For the first time in the continental United States, researchers have confirmed positive tests for Zika virus in mosquitoes trapped near Miami. Just weeks after the Centers for Disease Control issued a historic warning for a 1.5-square-mile neighborhood in northern Miami, the Florida Department of Agriculture and Consumer Services announced Thursday that the three mosquito samples that tested positive for Zika were from that affected area. Health officials had already determined that at least five of Florida’s human cases of Zika had been contracted locally, so finding the Zika-positive mosquitoes comes as no surprise.
Since the CDC health alert went into effect, Miami-Dade County officials have been working to control local mosquito populations in an effort to reduce the risks of Zika. The virus is spread by the Aedes aegypti mosquito as well as through sexual contact and most infected patients feel only minor flu-like symptoms. However, contracting Zika virus during pregnancy can lead to microcephaly, a severe birth defect that results in children needing lifelong care. Women who may become pregnant in the near future, and their partners, are also urged to take extra precautions when living or traveling in Zika hotspots.
Of the three Zika-positive mosquitoes, officials said that one came from traps at the botanical garden. The locations of the other two positive samples were not revealed. It is also not known to the public when any of the Zika-positive mosquitoes were trapped. Miami-Dade County Mayor Carlos Gimenez said 16 other mosquito traps in the county tested negative and tests on other samples are ongoing.
Confirming Zika-positive mosquitoes and knowing the locations where they were trapped will help local officials focus mosquito control efforts. Mosquitoes travel just a small radius—not more than 150 meters—during their short lifespans, so the positive tests allow officials to create a detailed map of Zika risks. Although eradicating the mosquitoes that carry the virus is highly unlikely, officials are hopeful that the testing and control measures, along with the public health alerts, will keep Zika cases to a minimum.