The Carlisle Mosquito Online

Friday, August 29, 2008

West Nile Virus found in Carlisle

The Massachusetts Department of Public Health (DPH) announced last week that two dead bluejays found in different parts of Carlisle tested positive for West Nile Virus (WNV). As of August 25, there have been no human cases of WNV reported in 2008. In 2007 there were six human cases of WNV.

WNV is a mosquito borne disease which is transmitted to humans by the bite of an infected mosquito. People do not become infected by having direct contact with other infected people, birds or animals. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe infection. The majority of people who become infected with WNV will have no symptoms. A smaller number (20%) may develop mild symptoms such as fever, headache, nausea and sometimes swollen lymph glands. Less than 1% of infected people will develop severe symptoms such as encephalitis or meningitis. There is no specific treatment for WNV infections and people with mild infections usually recover on their own.

Since WNV is most commonly spread by mosquitoes, there are a number of things people can do to protect themselves. The DPH recommends:

Avoid mosquito bites

• Be aware of peak mosquito hours – the hours from dusk to dawn are peak biting times for many mosquitoes.

• Clothing can help reduce mosquito bites. Although it may be difficult to do when it’s hot, wearing long-sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.

• Apply Insect Repellent when you go outdoors. Use a repellent with DEET, permethrin, picaridin and oil of lemon eucalyptus according to the instructions on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30% or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age. Permethrin products are intended for use on items such as clothing, shoes, bed nets and camping gear and should not be applied to skin.

Mosquito-proof your home

• Drain standing water – Mosquitoes can begin to multiply in any puddle or standing water that lasts for more than four days.

• Install or repair screens.

Report dead birds

Once two positive birds have been detected in a community, there is no need to test additional birds in that community or in neighboring towns. The state is still interested in dead bird reporting, particularly Blue Jays and Crows, for its ongoing surveillance of WNV activity. Residents should call 1-866-MASS WNV to report dead birds.

WNV in horses

Horses can become infected with WNV. There is no evidence of horse-to-human or horse-to-horse transmission of WNV. A vaccine is available for horses. For more information on WNV in horses check the websites below.

Information about WNV is available on the Board of Health website at and on the MDPH website at under A for Arbovirus in the “Health Topics A to Z” index.

The Board of Health will be discussing how to deal with mosquito-borne illnesses on Thursday, October 2, at 8 p.m. at Town Hall. The board has invited David Henley of the East Middlesex Mosquito Control Program to talk about current mosquito control practices. ∆

West Nile Virus Cases


© 2008 The Carlisle Mosquito