Like it or not, sickness often infects you and your friends. if a handful of people you know have the flu, chances are pretty high that you’ll come down with it too. it was inevitable, then, for the social side of illness tracking to make its way onto the Internet.

The most obvious manifestation of social sickness tracking can be seen with Sickweather, a new startup that mines data from Twitter, Facebook, and user input to show which illnesses are going around in your local area–and in your friend group. the service explains, “just as Doppler radar scans the skies for indicators of bad weather, Sickweather scans social networks for indicators of illness.”

Eventually, Sickweather hopes to track symptom keywords (i.e. “runny nose,” and “cough”), but for now it’s focusing on simpler terms like “pneumonia” and bronchitis.” Illnesses are shown on a map, and in future versions, users will be able to track sicknesses via cell phone (new alert: stay away from Sarah, she’s super germy!).

Social sickness tracking can also be seen with Google’s Dengue Trends, a tracking tool for dengue feveroutbreaks that mines web search results from Brazil, Bolivia, India, Indonesia and Singapore to generate an early-warning system for outbreaks. Users won’t be able to see who exactly is searching for dengue fever symptoms, but they will know when an outbreak is headed their way. Google’s Flu Trends performs a similar purpose–and is probably more useful for people outside of dengue-heavy countries.

We can probably expect to see more initiatives like this in the future. Scientists recently discovered, for example, that weather forecasts can predict cholera outbreaks. so in the future, Google (or a service like HealthMap) could mash up weather predictions with symptom reports in cholera-prone areas for another kind of early warning system.

For now, though, tracking illness outbreaks via sites like Sickweather may be the simplest way to make sure you avoid coming down with a cold–or something worse.

[Image by Flickr user Svenstorm]

Reach Ariel Schwartz via Twitter or email.