U.S federal officials have announced a contest for developers to design Web-based applications that use Twitter to track health trends in real time.

The U.S. Department of Health and Human Services issued the challenge Tuesday for developers to participate in the contest called Now Trending -- #Health in My Community.

Health officials say they may be able to use knowledge of these trends as an early indicator of emerging health issues and a warning of public health emergencies in a community.

"When we looked back at the H1N1 pandemic, we saw that, in some cases, social media trends provided the first clues to flu outbreaks," Nicole Lurie, assistant secretary for preparedness and response, said in a Health and Human Services release.

"Based on that 2009 pandemic experience, local health officials asked for our help in developing a Web-based tool that could make social media monitoring useful as part of the surveillance systems in place now to identify new diseases early."

To win the challenge, officials said, the application must be innovative, scalable, dynamic and user-friendly, and must use open-source Twitter data to automatically deliver a list of the top five trending illnesses over a 24-hour period in a specified geographic region.

The online challenge runs through June 1.