MIAMI (CBSNewYork/AP) — The CDC is working with Florida health officials to investigate what could be the first Zika infection from a mosquito in the continental United States.

They say lab tests confirm a person in the Miami area is infected with the Zika virus, and there may not be any connection to someone traveling outside the country.

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Mosquito control inspectors were at work in Miami-Dade County on Wednesday. Spokeswoman Gayle Love said they’ve been going door-to-door since health authorities alerted them late last week, spraying to kill mosquitoes and emptying any containers holding water.

The U.S. Centers for Disease Control and Prevention says none of the more than 1,300 Zika infections in the United States to date were from local mosquitoes. Fourteen were sexually transmitted and one involved laboratory exposure.

Last week, it was reported that a New York City woman infected her male partner with the Zika virus through sex, the first time female-to-male transmission of the disease has been documented.

The CDC now advises pregnant women to use protection if their sex partner has traveled to a Zika-infected region, whether the partner is a man or a woman.

The Zika virus causes only a mild illness, at worst, in most people. But it can cause fetal deaths, microcephaly and other severe birth defects in the children of women infected during pregnancy. The New York woman was not pregnant.

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