Edit: No outbreak thank god- I just seen this was a 2010 article circulating like crazy.
Truthfully I did not take the time to review posts to see if this has been already posted.
Also I live in Canada, so perhaps this is already common knowledge to the Americans but I just learnt of this.
Disclaimer: I'm not starting a debate on pro/con vaccinations but just want to share this knowledge that I have recently come across.
annnd...to top it off I don't know how to make the link clicky... sorry :S *fail*
http://www.cnn.com/2010/HEALTH/10/20/california.whooping.cough/index.html