Which statement about pertussis is true?

• A. A viral infection causing a mild rash
• B. An airborne bacterial infection that affects mostly adults
• C. An airborne bacterial infection that primarily affects children under 6 years and features a 'whoop' on inspiration
• D. A fungal infection of the respiratory tract

Answer: (C)

Pertussis is a contagious bacterial infection of the respiratory tract that spreads through airborne droplets. In young children, especially those under 6 whose vaccination may be incomplete, it causes a severe, prolonged cough that often ends with a high-pitched inspiratory sound—the "whoop"—as they attempt to take in air through narrowed airways. This classic whoop helps distinguish it from other respiratory illnesses. It is not a viral infection with a rash, nor a fungal infection, and while adults can acquire it, the hallmark presentation described here in young children is why that statement is true.