Grown-ups: A Forgotten but Crucial Cause for the Pertussis Epidemic

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August 4, 2012

Finally, the media seems to be taking note of the terrible pertussis (whooping cough) outbreaks around the country. I’m relieved to see the coverage, because pertussis can kill or cause long-term complications like brain damage, particularly in infants. But I can’t say I’ve been impressed with how the issue has been handled by the press so far.

Many articles, like this one in Forbes, seem to blame the outbreaks entirely on vaccine denialists. But the fact is, vaccinated kids are getting sick too: In Skagit County, Washington, the epicenter of one of the worst outbreaks this year, less than 25 of more than 500 pertussis cases since March 2012 were in unvaccinated kids, according to Communicable Disease Manager Sandi Paciotti.

Then there’s this popular article published on Tuesday in the Washington Post, where Ezra Klein splits the blame between anti-vaxers and vaccine failure (the latter helps explain the fact that vaccinated kids are getting sick). But again, although these two factors are certainly contributing to the epidemic, I would argue that Klein has forgotten a, if not the, major driving factor.

Most adults have not gotten pertussis boosters.

According to the CDC’s latest numbers, only eight percent of American adults have gotten Tdap boosters since they became available in 2006. And even adults who were fully vaccinated against pertussis as children can and do catch pertussis, because immunity from the vaccine does not last. We don’t always see this adult vulnerability reflected in the official pertussis numbers, which suggest that kids are mainly the ones getting sick, but that’s because pertussis only causes a mild illness in adults who have previously been vaccinated. And let’s face it: how many adults who come down with a mild cough think it’s pertussis and see their doctors about it?

I think un-boostered adults are really driving the ongoing epidemic—in a way, they’re reservoirs. They’re catching pertussis, dismissing it as nothing to worry about and going untreated, and then infecting those around them for a month or longer. (A 2007 study found that at least 73 percent of babies catch pertussis from adults.) We talk about how antivaxers’ kids are crumbling herd immunity against pertussis—and yes, they are—but so are 280 million American adults, and they’re probably the far bigger problem. So please: if you haven’t already, make an appointment with your doctor or stop by a local health clinic and get your Tdap shot immediately.

References:

Wendelboe AM, Njamkepo E, Bourillon A, Floret DD, Gaudelus J, Gerber M, Grimprel E, Greenberg D, Halperin S, Liese J, Muñoz-Rivas F, Teyssou R, Guiso N, Van Rie A; Infant Pertussis Study Group. (2007). Transmission of Bordetella pertussis to young infants Pediatric Infectious Disease Journal DOI: 10.1097/01.inf.0000258699.64164.6d

Reposted with permission from Melinda Wenner Moyer's Body Politic Blog at PLOS Blogs. Read the original post here.

Photo credit: Nathan Reading via Flickr