There's a site called Healthmap.org which contains alerts by country which can be useful. The best way of using it I find is to scroll down to "Alerts by country" in the left hand menu and then click the "A-Z" button to sort countries alphabetically. Then click the country you're interested in which will cause the map to jump to that region. From there, click a red, orange, or yellow balloon to get the links to diseases currently affecting a particular area.
Here's the URL to the site: http://healthmap.org/en
[ Edit: Edited on 21-Apr-2009, at 00:58 by Blinq ]