Pregnant women and those hoping to become pregnant have been warned to stay away from one square mile of Miami, Florida, following the diagnosis of 14 cases of Zika virus infection caused by the bites of local mosquitoes.
Florida’s governor, Rick Scott, assured vacationers and other visitors that Miami was safe and open for business, in a robust statement designed to bolster the state’s huge tourism industry. Florida has already welcomed 30 million tourists this year, said Scott, and thousands more are arriving for the summer holidays every day.
But the federal Centers for Disease Control and Prevention put out the warning after Scott asked the CDC to activate an emergency response team to help in controlling mosquitoes. It said Miami’s mosquito control efforts were not working as well as had been hoped and that pregnant women should avoid travel to the Miami area affected by local transmission of zika virus.
The CDC also said that pregnant women who travelled to the affected area on or after 15 June should be tested for Zika virus. The Florida infections are thought to have occurred in a small area just north of downtown Miami, in the Wynwood arts district. The area, known for murals spray-painted across warehouses, art galleries, restaurants and boutiques, is rapidly gentrifying, but it has a number of construction sites where standing water can collect and serve as a breeding ground for mosquitoes.
In a statement, Scott played up the successes of the past against mosquito-borne diseases. “We will continue to keep our residents and visitors safe, utilizing constant surveillance and aggressive strategies, such as increased mosquito spraying, that have allowed our state to fight similar viruses,” he said.
Four people were confirmed with Zika virus acquired from local mosquitoes on Friday. A further 10 cases were confirmed on Monday as a result of the door-to-door testing that has been going on in three locations in Miami-Dade and Broward counties since reports of transmissions in the state in early July. Some 200 people have been tested and two of the three locations have been ruled out.
Twelve of those infected are men and two are women. Six had no idea they were infected with the virus, because they had no symptoms. Zika infection is normally very mild and any symptoms disappear in a few days. Very rarely and like a number of other viruses, it causes Guillain-Barré syndrome in adults, which is characterised by weakening of the muscles and some paralysis but in most cases gets better over time.
But the real worry is over the effects of Zika virus on the foetus of a pregnant woman, which has caused the World Health Organisation to declare an international emergency. It can cause an abnormally small head (microcephaly) and other forms of brain damage. So far, by far the greatest number of reported cases – about 1,750 – have been in Brazil.
More than 1,650 people have returned from Latin America to the United States with Zika infection or – rarely – picked it up through sex with somebody who has travelled there. But the four cases confirmed on Friday were thought to be the first in which transmission occurred within the US. Transmission is through the bite of the Aedes aegypti mosquito, which flourishes in the warm, wet Florida climate.
US health officials do not expect the sort of outbreak seen in Latin America, which is worst in the north-east region of Pernambuco, in areas of favelas with poor sanitation and shanty homes without nets or screens at the windows, where there is standing water in rubble-strewn paths and people cannot afford insect repellent.
Florida has been taking aggressive action against mosquitoes for the last few weeks, spraying and trapping insects. Both the CDC and the White House have praised Florida’s response to mosquito-borne infections in the past. Cases of both chikungunya and dengue fever – viral infections from the same family – arrived in the state, but the number of infections caused by local transmission from the bite of infected Aedes aegypti mosquitos was kept low. Zika, however, poses such a serious threat to pregnant women that some thought Scott should have called in the CDC team earlier.
