Pertussis underdiagnosed; adult booster-vaccine prevents "whoop" & infant deaths

This gentleman (not pictured in the photo) graciously allowed himself to be videotaped in the midst of a severe whooping cough episode caused by Bordetella pertussis; the video is posted on the New England Journal's website. He had not been vaccinated: vaccination during childhood greatly reduces the risk of severe or life-threatening pertussis infection, and reduces cough (typically eliminating any "whooping") if infection does occur. However, immunity after pertussis vaccination wanes throughout life; pertussis infection during adulthood in previously immunized people is common, usually undiagnosed, and an under-recognized public health problem.

Pertussis infection in previously immunized adults manifests with milder symptoms initially indistinguishable from the common cold, but with non-resolving cough that may last for weeks. While pertussis is rarely serious for the infected adult, unknowingly infected adults can transmit life-threatening pertussis infections to less-than-fully vaccinated infants. For this reason, the CDC advises all adults receive a booster immunization for pertussis.

Diagnosis of pertussis is by PCR and/or culture of a nasopharyngeal swab ideally collected within the 1st 3 weeks of illness onset, when bacterial DNA is most abundantly present. Testing sensitivity plummets after the 4th week of cough, or after antibiotics active against pertussis have been given, either of which cause bacterial DNA to disappear and the risk of a false negative test to increase. The same swab specimen can be used for both PCR and culture testing.

Macrolide antibiotics (erythromycin, azithromycin, or clarithromycin) are curative, and in practice are probably often given empirically while waiting for test results. Bactrim is an alternative treatment.

"Whooping Cough in an Adult," NEJM video online, 2012;366:e39.

Recommended antimicrobial agents for the prevention and postexposure prophylaxis of pertussis. 2005 CDC guidelines. MMWR 2005;54:1-16.

CDC website, "Pertussis (Whooping Cough)"