A dead catbird found in Manatee County has tested positive for the West Nile virus.
Tests completed Friday show the dead bird, found Oct. 17 in the Whitfield Estates area of southwestern Manatee County, was infected with the virus, said John Burns, an environmental health engineer.
No human case of the potentially fatal mosquito-borne virus has been reported in Manatee County, Burns said.
Manatee and surrounding counties are not under state medical alert for a potential threat to humans.
With cooler, drier weather holding down the mosquito population, the risk level is low, said Mark Latham, director of the Manatee County Mosquito Control District.
Latham said more mosquito traps will be put out.
"We don't expect to pick up much," Latham said. "That was a migratory bird. Whether that bird even contracted West Nile in this county is up for debate, but obviously we have to make that assumption."
Latham's staff draws blood every two weeks from more than 40 chickens across the county to test for West Nile and two sister viruses, St. Louis encephalitis and Eastern Equine encephalitis. This year none has tested positive for any of the three viruses, he said.
West Nile virus has been found in other areas of the Tampa Bay area, including Hillsborough and Pinellas counties. However, no dead wild birds were found in either county, suggesting the virus is in very low levels, epidemiologists said.
Symptoms of West Nile virus in humans include fever, severe headache, stiff neck, fatigue, dizziness, weakness or confusion. The virus can be fatal by causing swelling of brain tissue.
Fifty-three of the 67 counties in Florida are under state medical alert since West Nile first surfaced in north Florida wildlife earlier this year. Eleven Floridians have been infected and all survived.
Five people nationally have died this year after contracting the virus.