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Three horses test positive for West Nile virus; Marion remains under mosquito-borne illness advisory

November 15, 2018


OCALA, Fla.—Even though weather is turning cooler outside, residents should continue to take precautions against mosquitoes when outdoors. Three Marion County horses tested positive for West Nile virus recently, meaning the mosquito-borne virus is active in the community.

West Nile virus is a disease that can spread to people and animals through the bite of an infected mosquito. People typically develop symptoms two to 14 days after they are bitten. There is no specific treatment for West Nile virus, and most mild infections are typically overcome with little or no medical intervention within a few weeks. Eighty percent of people infected show no symptoms, and up to 20 percent can show mild symptoms, such as body aches, vomiting and nausea. About one in 150 people infected develop serious illness, with symptoms such as neck stiffness, paralysis, vision loss and tremors; neurological effects may be permanent, and severe illness can lead to death.

Marion County has been under a mosquito-borne illness advisory since May and remains under one due to ongoing mosquito activity. The advisory was originally issued due to an uptick in Eastern equine encephalitis (EEE) virus. EEE cases have decreased in recent months, and West Nile virus cases have increased statewide.

The state issues advisories to inform residents that they face an increased risk of diseases spreading to humans from mosquitoes through mosquito bites. According to the Centers for Disease Control and Prevention, people most at risk for infection with mosquito-borne virus include those who work outside or spend time doing outdoor recreational activities because of added exposure to potentially infected mosquitoes.

“Take preventative actions when you are outdoors to avoid exposure to mosquitoes,” said Florida Department of Health in Marion County Health Officer Mark Lander. “Drain standing water around your home or property, cover your skin with clothing or repellent and speak with your veterinarian about what vaccinations may be available for your animals.”

The department continues to conduct statewide surveillance for mosquito-borne illnesses, including West Nile virus, Eastern equine encephalitis, St. Louis encephalitis, malaria, chikungunya, and dengue. For more information, visit