West Nile virus detected in mosquitoes in Edgartown

Edgartown Board of Health confirmed Thursday that samples taken from mosquitoes tested positive for West Nile virus. — Jedesto/WikimediaCommons

On Thursday, the Massachusetts Department of Public Health (DPH) and the Edgartown board of health announced West Nile virus was recently detected in mosquitoes in the cemetery area in Edgartown. 

West Nile virus is the leading cause of mosquito-borne disease in the U.S., according to the Centers of Disease Control (CDC).

Edgartown health agent Matt Poole told The Times that test samples from a particular species of mosquito, Culex pipiens, which are common on the Vineyard, have tested positive for West Nile. 

Bites from infected mosquitoes can transmit the virus to humans, birds, and other mammals, and are most prevalent during the summer and fall months. 

According to DPH, only around 1 in 5 people who become infected with West Nile virus develop symptoms, so the actual number of humans infected cannot be exactly quantified. Symptoms can include fever, headache, body aches, nausea, vomiting, swollen lymph glands, and skin rashes.

About 1 out of 150 people who become infected with the virus develop a severe, sometimes fatal, illness. Serious symptoms consist of high fever, neck stiffness, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis, which can be signs of severe illness such as encephalitis or meningitis. People over 50 and those who have immune deficiencies from pre-existing conditions have an increased risk of developing serious illnesses. 

As there are currently no vaccines or medications to treat West Nile virus, the Edgartown board of health suggests keeping in mind the peak mosquito hours — dusk to dawn — when participating in outdoor activities, and to keep skin covered when possible to reduce the risk of bites. 

Mosquitoes typically lay their eggs in stagnant water, so emptying out items that hold standing water, such as gutters, drains, birdbaths, etc., can help limit mosquito breeding in the vicinity. 

The DPH and board of health suggest applying insect repellents to clothing and shoes, but avoid contact with skin. Some common repellents that are effective against mosquitoes are DEET, permethrin, picaridin, IR3535, or oil of lemon eucalyptus.