Wet summer has not yet increased EEE threat
By LISA RATHKE
The Associated Press | July 28,2013
Despite a wet summer, Vermont’s insect expert isn’t seeing an alarming number of mosquitoes that tend to carry Eastern equine encephalitis, which killed two people in the state last year.
But state entomologist Alan Graham warns that it’s only July and the mosquito season doesn’t reach its height until August.
The state started testing mosquitoes in parts of Addison and Rutland counties June 17. Workers collect mosquitoes and ship them off to a lab in New York to check for EEE and West Nile virus.
Mosquitoes are out in huge numbers after a wet summer that has hatched large numbers of the insects. The state has 45 species of mosquitoes, and just an inch of rain can trigger a breeding frenzy in areas of standing water.
“And they can come off in enormous numbers and indeed they have,” Graham said.
While those species may not carry EEE, they may carry West Nile virus, which also is spread to humans by infected mosquitoes and has turned up in one mosquito pool in Addison County so far this year. West Nile isn’t as severe as EEE, but it can still cause significant illness, said state epidemiologist Erica Berl.
But so far the species that tends to carry EEE is down from last year.
Last September, an 89-year-old man from Brandon and a 49-year-old man from Sudbury died from EEE, a rare and potentially fatal brain infection spread by mosquitoes. Health Commissioner Dr. Harry Chen said then that there are usually only six cases a year nationwide, and it was Vermont’s first time detecting the disease in humans.
The virus can cause two types of human illness.
One comes on suddenly and is characterized by chills, fever, malaise, joint and muscle pain. A more severe illness affects the central nervous system and causes fever, headache, irritability, restlessness, drowsiness, convulsions and coma.
The mosquito species that tend to carry EEE prefer hardwood acidic swamps, which don’t have a lot of water turnover and attract acidic-loving plants, like sphagnum moss, Graham said.
Officials advise residents to take precautions against mosquito bites by avoiding outdoor activities at dusk and dawn, wearing long sleeves and pants, and using insect repellent.
The state could also consider doing aerial pesticide spraying of adult insects as it did last year to cut back on the threat of disease. Some local organizations, such as the Brandon-Leicester-Sudbury-Goshen Insect Control District, routinely spray to kill mosquito larvae in the most active breeding grounds.
There are too many variables to predict if EEE will become a problem, but officials hope testing will serve as an early detection system.
“Our hope is that we’d have a surveillance program that would be able to sort of do an early detection and reduce the number of mosquitoes that might have a risk of transmitting EEE to humans,” Graham said.