Health officials in Florida were investigating Wednesday what could be the first Zika infection from a mosquito bite in the continental U.S.
Lab tests confirmed that the person in the Miami area has the Zika virus, according to statements from the U.S. Centers for Disease Control and Prevention and Florida's Department of Health.
Health officials said the person has no apparent links to recent travel outside the country, but no additional information was released. They did not immediately respond Wednesday to questions about why they believe the infection is not travel-related, and whether the possibility of sexual transmission has been ruled out.
More than 1,300 Zika infections have been reported in the U.S., but none involved bites from local mosquitoes, according to the CDC. Fourteen cases were sexually transmitted and one lab worker was stuck with a contaminated needle.
Miami-Dade County has the most confirmed infections in Florida so far — 88, but all have been found to be travel-related.
Mosquito control inspectors have been going door-to-door in the area under investigation since health authorities alerted them late last week, spraying to kill mosquitoes and emptying containers of the water they need to breed. If the virus is there, they want to keep it from spreading through more mosquito bites.
"We're constantly in the area. We're doing hand-held spraying, and we'll do more truck spraying Thursday," said Gayle Love, a spokeswoman for Miami-Dade County Solid Waste Management.
Zika prevention kits and mosquito repellent — strongly recommended for women who are pregnant or planning to be pregnant — are being distributed in the area and can be picked up at the health department as well.
In most people, Zika causes only a mild and brief illness, at worst. But it can cause fetal death and severe brain defects in the children of women infected during pregnancy.
There is no vaccine. In outbreak areas, the main defense is to avoid mosquito bites. Zika also can be spread through unprotected sex with someone who is infected.
Health officials worldwide have advised pregnant women not to travel to areas where Zika is spreading.
The CDC also recommends that women wait at least eight weeks after a Zika illness, or possible exposure to the virus, before trying to conceive. Men who had symptoms should wait at least six months before trying.