Second Zika Zone in Florida Prompts CDC Travel Warning


August 19, 2016

Pregnant women should avoid traveling to a section of Miami Beach in Miami, Florida, that's been identified as the second area in the state where mosquitos are spreading the Zika virus, the Centers for Disease Control and Prevention (CDC) announced today.

In addition, pregnant women and their sexual partners who worry about exposure to the Zika virus, which can cause microcephaly and other birth defects, may consider postponing nonessential travel to all parts of Miami-Dade County, the agency said in a news release.

The virus is not necessarily spreading throughout the entire county, said CDC Director Tom Frieden, MD, MPH, in a news conference today, but there have been instances of mosquitos infecting individuals here and there outside the new Miami Beach zone as well as a 1-square-mile section of the Wynwood neighborhood just north of downtown Miami. In those two areas, the Florida Department of Health (DOH) has uncovered clusters of cases representing ongoing transmission. Outside of those areas, isolated cases involving local transmission have not triggered chain reactions, or at least not yet, said Dr Frieden.

"We will always err on the side of providing more information to the public so people can make more informed decisions…to protect themselves," said Dr Frieden, explaining the decision to offer advice to pregnant women about visiting Miami-Dade County.

The CDC issued a travel advisory, still in effect, on August 1 for the Wynwood Zika zone after the Florida DOH said that infected mosquitos were biting people there. However, this advisory did not extend in any way to the rest of the county.

Florida is the only state so far to report local transmission of the Zika virus.

In a news conference today, Florida Governor Rick Scott said the second Zika zone covers less than 1.5 square miles in Miami's South Beach neighborhood. It extends from 8th Street to 28th Street and from the beach to the Intracoastal Waterway. Five cases of Zika infection are linked to this area so far.

As of today, the Florida DOH counted 36 individuals in the state who've become infected through local transmission and 488 individuals whose infections stemmed from traveling outside the country to an area of mosquito-borne transmission or from having sex with such a traveler. Of all the individuals with Zika, 68 are pregnant women.

Long-sleeve Shirts on Miami Beach?

The CDC's Dr Frieden acknowledged today that quelling the Zika outbreak in Miami Beach presents special challenges.

For one thing, the state of Florida can't spray Miami Beach mosquitos with insecticide from the air as it's done in the Wynwood zone. Aerial spraying requires planes to fly just 100 feet off the ground, and the high-rises on Miami Beach preclude that, Dr Frieden said. The only alternative is a ground game, such as backpack spraying.

Also, the standard advice to wear long pants and long-sleeve shirts to avoid mosquito bites doesn't make sense for people who come to the beach in their bathing suits to enjoy the sand, surf, and sun. "Exposed skin makes it difficult," he said, but added that beachgoers can still protect themselves by spraying on the insect repellent DEET.

Finally, the South Beach neighborhood teems with tourists, creating "a high turnover" of people who can be newly exposed to the virus. Of the five individuals who contracted the infection there, three were travelers — one from New York, one from Texas, and one from Taiwan.

Updated Guidance for Caring for Infants of Possibly Infected Mothers

In another response to the outbreaks in the United States, the CDC today issued updated guidance on how to care for infants whose mothers may have been infected with Zika during their pregnancy.

For example, the CDC previously had advised performing a cranial ultrasound on such an infant unless prenatal ultrasound results from the third trimester failed to find any brain abnormalities. Now the agency is recommending cranial ultrasounds regardless of normal prenatal findings. Also, clinicians should no longer test blood specimens from a newborn's umbilical cord for evidence of infection because, if contaminated by maternal blood, they may yield false positives. False negatives are possible, too.

The updated guidance appears in the agency's Morbidity and Mortality Weekly Report.

Follow Robert Lowes on Twitter @LowesRobert


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