A mosquito sample in Richardson has tested positive for the West Nile virus in the first confirmed tests of the year, Dallas County Health and Human Services reported.

The mosquito traps were collected from the 75080 ZIP code, the department said in a news release.

Dallas County sets mosquito traps year-round in 47 locations, including in parks and residents' yards. Ten municipalities set an additional 175 traps from May to November.

A health department lab tests the specimens, and the county responds with ground spraying if workers detect West Nile.

West Nile is spread by the bite of mosquitoes that become infected when they feed on blood from infected birds. The disease can then be transmitted to humans and animals. Severe cases can cause encephalitis, while milder symptoms include fever, headache and muscle aches.

Last year in Dallas County, 199 mosquito traps tested positive, 13 people became infected with the disease and one died.

The best way to avoid exposure to the virus is to avoid mosquitoes. Anyone outside should use insect repellents that contain DEET or other EPA-registered repellents.

Other suggestions include wearing long, loose and light-colored clothing outside; and draining and treating standing water around homes and places where mosquitoes could lay eggs.

Staff writer Anna Kuchment contributed to this report.