A fourth mosquito sample has tested positive for West Nile virus in Will County this year.

The sample was taken from a trap located in southwest suburban Lockport, the Will County Health Department said. The other three positive samples had been found in traps in Manhattan, Plainfield and Joliet.

Cook and DuPage Counties have also found mosquitos that tested positive for West Nile this year, WCHD said in a previous statement. According to the Center for Disease Control, no human cases have been reported in Illinois so far.

In 2018, four human cases were reported in Will County and 176 were reported around the state — 17 of which were fatal, according to WCHD and the Illinois Department of Public Health.

West Nile virus is passed from infected birds to humans through the bite of the Culex mosquito, WCHD said. Health authorities recommend wearing long-sleeved clothing and insect repellent with DEET during the peak mosquito hours of dusk to dawn.

Additionally, WCHD is advising people to remove standing water from their property since mosquitos are known to lay eggs in places such as gutters, birdbaths and kiddie pools.

West Nile can include fever, headache, body aches and swollen lymph nodes, WCHD said. Seniors, young children and people with weakened immune systems are particularly at risk.