State starts testing mosquitoes for disease
Ah, the signs of summer -- lawn sprinklers, children playing in parks and the annoying buzz of mosquitoes in the air.
Not only are these insects nuisances, they can also carry diseases, including West Nile virus and eastern equine encephalitis virus.
Last Tuesday, Connecticut's Mosquito Management Program began trapping mosquitoes at 91 locations throughout the state and testing them for West Nile and EEE. Testing will be done throughout the summer. Results of the first round of testing may be available next week.
Last year, West Nile-positive mosquitoes were trapped in 16 towns, and EEE was found in mosquitoes trapped in 24 towns. However, no Connecticut residents were identified with West Nile or EEE
Experts said it's difficult to predict what kind of season we'll have this year, but Randall Nelson, a senior epidemiologist with the state Department of Public Health, said it's almost certain that at least some insects in the state will test positive for the diseases. "West Nile virus is here every year," Nelson said. "The question becomes, is it at a low level or is it rising?"
Locally, West Nile seems to be more of a concern. Since 2000, 69 human cases of the illness and two fatalities have been reported. Last year was the first year since 2000 without human cases of West Nile in Connecticut, said Theodore Andreadis, chief medical entomologist and director of the mosquito trapping and testing program for the Connecticut Agricultural Experiment Station in New Haven. Andreadis said West Nile seems to be tapering off nationally as well.
However, like Nelson, Andreadis said West Nile is still in the state. "It is permanently established and we will see it again," Andreadis said.
Though both are linked to mosquitoes, EEE and West Nile are distinctly different diseases. EEE is a virus that is present in nature and linked to the wild bird population through a certain species of bird-feeding mosquitoes. The virus has no effect on wild birds but can be fatal to humans, horses and commercial exotic fowl, such as pheasants. In Connecticut, outbreaks of EEE have occurred occasionally among horses and domestic pheasants since 1938, but no human cases have been confirmed, although human deaths from the illness have been reported in nearby states.
West Nile virus is relatively new to the Americas, and was discovered in Connecticut, New York and New Jersey in 1999. According to the state Department of Health, West Nile causes fatal illness in a smaller proportion of cases than EEE, but has a greater potential to cause large outbreaks.
West Nile tends to be more common in lower Fairfield and New Haven counties, whereas EEE is more abundant in the eastern part of the state. Andreadis said he didn't expect to find any mosquitoes with the diseases until July or August.
Meanwhile, Nelson said residents should protect themselves from mosquito bites. One way they can do that is by utilizing screens on doors and windows, which will help keep the creatures out.
Another way to limit mosquito exposure is get rid of standing water. Nelson said birdbaths, pool covers and other containers that can collect and hold water are popular breeding grounds.
"You can cut down on mosquitoes quite a bit if you remove standing water," he said.
For information on mosquitoes, visit the Connecticut Mosquito Management Program website at www.ct.gov/mosquito.