Font Size

Whooping Cough (cont.)

Exams and Tests

The best way to diagnose whooping cough is by confirming the presence of the specific disease-causing bacteria Bordetella pertussis in mucus taken from the nose and throat.

Because the growth of the bacteria is inhibited by cotton, either calcium alginate or Dacron swabs must be used in obtaining the sample. Studies have shown that cultures are more likely to be positive if the sample is collected during the first stage of the illness or early in the second. The likelihood for isolating the organism (and confirming the diagnosis) declines with any delay in specimen collection beyond the first three weeks of illness. A culture negative for Bordetella pertussis is usually seen after five days of treatment with antibiotics.

Other laboratory methods used to diagnosis pertussis infection such as serologic testing and PCR are available in certain labs. However, neither method has been shown to be more specific than culture isolation of the organism.