication first-line therapy drugs azithromycin clarithromycin erythromycin trimethoprim-sulfamethoxazole indication allergies to macrolides Complications Pneumonia Failure to thrive Death especially in young infants Apnea especially in young infants Prognosis Can be fatal in infants