Aedes albopictus is one of two mosquito species that transmit chikungunya virus, recently reported in the United States.

CDC/James Gathany

Aedes albopictus is one of two mosquito species that transmit chikungunya virus, recently reported in the United States.

Chikungunya threat inspires new DARPA challenge

Kelly is a staff writer at Science.

The research branch of the U.S. Department of Defense wants to know when and where the next outbreak of the mosquito-borne chikungunya virus will occur, and it’s offering $150,000 for the best new approach. The Defense Advanced Research Projects Agency (DARPA) today announced its first health-related challenge, which asks scientific teams to forecast over 6 months how the debilitating disease might spread in the Americas and the Caribbean.

Why is the Defense Department taking a special interest in chikungunya? For starters, “it’s a really bad infection,” says Matthew Hepburn, a program manager in DARPA’s Biological Technologies Office, who will run the challenge. The virus causes high fever, joint and muscle pain, headache, nausea, fatigue, and rash. It’s very rarely fatal, but the painful swelling of joints can be disabling and sometimes persists for months. With U.S. military deployed worldwide, “we have a strong interest in … trying to prevent our soldiers from being infected,” he says.

But recently, the threat has gotten much closer to home. Once considered a disease of developing countries in African and Asia, chikungunya got a burst of scientific attention when it popped up on the French island of La Reunion in 2007. Then last December, it reached the island of St. Martin, and has now caused hundreds of thousands of cases in the Caribbean. The first four locally acquired cases in the United States were reported in Florida last month. Currently, there is no vaccine available.

Hepburn says DARPA wants to find technologies that U.S. health officials can use to make decisions in the case of an outbreak. “It’s one thing to know what’s happening on the ground currently,” he says, “but really to design your response decisions, you need to know what’s going to happen next.” Forecasts of how severe an outbreak will be, where it might move, and who is most susceptible would help health officials concentrate resources in the right places, killing mosquitos and their larvae, or eliminating out potential breeding grounds in places of high risk.

The challenge drew inspiration from a similar competition at the U.S. Centers for Disease Control and Prevention (CDC) focused on influenza prediction—a field that has received more scientific attention than chikungunya and benefits from an annual influx of data during the peak season. CDC’s winning submission, announced in June, combined Google and CDC data to accurately predict the peak and intensity of the 2013 to 2014 season.

Chikungunya forecasting is not as far along as influenza, says Justin Lessler, an epidemiologist at Johns Hopkins University in Baltimore, Maryland, who specializes in infectious disease dynamics. But in terms of a scientific problem to tackle, he calls the disease “a pretty good choice” for a DARPA challenge. It’s an emerging threat in the Americas, but cases have been recorded in Africa and Asia for decades, meaning that there is plenty of historical data to work with, but it’s not clear how it will apply to a possible outbreak here. He’s optimistic that better forecasting for chikungunya could also be useful in informing predictions about other mosquito-borne diseases, such as dengue fever.

To participate in the challenge, researchers must make a submission every month, guessing how many chikungunya cases will occur over the remainder of the 6-month competition in each of the 35 member countries of the Pan American Health Organization. The design of the contest demands speedy predictions early on—contestants have to send their first estimates on 1 September—but then rewards teams for improving their accuracy as the challenge progresses. In the end, DARPA will award $150,000 and $100,000 to the two top-scoring teams and four honorable mention awards of $50,000 each.

That kind of prize money might not lure in teams who don’t already have some resources to throw at the chikungunya problem, Lessler predicts, though it may inspire some new collaborations between groups.

“I’m not convinced that that we’ll see any earth-shattering advances,” he says, “but I’d be happy to be surprised.”

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