The Zika virus, which raced across Latin America and the Caribbean this year, is no longer a global health emergency, the World Health Organization said Friday.
The emergency is over because researchers have a better understanding of the virus — and can manage it like other "important infectious diseases," said Dr. David Heymann, chairman of the agency's Zika Emergency Committee.
"The emergency committee felt the Zika virus and associated complications remain a significant and an enduring public health challenge," Heymann said. ". . . But it no longer represents a public health emergency of international concern."
Zika has remained a stubborn problem in Florida. Statewide, the number of locally acquired cases has ballooned to 234, according to the Florida Department of Health. The number of travel-related cases tops 930.
"We are not out of the woods yet," said Dr. Beata Casanas, associate professor in the infectious disease division at the University of South Florida's Morsani College of Medicine.
Zika gained international notoriety this year because of its potentially devastating consequences. Only a small fraction of people who contract the mosquito-borne virus show symptoms. But it can cause serious defects in unborn children.
In Brazil alone, more than 2,000 babies were born with microcephaly, a condition characterized by brain damage and a small, underdeveloped head.
Epidemiologists predicted Zika would spread from Latin America to Florida; the species of mosquito that carries the virus thrives in the state's warm climate.
The outbreaks, however, have been largely limited to South Florida. All but one of the locally acquired cases and more than half of the travel-related cases have been reported in Miami-Dade, Broward and Palm Beach counties.
Ira Longini, a biostatistics professor at the University of Florida who published Zika projections in August, said the models for Florida were "pretty much right on target."
His latest model predicts a total of 282 locally acquired cases through Dec. 15. He expects local transmission to continue in South Florida until the daytime temperatures dip into the low 70s and mosquitoes start to slow down.
"Unless there is a cold snap, that could be some time," he said.
Many public health officials, including Centers for Disease Control and Prevention director Tom Frieden, said they believe the Zika virus will become endemic, meaning it will stay in the population at low levels and flare up on occasion.
If that's the case, Florida should consider some longer-term strategies, said Chris Uejio, a geography and public health professor at Florida State University.
"We could continue our reactive public health system that's focused on putting out short-term fires," Uejio said. "Or we could build the capacity for sustained mosquito control and public health surveillance efforts."
Researchers are also continuing to work on vaccines that could be used to prevent Zika. The National Institutes of Health, for example, has launched a clinical trial of a vaccine that can help the body create Zika virus proteins. Scientists hope to begin the next phase of research early next year.
Vaccines aren't the only approach. Florida State researchers, working in collaboration with scientists from Johns Hopkins University and the NIH, have identified molecular compounds that can stop Zika from replicating in the body, FSU professor Hengli Tang said.
"Those potentially could be developed into therapeutics to treat the Zika infection," he said.
Tang said some of the compounds already have been approved by the FDA to treat other diseases. Still, he and his team must conduct trials to determine the proper dosage and schedule. They are currently preparing to test some of the compounds in animals, he said.
Meanwhile, health officials say pregnant women in Florida should continue taking precautionary measures. That means wearing long sleeves and pants whenever possible, and applying bug spray before going outside.
They should also refrain from traveling to countries that have struggled with the virus, said Casanas, the USF professor.
"It's important to remain vigilant," she said.
Contact Kathleen McGrory at [email protected] or (727) 893-8330. Follow @kmcgrory.