Gram Negative Coccobacilli
A 2 yr old child is brought by parents with history of cough with characteristic inspiratory whoop. The child is not immunizeD. Which of the following would be the best method of diagnosis? (AIPG 2011)
|A||“Cough plate” culture|
a. Nasopharyngeal cultures in untreated pertussis remain positive for a mean of 3 weeks after the onset of illness; these cultures become negative within 5 days of the institution of appropriate antimicrobial therapy.
b. The duration of a positive PCR in untreated pertussis or after therapy is not known but exceeds that of positive cultures. Since much of the period during which the organism can be recovered from the nasopharynx falls into the catarrhal phase, when the etiology of the infection is not suspected, there is only a small window of opportunity for culture-proven diagnosis.