The Massachusetts Department of Public Health has announced the first positive case of West Nile virus this summer.
Authorities said a mosquito sample collected June 20 in Weymouth tested positive for by the State Public Health Laboratory on Tuesday.
Despite the positive case in the mosquito sample, health officials say there have not been any human or animal cases of West Nile or Eastern Equine Encephalitis so far this year.
"The first WNV positive mosquito sample is often identified in Massachusetts during the last week in June," said DPH Deputy State Epidemiologist Dr. Catherine Brown. "Risk for human infection generally builds through the season with peak risk occurring in August."
Health officials say the virus is usually transmitted to humans through the bite of an infected mosquito.
The virus can infect people of all ages, but people over the age of 50 are at higher risk for severe disease.
Officials say most people who become infected with West Nile will show no symptoms but symptoms tend to include fever and flu-like illness.
Residents are urged to use bug spray to avoid getting bitten. They are also urged to drain standing water near homes.
"The tools for prevention include using a mosquito repellent with an EPA-registered ingredient according to the directions on the label, wearing clothing to reduce exposed skin when weather permits, draining standing water to prevent mosquito breeding and repairing window screens to keep mosquitoes out of your home," Brown said.
In 2017, health officials said there were six human cases of West Nile virus infection in Massachusetts.