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‘Sentinel chickens’ implicate Florida Panhandle as epicenter for Eastern equine encephalitis virus in US

Suman R. Das

An analysis of “sentinel chickens” implicated the Florida Panhandle as the likely epicenter for Eastern equine encephalitis virus, or EEEV, in the United States, according to findings reported in The American Journal of Tropical Medicine and Hygiene.

Suman R. Das, PhD , associate professor of medicine at Vanderbilt University, told Infectious Disease News that EEEV has been “lurking” in the U.S. for more than a decade, and that sporadic outbreaks of the mosquito-borne disease have been reported. Although only 70 cases of EEEV have been reported in humans since 2008, the disease is associated with a high mortality rate and requires intensive surveillance, according to a press release

“EEEV is the deadliest virus we can potentially be exposed to in the United States, with a mortality rate at about 30% to 40%, and severe neurological sequelae in the survivors,” Das said. “This could be the next ‘Disease X’ that the WHO has been warning us about, and we should definitely be closely keeping track of this virus.”

Das and colleagues analyzed blood samples from thousands of chickens used by state health officials in Florida from 2005 to 2016 to investigate transmission patterns and characterize the epidemiological and evolutionary dynamics for EEEV.

Researchers monitored thousands of chickens in Florida for Eastern equine encephalitis virus . Source: Adobe Stock

“Sentinel chickens are serving, as some say, as a ‘canary in the coal mine‘ in helping us track the activity of these pathogens in Florida,” Das explained.

According to a news release, although chickens can be infected with EEEV, they do not get sick or transmit the disease.

The study revealed extensive genetic diversity as well as spatial dispersal of EEEV within Florida. Additionally, Das and colleagues observed more clustering of the disease in the Panhandle region. The findings, they said, indicate that EEEV is present year-round in the Florida Panhandle and that the region could be “seeding” EEEV epizootics in the rest of the state and the Northeastern U.S.

“We have previously shown Florida to be the source of the Northeastern outbreaks. Now based on the sentinel and virus genome sequencing data, we show the Florida Panhandle and to some extent South or South Central Florida, have year-round activity and overwintering,” Das concluded. “Eradication of EEEV in these regions will potentially significantly curtail EEEV activities.” – by Marley Ghizzone

Disclosures: Suman reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.