Researchers in Florida have pinpointed the local overwintering habitats of Culiseta melanura mosquitoes that host eastern equine encephalitis virus. They hope targeted control efforts can cull those mosquitoes before they transmit the virus to birds that carry it north to other parts of the country. Photo by U.S. Centers for Disease Control and the Connecticut Agricultural Experiment Station, via CDC Public Health Image Library
WORLD

New Hampshire resident dies from Eastern Equine Encephalitis

New insights on mosquito control

TDT

A New Hampshire resident who tested positive for the mosquito-borne eastern equine encephalitis virus (EEEV) has died, marking the first reported case in the state in a decade. The infection, which led to severe central nervous system symptoms, was confirmed by the New Hampshire Department of Health and Human Services on Tuesday. Unfortunately, the victim, identified only as an adult, succumbed to the illness after being hospitalized. EEEV is known for its high mortality rate, with about one-third of those who develop encephalitis from the virus not surviving, and many survivors facing significant long-term disabilities.

The EEEV has also been detected in several mosquito batches and one horse in New Hampshire this summer. The virus has spread to neighboring states as well, with cases reported in Massachusetts and Vermont. The U.S. Centers for Disease Control and Prevention (CDC) notes that there are typically around 11 human cases of EEEV annually in the U.S. Despite its rarity, the virus poses severe health risks, causing symptoms ranging from flu-like signs to severe neurological disease and brain inflammation.

Recent research has shed light on new mosquito control strategies that could help curb EEEV outbreaks. A study led by Dr. Thomas Unnasch at the University of South Florida found that Culiseta melanura, the primary vector of EEEV, has a critical vulnerability. The study revealed that this mosquito species thrives in specific habitats like hardwood swamps and tree plantations. By targeting these areas with preemptive insecticide treatments during the winter, researchers hope to reduce mosquito populations before the peak transmission season. This approach is already being tested in Florida, where mosquito control teams have begun applying these new strategies.

The findings offer a promising avenue for reducing the spread of EEEV, particularly in the northeastern U.S., where the virus has been a persistent threat. Effective mosquito control could play a crucial role in minimizing future outbreaks and protecting public health. 

(Sources: Patrick Whittle, AP; U.S. Centers for Disease Control & Prevention; Leslie Mertz, Ph.D., Entomological Society of America)