Mosquitoes Test Positive For West Nile Virus In Greenwich

GREENWICH, CT — Greenwich is attempting to control the local mosquito population after some that were trapped near the Eastern Civic Center in the Old Greenwich area of town tested positive for West Nile virus, according to an announcement from the state's Mosquito Management Program. These are the first mosquitoes to test positive for the virus in town this year, according to the Greenwich Health Department.

In response, the town will continue a process known as "larviciding," in which insecticides are sprayed in catchbasins, targeting insects in their larval stage. This will include the treatment of catchbasins on public and private roadways, public school grounds and other property owned and operated by the town, according to a statement from the health department.

This year's larvicide program began in June and is reapplied every four to six weeks.

"Controlling the mosquito population in the larval stage through the application of larvicide has been found to be a prudent action," Health Director Caroline Calderone Baisley said in a statement, "however, this measure only helps to reduce the mosquito population, not eliminate it. The recent warm weather and periodic rain events have increased the ability for mosquitoes to breed. Residents are encouraged to protect themselves whenever they are outdoors."

Director of Environmental Services Michael Long also emphasized that residents should to take steps to protect themselves from mosquito bites, such as wearing long-sleeved shirts and long pants and avoiding outdoor activities at dawn and dusk, when the insects are most active.

"Although the town's larvicide program treats catchbasins, the general public must be vigilant in eliminating standing water on their own properties and protecting themselves from biting mosquitoes at all times," Long said in a statement. "It is important to recognize that the highest risk of exposure to West Nile Virus infected mosquitoes is during the months of August and September."

According to the department, the virus is spread to humans after being bitten by an infected mosquito, which itself becomes infected after biting a bird carrying the virus. It is not spread by person-to-person contact or directly from birds to people.

Most people who are bitten by an infected mosquito are able to fight off infection and experience mild or no symptoms at all, however some people with compromised immune systems can develop serious illness from the virus that affects their central nervous system.

"The finding of WNV positive mosquitoes in Greenwich marks the time to emphasize that personal protection measures are extremely important against biting mosquitoes during the day and at night," Baisley said.

The health department recommends taking the following precautions when outside:

• Avoid outdoor activities at dawn and dusk when mosquitoes are most active.
• Wear long sleeved shirts and long pants.
• Use mosquito repellent according to the manufacturer’s directions on the label (10 percent or less DEET for children and no more than 30 percent DEET for adults), and always wash treated skin when returning indoors.
• Avoid application of repellents with DEET on infants and small children.
• Cover arms and legs of children playing outdoors.
• Cover playpens or carriages with mosquito netting.
• Don't camp overnight near stagnant or standing water.

Residents can also eliminating standing water by taking the following precautions:

• Get rid of any water holding containers (old tires, etc.).
• Rake out puddles and drain ditches, culverts, gutters, pool and boat covers.
• Cover trash containers.
• Chlorinate your backyard pool and empty wading pools when not in use.
• Change the water in birdbaths daily.
• Keep grass cut short and shrubbery well trimmed around the house so adult mosquitoes cannot hide there.
• Ponds and stagnant water bodies that do not support fish, frogs or other amphibians that eat mosquito larvae may be treated with a biological control agent such as Bacillus thuringiensis israelensis (BTI). It is suggested that the Department of Health or Conservation be contacted when treatment is considered.

The State Mosquito Management Program will continue to trap and test mosquitoes at three testing sites in Greenwich as part of their program, and will continue to do so through October.

Last year, 23 Connecticut residents developed WNV-associated illness, according to the health department. Those cases were not fatal.

On Friday, Stamford officials announced local mosquitoes had tested positive for West Nile virus. Larviciding was scheduled to continue in the city on Monday.