Mosquitoes have apparently begun spreading the Zika virus on the US mainland for the first time, health officials said Friday in 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, Governor Rick Scott said at a news conference.
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 US Centres for Disease Control and Prevention.
Still, US health officials said they do not expect widespread outbreaks in this country of the sort 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 warmer latitudes of the Western Hemisphere. While most people who get Zika don’t even know they are sick, infection during pregnancy can cause babies to born with disastrously small heads and other severe brain-related defects.
More than 1,650 people in the mainland US have been infected with Zika in recent months. The four people in Florida are believed to be first ones to contract the virus within the 50 states from mosquitoes.
“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 reassure tourists that it’s still safe to visit the state.
Some medical experts said pregnant women should not travel to the Miami area, especially if it involves spending time outdoors. However, the CDC is not issuing such advice.
US health officials said the US might see small clusters of infections. But “we don’t expect widespread transmission in the continental United States”, the CDC’s Frieden said.