An 8-year-old boy is brought to the physician because of a 7-day history of a progressively worsening cough. The cough occurs in spells and consists of around 5-10 coughs in succession. After each spell, he takes a deep, noisy breath. He has vomited occasionally following a bout of coughing. He had a runny nose for 1 week before the cough started. His immunization records are unavailable. He lives in an apartment with his father, mother, and 2-week-old sister. The mother was given a Tdap vaccination 11 years ago. The father's vaccination records are unavailable. His temperature is 37.8°C (100.0°F). Examination shows no abnormalities. His leukocyte count is 42,000/mm3. Testing of respiratory secretions shows gram-negative coccobacilli. Which of the following is most likely involved in the pathogenesis of this patient's symptoms?

Question

An 8-year-old boy is brought to the physician because of a 7-day history of a progressively worsening cough. The cough occurs in spells and consists of around 5-10 coughs in succession. After each spell, he takes a deep, noisy breath. He has vomited occasionally following a bout of coughing. He had a runny nose for 1 week before the cough started. His immunization records are unavailable. He lives in an apartment with his father, mother, and 2-week-old sister. The mother was given a Tdap vaccination 11 years ago. The father's vaccination records are unavailable. His temperature is 37.8°C (100.0°F). Examination shows no abnormalities. His leukocyte count is 42,000/mm3. Testing of respiratory secretions shows gram-negative coccobacilli.  Which of the following is most likely involved in the pathogenesis of this patient's symptoms?

Quizplus · Accepted Answer

Eductional Objective: Bordetella pertussis, a small, gram-negative coccobacillus, can cause outbreaks of whooping cough in unvaccinated individuals.  Infected infants and children generally develop mucoid rhinorrhea followed by severe, paroxysmal cough that may be associated with an inspiratory whoop and vomiting.  The bacterium is largely noninvasive and secretes several exotoxins that severely damage ciliated respiratory epithelium.

An 8-Year-Old Boy Is Brought to the Physician Because of a 7-Day