MIAMI — Mosquitoes have apparently begun spreading the Zika virus on the U.S. mainland for the first time, health officials said Friday, a long-feared turn in the epidemic that is sweeping Latin America and the Caribbean.
MIAMI — Mosquitoes have apparently begun spreading the Zika virus on the U.S. mainland for the first time, health officials said Friday, a long-feared turn in the epidemic that is sweeping Latin America and the Caribbean.
Four recently infected people in the Miami area — one woman and three men — are believed to have contracted the virus locally through mosquito bites, Gov. Rick Scott said.
No mosquitoes in Florida have actually been found to be carrying Zika, despite the testing of 19,000 by the state lab. But other methods of Zika transmission, such as travel to a stricken country or sex with an infected person, have been ruled out.
“Zika is now here,” said Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention.
Still, U.S. health officials said they do not expect widespread outbreaks in this country like those seen in Brazil, in part because of better sanitation, better mosquito control and wider use of window screens and air conditioners.
The virus has triggered alarm across the Western Hemisphere’s warmer latitudes. While most people who get Zika don’t even know they are sick, infection during pregnancy can cause severe brain-related birth defects, including disastrously small heads.
More than 1,650 people in the mainland U.S. have been infected with Zika in recent months, nearly all while traveling abroad. The four people in Florida are believed to be first to contract the virus from mosquitoes within the 50 states.
“This is not just a Florida issue. It’s a national issue — we just happen to be at the forefront,” Scott said.
Florida agricultural officials immediately announced more aggressive mosquito-control efforts, and Florida politicians rushed to assure tourists it’s still safe to visit the state.
Some medical experts said pregnant women should not travel to the Miami area, especially if the visit involves spending time outdoors. The CDC is not issuing such advice, however.
Health officials said the U.S. might see small clusters of infections. But “we don’t expect widespread transmission in the continental United States,” the CDC’s Frieden said.
The four Florida infections are thought to have occurred in a small area just north of downtown Miami, in the Wynwood arts district, the governor said.
The area, known for bold murals spray-painted across warehouses, art galleries, restaurants and boutiques, is rapidly gentrifying and has a number of construction sites where standing water can collect and serve as a breeding ground for mosquitoes.
People in Florida’s Miami-Dade and Broward counties are being tested to learn whether there are more cases, the governor said.
“If I were a pregnant woman right now, I would go on the assumption that there’s mosquito transmission all over the Miami area,” warned Dr. Peter Hotez, a tropical medicine expert at the Baylor College of Medicine in Texas.
He said that there are probably more cases that have not been diagnosed, and that people should not be surprised if mosquitoes are soon found to be spreading Zika in Louisiana and Texas as well.
Earlier this week, federal authorities told blood centers in the Miami-Fort Lauderdale areas to stop collecting blood until they screen it for the virus.
Zika’s symptoms can include low-grade fever, rash, joint pain, headaches and inflamed eyes and typically last seven to 10 days. None of the four people infected in Florida are showing symptoms anymore, officials said.
Frieden said the evidence suggests that the mosquito-borne transmission occurred several weeks ago over several city blocks.