One place I look for info on this and other health topics like immunizations is the US Center for Disease Control web site:
http://www.cdc.gov
It seems like some of their links also then point at the World Health Organization:
http://www.who.int
I would agree with other posters that what we've seen so far puts it far down on my worry list, but useful to check some of those official sites out for questions or concerns. The other travel site I sometimes look at is
http://travel.state.gov