Nasopharyngeal culture is commonly performed to detect carrier states of which organism?

• A. Neisseria meningitidis
• B. Corynebacterium diphtheriae
• C. Streptococcus pyogenes
• D. Haemophilus influenzae

Answer: (A)

The main idea is identifying asymptomatic carriers who harbor a pathogen in the nasopharynx and can transmit it to others. Neisseria meningitidis is well known for colonizing the nasopharynx in people who have no symptoms, making nasopharyngeal culture a common method to detect carrier states. Detecting meningococcal carriage is important for public health so close contacts can be monitored or given prophylaxis to prevent outbreaks of meningitis and septicemia. The other organisms listed can be found in the nasopharynx or throat, but they are not classically sought as carriers in routine nasopharyngeal culture screens in the same way; their relevance is usually tied to symptomatic disease (diphtheria, pharyngitis, etc.).