MIDDLEBORO — A mosquito collected in Middleboro has tested positive for the West Nile virus, the Board of Health has announced.

The virus is most commonly transmitted to humans by the bite of an infected mosquito. The mosquitos that carry this virus are common throughout the state and are found in urban and rural areas, according to the Board of Health.

The majority of people who are infected with the virus will have no symptoms. About 20 percent of those infected will experience fever, headache, body aches, nausea, vomiting and swollen glands. 

The virus can affect people of any age, although people over 50 are at higher risk of severe infection.

Take steps to avoid mosquito bites, the Board of Health said. These include:

Apply insect repellent when headed outdoors. Use a product with DEET, permethrin, picaridin, IR3535 or oil of lemon eucalyptus. Do not use lemon eucalyptus or children younger than 3 and only apply permethrin to clothing, not directly on skin.

Wear long sleeves, long pants and socks to help keep mosquitoes away from skin.

Be aware of peak mosquito hours. The peak biting time is from dusk to dawn. Consider rescheduling early morning or evening activities. 

To reduce mosquito activity, eliminate standing water; drill holes in the bottom of recycling containers to allow water to drain; change birdbath water every few days and aerate ornamental ponds or stock them with fish.

For more information, visit mass.gov/dph/mosquito.