infections
Pertussis
Diagnosis of Pertussis
Culture of a sample of mucus Sometimes other tests on a mucus sample Doctors suspect pertussis because of the typical whooping cough or other symptoms. They confirm the diagnosis by culturing a sample of mucus from the back of the nose or throat. In people with pertussis, culture results are usually positive during the first two stages of illness but often are negative after several weeks of illness. Results from culture may take up to 7 days. Polymerase chain reaction (PCR) testing, done on samples from the nose or throat, is the most useful test. It increases the amount of the bacteria's DNA so that the bacteria can be detected more quickly and identified more easily. 