Florida’s first locally transmitted case of Zika in 2017 was confirmed in Manatee County on Thursday, the state health department reported.
Health officials said they have no additional evidence that mosquitoes are spreading the virus in Manatee County, which is on the Gulf Coast, south of St. Petersburg and Tampa. But the health department said it alerted the county’s mosquito control and that local officials had begun spraying and other reduction efforts.
Health officials said the case emerged after a couple had traveled to Cuba and one partner became ill with symptoms consistent with Zika shortly after returning to Florida. Zika causes symptoms in one out of five infected people, including muscle aches, fever, a rash and red eyes.
An epidemiological investigation by the health department suggests that the traveler contracted Zika in Cuba, was bitten by a mosquito in Florida, and the insect then spread the virus to the infected person’s partner.
The traveler who is believed to have acquired Zika in Cuba was not tested for the virus while symptomatic, the health department said. But a test performed this week showed evidence of a past Zika infection, linking the traveler’s case to the other person, who tested positive.
The total number of Zika cases in Florida this year is 187, including 107 pregnant women. One case was transmitted through sex, and in 32 cases, epidemiologists could not determine the source of infection. Most cases this year were contracted by people who traveled to one of the 75 countries where the World Health Organization says mosquitoes are spreading the virus.
The virus poses the greatest threat to pregnant women because the virus can cause birth defects and neurological problems in the fetus.
Zika sparked a public health crisis in Florida in 2016, with nearly 1,500 infections statewide, including 300 local cases, most spread by mosquitoes in Miami-Dade County. But the virus has waned this year.
Prior to Thursday, the last confirmed case of Zika spread by mosquitoes in Florida was confirmed in December. Only one state, Texas, has reported a mosquito-borne infection this year.
Zika is primarily spread through the bite of an infected Aedes aegypti mosquito. There is no vaccine or treatment for the virus, which can also spread through sexual contact.