Disease experts team up with Florida Museum of Natural History to create a forecast for West Nile virus

Key points

State and local officials in Florida maintain hundreds of coops with what are referred to as sentinel chickens, which act as an early alarm system for the presence of mosquito-borne illnesses in an area. This alarm system just got an upgrade.
An interdisciplinary team of experts, including a zoonotic disease specialist, a museum data scientist and a salamander biologist, have combined their skills and created a statistical model that accurately predicts the activity of West Nile virus in an area up to six months in advance.
The model was trained using two decades of sentinel chicken data. The original data files were destroyed in a flood, and the study was only possible because a University of Florida professor kept a personal copy in his lab.

A new study has significant bearing on the hackneyed joke about chickens and their numerous reasons for crossing roads. In Florida, there’s a good chance that the chicken crossed the road because it had completed its year-long conscripted service as a disease sentinel, a sort of early alarm signal for mosquito virus activity across the state.

Mosquito control programs maintain hundreds of chicken coops from the Panhandle down through Miami. Once a week, throughout large portions of the year, officials take a small blood sample from each of several chickens and send them to the Florida Department of Health, where they’re tested for antibodies to common mosquito-borne diseases, such as West Nile virus and eastern equine encephalitis. If the results are positive, the state will warn residents to be especially wary of mosquitos until the danger is past.

There’s no way to know with certainty, but the state’s sentinel program, which has been ongoing for more than 40 years, has likely saved many lives. But the program has its limitations, the most obvious being that warning can only be given after the confirmed virus activity, by which time people may have already been exposed.

Researchers at the University of Florida want to change that. In the study, published in the journal Science of the Total Environment, they demonstrate that they can reliably predict elevated West Nile virus activity in chickens up to six months before it occurs, which they accomplished by training and testing a statistical model on 20 years’ worth of sentinel chicken data. Their results are an important first step toward forecasting West Nile virus across Florida.

“People have spent years testing these chickens, and one of the main reasons is to get to the point where you can make predictions,” said study co-author Rob Guralnick, curator of biodiversity informatics at the Florida Museum of Natural History. He described the results as an exclamation point to the work that’s been done up to this point.

With this and future models added to their toolkit, health officials may one day soon be able to supplement their reactionary mitigation responses to disease outbreaks with proactive preventative measures.