So is this the big year for pertussis?

[newmum35]

Trends Pertussis is an endemic illness. In the United States epidemics occur every 3-5 years. The most recent epidemic occurred in 2005 (25,616 reported cases). Overall increase in cases since 1990, with disproportionate increase in adolescents and adults.

http://www.cdc.gov/ncidod/dbmd/disea...ertussis_t.htm


Seeing as pertussis peaks every 3-5 years, and the last one was 2005, does this mean this year is going to be a peak year?

Checking current trends doesn't show reported cases to be too extreme (1172 so far in 2010)

http://www.cdc.gov/mmwr/PDF/wk/mm5910.pdf

2009 cases were 2322 so it certainly didn't peak last year (thought maybe they forgot to update the other page) .. it doesn't show what the 2008 totals are. Does anyone know for 2008 and 2007 what the numbers were?

[tanyalynn]

This seems so tricky. I didn't bookmark it, but I remember a page from CDC that said there are likely at least a million cases of pertussis in the US each year, have you seen that? Under-recognition seems like such a significant problem, I'm not confident we can recognize years with higher-than-normal levels of pertussis. Maybe it's possible, it just may not be as straightforward as we'd hope.

[newmum35]

No, I haven't seen that. I do realize that "reported" cases are just that - those serious enough to have seen a dr and the dr reports it to the health dept. So true numbers for all the illnesses are likely much higher. But... its a starting point and if there is a much higher # of reported cases in a given year, then we can assume other numbers are much higher too (such as the unreported cases).

[amnesiac]

Since this is about a disease rather than vaccines I'm moving to H&H.

[carmel23]

the point about under-reporting is an interesting one. This year the 'regular' cold/cough in our area was really bad--the cold had a pretty severe cough associated with it.

Our pediatrician mentioned doing more tests for pertussis, which all came back negative...

But I wonder if more doctors tested for it because the cough was worse this year?? And more tests resulted in more + tests... since there were more tests performed?

Just a thought...

[tanyalynn]

Here's a study that's interesting in terms of diagnosing pertussis...

http://pediatrics.aappublications.or...full/100/6/e10

It was a prospective study in Germany, they swabbed everyone who came in with 7+ days of coughing regardless of what the doctor thought the cause was. Vaccination rates for pertussis were really low at the time, so doctors were expecting to see WC, but just using symptoms, they weren't that great at diagnosing it. But to me, it looks more like typical pertussis is difficult to distinguish from other causes of cough, and it's mostly the extreme cases (young age or particularly severe case) that stands out clearly.

If there's any testing bias in the US--say CDC or a state health department is concerned about low vaccination rates in a particular region--then that could change the reported cases of pertussis quite a bit, if cases are often missed.

[ASusan]

And don't I recall that there was a particular pertussis test that was giving a LOT of false positives? That was about 2 - 2.5 years ago, so 2007-8ish.