Tuesday, February 11, 2014

These things are cyclical: the Olympics, fashion, and whooping cough

Whooping cough (in doctor-speak pertussis, caused by the bacterium Bordetella pertussis) is akin to presidential elections, fashion, and the Winter Olympics.

All are cyclical.

But while campaign schedules and the winter games follow a clear and predictable pattern (no one was taken by surprise when the Sochi games kicked off last week), fashion and whooping cough are a little less attached to the Gregorian calendar.

Fashion tends to follow relatively long cycles-- after all, most of us had to recover from the trauma of the '80s before hairspray and leggings showed up again in our closets. Rest assured, traumatized and recovered people, Juno Mars' Superbowl half-time show last week confirmed that the '80s are back.

Whooping cough cycles every 3-5 years
Whooping cough gives us less recovery time because it tends to emerge and submerge in cycles every three to five years.

Weird, right?!

It's not really understood why this is; the cycling probably has to do with a combination of something called herd immunity, parts of the actual bacteria life cycle, and some evil wizardry of nature.

The last bad cycle of whooping cough in California was in 2010.

In California in 2010, there were more than 9,100 documented (laboratory-confirmed) cases of whooping cough.  This was more cases than had EVER been reported in the vaccine era (The whooping cough vaccine came out in the 1940s). It can be assumed that there were many more thousand undocumented cases because many people with the disease don't actually get tested. Of these confirmed cases, 83% were in children under 18. That year, 10 California infants died of whooping cough. All infants were under three months of age, and most were under two months. Nine out of ten were Latinos. One of my wonderful residency classmates was involved in the care of one of those infants here in Sonoma County.

After that peak in 2010, California cases went down:
3,011 total cases in 2011
1,022 total cases in 2012
. . . but now cases seem to be increasing again:
2,372 cases in 2013.

For those Californians paying any attention, whooping cough may be coming baaaaack. Almost predictably so.

And the worst news of all? This week the California Department of Public Health announced the death of a 2 month old infant (the baby first got sick at 4 weeks of age). That's the first whooping cough infant death in California since the 2010 epidemic.

And that worries me-- and I'm thinking it should worry you as well.

What are the signs and symptoms of whooping cough?
You see, whooping cough is a pretty challenging diagnosis to make. In adults, whooping cough initially presents as a pretty mild respiratory illness, looking uncannily like the common cold.

Imagine this scenario: healthy adult comes to see her primary care provider with a few days of runny nose, low grade fever, and an intermittent cough. Astute clinician listens to her patient's lungs, checks her throat and her ears, feels reassured by no obvious bacterial infection (e.g. pneumonia, ear infection) and sends her on her way with recommendations about increasing fluids, considering zinc, vitamin C, honey and a few days of rest.