The CDC has confirmed reports of active Zika transmission in the Miami Beach area of Florida, and has issued updated travel guidance for that particular area.
The area encompasses 1.5 square miles, between 8th and 28th streets of Miami Beach. This is the second cluster of cases in Florida where mosquito-borne transmission appears to be ongoing, and not just isolated cases.
Pregnant women should now avoid travel to the area of Miami Beach, similar to the guidance already issued for the Wynwood area north of Miami (both in Miami-Dade County). The CDC is also recommending that pregnant women who have traveled to or live in this area of Miami Beach since July 14, 2016 should be tested for Zika virus, and engage in appropriate precautions for the duration of pregnancy.
According to a statement issued by the state of Florida, 36 cases of local Zika virus transmission have been identified in the state.
"Following today's news, I am asking the CDC for an additional 5,000 Zika antibody test kits to ensure we can quickly test people for the virus and additional lab support personnel to help us expedite Zika testing," said Florida Gov. Rick Scott (R) in a statement. "Also, to continue protecting pregnant women, I am renewing my call to the Obama Administration for an additional 10,000 Zika prevention kits."
But the CDC noted in a press release that it has been difficult to detect local spread of Zika, because the incubation period can be up to two weeks, with diagnosis and investigation of cases taking several weeks -- as well as that a large portion of people with Zika virus appear asymptomatic.
CDC director, , also warned that this is not over. "We're in the midst of mosquito season and expect more Zika infections in the days and months to come," said Frieden in a statement. "It is difficult to predict how long active transmission will continue. Florida and Miami-Dade County are taking appropriate steps to control mosquitoes and protect pregnant women."
The organization acknowledged that it is possible other neighborhoods in Miami-Dade County may also have local Zika transmission -- investigators have been probing cases in several areas outside the Wynwood district -- but this has not been confirmed.
In addition to the two clusters in Wynwood and Miami Beach, there have also been isolated cases identified in the Miami-Dade County area. The CDC is recommending that pregnant women and their partners who may be concerned about Zika virus may consider postponing travel to Miami-Dade County entirely.
"There have been multiple instances of indidivudal transmission in an area with more than 2 million residents and more than 20,000 pregnant women," said Frieden during a conference call with reporters. "That's why we've highlighted that while we're quite concerned about these two areas, we're mentioning the fact that there have been isolated cases throughout Miami-Dade County."
Mosquito control may also be more difficult in Miami Beach, where the many high-rise buildings prevent aerial spraying. Frieden said that aerial spraying in the Wynwood area has been more successful, but it has been extraordinarily difficult to eliminate what he characterized as "the cockroach of mosquitoes."
"So far, what we're seeing is what we anticipated -- multiple individual instances and some cases of clusters," said Frieden.