By Steven Reinberg
FRIDAY, Oct. 14, 2016 (HealthDay News) -- A new Zika zone was declared Thursday by Florida health officials, only weeks after a nearby neighborhood was cleared of the mosquito-borne virus following aggressive aerial spraying of insecticides.
The new area is roughly three miles north of Wynwood in Miami, where the first local outbreak of Zika occurred. Five people -- two women and three men -- have been infected so far, according to the Florida Department of Health. Three are local residents, while the other two visited or worked there.
Florida now has three areas where Zika has been spread locally, although Wynwood is no longer considered an active transmission zone. A section of Miami Beach is the third Zika area.
"We have had more than 1,000 cases of Zika [travel-related and local] in our state, and Miami-Dade County continues to be the only area with ongoing active transmissions," Gov. Rick Scott said in a statement.
"I have continued to provide state funding to Miami-Dade County and this week, I allocated an additional $7 million for the county to fight mosquitoes," Scott added. "We have seen that aggressive mosquito control efforts have worked in areas like Wynwood and we hope the county also aggressively sprays in this area so we can limit the spread of this virus and protect pregnant women and their growing babies."
In response to the latest setback in Florida, officials from the U.S. Centers for Disease Control and Prevention said Thursday that pregnant women should avoid traveling to the new Zika zone, and they should consider postponing non-essential travel to the rest of Miami Dade.
In clearing the Wynwood neighborhood of Zika, a combination of insecticides was needed to beat back the Aedes aegypti mosquito that carries the virus, state and health officials have said.
While ground spraying was ineffective, aerial spraying with the insecticides naled and Bti (bacillus Thuringensis) dramatically reduced the mosquito population and local transmission of Zika, CDC Director Dr. Tom Frieden said at the time.
"This really heralds in a new era of [mosquito] control," Frieden said. "It appears that the aerial application of the one-two punch has the ability to rapidly interrupt transmission. It doesn't mean that the area is immune from future spread, but the findings are quite striking," he added.
These pesticides kill both the insect and its larvae, preventing the birth of new mosquitoes, Frieden said.
Aerial spraying is part of a comprehensive mosquito-control program that also includes encouraging people to get rid of standing water on their property and protect themselves against mosquito bites as well as using ground spraying in hard-to-reach areas, Frieden said.
This breed of mosquito has been particularly hard to control, Frieden said. And it's impossible to know if spraying will work in the long run, he added. But after spraying, the mosquito population in the Miami area dropped significantly, as evidenced by the low numbers of insects found in mosquito traps, he said.
The Zika epidemic has been centered in Latin America and the Caribbean, with Brazil reporting the largest numbers of infections and the birth defect microcephaly, which causes babies to be born with extremely small heads and underdeveloped brains.
To reduce the risk of local Zika transmission within the United States, the CDC recommends that people returning from places with ongoing infections should use mosquito repellent every day for three weeks and follow the CDC's guidelines to prevent sexual transmission of Zika.
The Zika virus doesn't pose a significant health threat to most people, except pregnant women and fetuses.
The virus can be spread by infected men and women to their sex partners. There is no vaccine or treatment for Zika.
The CDC advises that partners of pregnant women use a condom to guard against sexual transmission during pregnancy.