There have been 12 additional mosquito samples that tested positive for West Nile virus in Suffolk County this season, according to the Suffolk County Department of Health Services.

The latest positive samples bring the season's total to 139.

The most recent mosquitoes carrying the virus were collected Sept. 8 in Bridgehampton and Shelter Island. Additional positive samples collected the following two days from Lindenhurst, Copiague, Setauket, Rocky Point, Fire Island Pines, Watch Hill on Fire Island and Bay Shore.

Health officials also reported that three mosquito samples this season tested positive for Jamestown Canyon virus, another mosquito-borne disease.

Earlier this summer, two dead crows found in Ronkonkoma and a dead blue jay in Nesconset also tested positive for West Nile virus.

West Nile virus spreads to humans through the bite of an infected mosquito.

The department says while most people experience mild symptoms or none at all, some can develop serious illness, including high fever, headache, neck stiffness, confusion, vision loss, muscle weakness, paralysis and possibly death.

The health department is urging residents to take precautions against mosquito bites, especially people 50 and older and those with weakened immune systems, who face a higher risk of severe illness.