Public health officials are preparing for what seems to many like the inevitable: South Florida’s first locally transmitted case of Zika, a mosquito borne virus that has spread rapidly across Latin America and the Caribbean, and poses the greatest threat to pregnant women and their unborn children.
The health department has confirmed nine cases of Zika virus brought to Florida by international travelers, including four in Miami-Dade County, leading Gov. Rick Scott to declare a public health emergency on Wednesday for the affected counties. A global warning was issued Feb. 1 by the World Health Organization.
No reported cases have originated with a mosquito bite in the continental United States, though the virus has been transmitted through sexual contact in at least one confirmed case in Texas.
With no vaccine or medication available to prevent or treat Zika infections, South Florida hospital physicians are questioning patients in their emergency rooms about recent travel while adhering to guidelines for care from the federal Centers for Disease Control and Prevention.
At the same time, disease detectives and researchers are racing to learn more about the relatively obscure virus.
“There needs to be work done in the laboratory and in the field to understand how this epidemic has come to be and how dangerous is it, really,” said Matthew DeGennaro, a mosquito expert and assistant professor of biology at Florida International University, which hosted a panel discussion on the Zika virus Wednesday in Miami.
There needs to be work done ... to understand how this epidemic has come to be and how dangerous is it.
Matthew DeGennaro, mosquito expert
Without answers to many of their questions about the Zika virus and how it spreads, South Florida residents, particularly pregnant women, said they were at a loss for what to do besides watch and wait — and apply liberal amounts of the insect repellent, DEET.
“At some point, you want to know you’re in the clear. But apparently that’s not possible,” said Monica Flowers of Coral Gables, who is six months pregnant. “We’re so close to Latin America, and we have so many tourists and commerce, sooner or later we’re going to see a case.”
A clinical assistant professor of nursing at FIU, Flowers asked the panel at what stage in her pregnancy Zika posed the least threat, and whether a mother could potentially transmit the virus to her newborn baby through breastfeeding.
The panel had no definitive answers for Flowers, emphasizing how little is actually known about the virus.
Zika symptoms, such as fever, rash, joint pain and red eyes, are similar to other mosquito-borne diseases, such as dengue and chikungunya, but they are not considered life-threatening for most healthy adults, said Aileen Marty, a physician and professor of infectious diseases in FIU’s Wertheim College of Medicine.
But Zika’s possible association with clusters of microcephaly, a congenital brain defect, and other neurological disorders among newborns in some areas affected by the virus — notably in Brazil since May 2015, and in French Polynesia in 2014 — triggered alarms of a global health crisis.
Zika virus outbreaks have occurred in areas of Africa, Southeast Asia and the Pacific Islands. In May 2015, the Pan American Health Organization issued an alert regarding the first confirmed Zika virus infections in Brazil.
In 2014, when epidemiologists believe Zika arrived in Brazil, the country recorded 147 microcephaly cases, said Tomás Guilarte, dean of FIU’s Stempel College of Public Health. Since October, Brazil has reported about 4,200 suspected microcephaly cases and the deaths of 70 babies associated with the virus.
Still, scientists have “no concrete proof that the virus is causing microcephaly,” DeGennaro said, adding that there are more questions than answers about Zika, such as how it has evolved since the first recording in 1949, and whether outbreaks are related to environmentally favorable conditions, such as heat, rainfall and humidity, or to climate changes, such as increased rainfall and warming.
Adding to the complexity is the broad range of effects the virus can have on those it infects, said Consuelo Beck-Sagué, a pediatrician and assistant professor of public health at FIU.
About one in five people infected with the virus become ill, according to the CDC. Similarly, said Beck-Sagué: “There were a lot of babies born in Brazil without microcephaly who clearly had perinatal exposure and prenatal exposure [to the Zika virus].”
While scientists work to learn more about the virus, DeGennaro said an epidemic outbreak like the one in Brazil remains less likely in South Florida, where housing and socio-economic conditions act as barriers to infection.
30 Countries and territories to which travel is not advised by the Centers for Disease Control and Prevention.
“One of the things that makes us in Florida a little bit safer is that we have much better mosquito control mechanisms,” he said. “We live in homes that have screens and have air conditioning. . . . We kind of prevent access of the mosquitoes to people in ways that are not happening in, let’s say, Northeast Brazil, where people are a lot more impoverished.”
Still, noted Marty, the infectious disease expert, the mosquito that transmits Zika, known as Aedes aegypti, is “a day biter” and tends to feed when people are more likely to be outdoors.
South Florida, with its warm, humid climate and reliable rainfall, is one of the few states in the nation where Aedes aegypti feels at home, DeGennaro said. And scientists are employing new methods, including genetically modified mosquitoes, to combat the insects’ spread.
“This is the world’s deadliest animal,” he said, noting the insect’s ability to spread diseases such as yellow fever and malaria. “It is responsible for 725,000 deaths a year.”
His best advice for those concerned about how to protect themselves against Zika virus: