"So, I'm sitting at home, I'm feeling pretty miserable, just sick, horrible," said VentureBeat writer Christina Farr.
Last week, Farr called in sick and she began wondering who got her sick. Turns out, there's an app for that -- a Facebook app -- called "Help My Friend Gave Me The Flu!"
"It'll scrape all the data from your difficult social networks. It'll start looking for the telltale signs, search terms like sneeze, cold, flu," said Farr.
In a few seconds, she got a list of four likely suspects who've posted about being sick.
"So, sorry guys, but I'm going to be avoiding you for the next couple of weeks," said Farr.
Crawling Facebook and Twitter for posts about feeling ill, another app called "Germ Tracker" plots likely flu cases on a map.
"People do post on Facebook, and especially Twitter, these short little status updates just saying 'feeling pretty miserable' and mentioning they might be working from home. So these apps can pick up on that," said Farr.
Another map called "Flu Near You" relies on 40,000 volunteers to report every week if they have the flu. Just click on any city.
"And it will show you whether the flu risk is high or not, and whether the people around you are sick," said Farr.
Farr also says her favorite app comes from Google. They have a map that shows who's searching for flu symptoms or remedies.
"People are asking, you know, 'How do I get a fever down?' or 'What kind of medications should I take for the flu?' and Google's updating every single day," said Farr.
Each of the websites paints a slightly different picture, but together, they form a big picture that public health officials say can be just as valuable as the CDC's official numbers.
"Increasingly, we're recognizing in public health is that you need everything. What we really want to do is to be able to triangulate what the numbers exactly are and that takes a combination of traditional methods as well as some of these newer crowdsourcing methods," said Susan Philip, M.D., M.P.H., from the San Francisco Health Department.
But Philip says there's one thing the numbers don't change -- as the flu epidemic sweeps across the country, the best way to fight it is a flu shot.
"For those of us living in California, there's still plenty of time to get a flu vaccine and I would urge everyone to do that," said Philip.
