How can a traveler be informed of any communicable disease outbreaks in the region one is traveling to? (or the city one is in). Is there an app/radio station that keeps a track of these outbreaks? Does an international CDC (Centre for Disease Control) exist, which keeps a track of outbreaks across the world?
There are several!
The CDC actually monitors worldwide as well as other groups (World Health Organisation, for example).
The WHO has a GAR (Global Alert and Response) page which coverts, alerts, outbreaks and news on diseases in countries worldwide.
If you want something less...dry, you may like the Global Incident Map of outbreaks. It's one of the easiest to tell at a glance if there's something in your region of choice.
Healthmap is similar, but not as detailed.
And of course you should always just keep an eye on your own country's travel alerts. For example, Australia has their Travel Advisory Alerts page.
I assume from your profile that you're in the USA (on a global site, it's really not very helpful to just say "Location: Bham"). In that case, the State Department has a page of Travel Warnings and Alerts. Warnings are for long-term problems; Alerts for typically short-term issues, including disease outbreaks.