Pertussis and notifiable disease statistics

[Marnica]

I am so tired of reading sensationalized media strories about the WC outbreak in California and how it is due to too many people not being vaccinated.

Here is the latest one I've found
http://www.allvoices.com/contributed...ion-debate?r=1

Here is where I get annoyed.
It states nearly 1500 Californians have been diagnosed with WC. It says nothing about these cases being confirmed by laboratory report or not and it says nothing of vaccination status. And it, of course blames the unvaccinated or those not up to date on boosters for blowing herd immunity. Never mind that it doesn't even really exsist with htis vaccine

When I checked the DPH website for California it says there have been 2,492 cases reported (again no mention of confirmation)
http://www.cdph.ca.gov/programs/immu...%20Release.pdf
Are we to assume that any reported case has been confirmed with a laboratory test?

Then I looked at the MMWR this week for California and it reports 809 cases for the entire year. In fact there have been 1,481 cases in TX in 2010, yet we aren't hearing anything about their epidemic. hmmmm

There is so much disparity in statistics. I would not trust any number reported in a newspaper. I know from first hand experience that what is reporetd in the media is often inaccurate and/or distorted. But there is a huge difference between 2492 cases and 809 cases.

[amnesiac]

It might be of interest to know how health departments classify what criteria make something a case: http://www.cdph.ca.gov/programs/immu...ion_8_2010.pdf

Also, keep in mind that cases are not entered into the electronic reporting system in real time so more accurate short term numbers are going to come more locally rather than from the CDC. A health department might receive & investigate cases that don't get to the CDC for weeks-months.

I think the reason this has become such a news item has to do with the number of fatalities - consider that in 2009 Texas had half the number of fatalities out of a whole heck of a lot more cases. Also of interest is that a particular region of Texas shows a much greater incidence rate but this is most likely due to a survellance glitch (slide 16):
http://cdc.confex.com/cdc/nic2010/we...aper22804.html