What is the optimal specimen type for recovering Bordetella pertussis?

What is the optimal specimen type for recovering Bordetella pertussis?

• A. Anterior nares swab
• B. Blood
• C. Expectorated sputum
• D. Nasopharyngeal swab

Answer: (D)

Bordetella pertussis is most reliably recovered from the nasopharynx because this bacterium colonizes the mucosa there and is shed in that region early in the illness. A nasopharyngeal swab (or aspiration) from the posterior nasopharynx captures the highest bacterial load, making culture and PCR testing most sensitive. Anterior nares swabs sample a much smaller, more superficial area and miss many organisms; blood would not contain the organism, and expectorated sputum is uncommon in pertussis and can be contaminated and less reliable. Therefore, a nasopharyngeal specimen collected properly provides the best chance to detect Bordetella pertussis. Collecting the sample early in the disease course and before antibiotics further improves yield.

Bordetella pertussis is most reliably recovered from the nasopharynx because this bacterium colonizes the mucosa there and is shed in that region early in the illness. A nasopharyngeal swab (or aspiration) from the posterior nasopharynx captures the highest bacterial load, making culture and PCR testing most sensitive. Anterior nares swabs sample a much smaller, more superficial area and miss many organisms; blood would not contain the organism, and expectorated sputum is uncommon in pertussis and can be contaminated and less reliable. Therefore, a nasopharyngeal specimen collected properly provides the best chance to detect Bordetella pertussis. Collecting the sample early in the disease course and before antibiotics further improves yield.