Pregnant women should avoid all non-essential trips to Florida because of the risk of contracting the Zika virus, British officials have said, after the first cases of Zika transmitted by mosquitoes on the US mainland were confirmed in the state. The advice comes as thousands prepare to visit the popular tourist destination.
Florida and national health officials reported the first local transmission of the Zika virus in a US state on Friday, as the state began an “aggressive” investigation and federal authorities short of funding braced themselves for a health crisis.
Governor Rick Scott reported that four people in southern Florida were likely to have contracted the virus through local mosquito bites, even though no insect trapped and tested in the state has yet proved positive for the virus.
“These are the first cases of locally transmitted Zika virus in the continental United States,” said Tom Frieden, the director for the Centers for Disease Control. “Zika is now here.”app
Although health officials have confirmed more than 1,600 cases of the virus across America, every patient bar the four reported in Florida contracted the disease either travelling abroad or through sexual transmission. In Puerto Rico, there are more than 4,500 cases of the virus, virtually all contracted through mosquitoes.
As many as 50 pregnant women a day are affected in the US territory, according to the Centers for Disease Control. “This is a silent epidemic that is rapidly spreading through Puerto Rico,” Frieden said.
The Florida report followed an announcement on Thursday that blood donations had been suspended in the affected area until all current samples could be tested. Two of the cases suspected of local transmission were in Miami-Dade county and two in Broward county, Scott said. The patients included one woman and three men, and none has needed hospital care.
Health officials believe that the infections occurred in an area of about a square mile just north of downtown Miami. Officials are now going door to door in the area offering to test people, and Scott said that they would be “aggressively testing”.
“While no mosquitoes trapped tested positive for the Zika virus, the department believes these cases were likely transmitted through infected mosquitoes in this area,” the Florida health department said. “All the evidence we have seen indicates that this is mosquito-borne transmission that occurred several weeks ago in several blocks in Miami,” Frieden added.
Earlier in July, authorities began investigating the possible first local transmission of Zika, but Scott’s near-confirmation on Friday amounted to a serious development of the feared health crisis. There have been 386 cases of Zika reported in Florida so far, mostly in Miami-Dade and Broward counties. Fifty-five pregnant women have been affected.
“Florida is taking an aggressive approach,” Scott confirmed. “We have worked hard to stay ahead of the spread of Zika and prepare for the worst.”
Scott emphasised that there had been no reported cases of local transmission of Zika in central parts of the state. The Orlando area is teeming with summer visitors from all over the US and the globe, attending the cluster of theme parks such as Disney World, Universal Studios and SeaWorld.
Officials fear local transmission because local mosquitoes could spread the disease far more rapidly than isolated travel or sex.
More than a million British nationals visit Florida each year. The updated travel advice from Public Health England, which comes as many are expected to visit the state’s theme parks this summer, reads: “The risk in Florida is considered moderate based on the number and spread of cases and their demonstrated ability to implement effective control measures for similar diseases such as dengue – a virus transmitted by the same mosquito.
“Pregnant women should consider postponing non-essential travel to affected areas until after the pregnancy. At present, only a zone of about one square mile in Miami-Dade county is considered to be at risk of active transmission.” Experts in the UK recently urged expectant mothers to avoid travel to the Olympics in Brazil, which has been hit hard by the disease, and parts of the US, including Florida.
There is no treatment or preventive vaccine for Zika. The disease generally produces mild symptoms at worst, such as headache, feverishness and red eyes, and 80% of healthy people who become infected suffer no symptoms. However, the virus has caused Guillain-Barré syndrome in a small number of people in Latin America, and the virus can lead to brain defects in unborn babies, including microcephaly, which leaves babies with abnormally small heads.
The CDC has also warned of probable local outbreaks in other southern coastal states as the summer heats up; poor communities in Texas and Louisiana are seen as particularly vulnerable. Texas reported the first case of Zika transmission in the US in February, believed to have been passed on through sex.