How Zika spreads (and who’s to blame)
Florida health officials confirmed three new Zika virus infections on Tuesday, including one pregnant woman and one new case in Miami-Dade, as U.S. Sen. Bill Nelson, a Democrat, held a press conference in Coral Gables urging Congress to fund a $1.9 billion emergency appropriation requested by President Barack Obama to combat the disease.
Zika virus has impacted Florida more than any other state, with a total of 102 people affected since February, including at least 40 in Miami-Dade, the county with the most cases. Included in the statewide total are seven pregnant women, though the health department does not disclose their counties of residence because of privacy concerns.
With Zika cases on the rise and the rainy season at South Florida’s doorstep, Nelson called a media conference with University of Miami Health System infectious disease experts and a Miami-Dade mosquito control manager to press Congress for additional funding.
Congress has been sitting on President Obama’s request since February. Nelson said federal, state and local officials need the emergency funding to pay for mosquito control efforts, scientific research into the disease and the development of a vaccine, medical care for those infected, and educational materials for the public.
“We are looking at a full-blown crisis,” said Nelson, who is the lead sponsor of Senate legislation to fund the president’s emergency request. “This is as much an emergency as a hurricane and the Ebola virus.”
Republican congressmen, including Sen. Marco Rubio and Rep. Vern Buchanan, both Florida Republicans, have said they support the president’s efforts for additional Zika funding.
Seated in a conference room across the hall from his Coral Gables office, Nelson was joined by Chalmers Vasquez, mosquito control operations manager for Miami-Dade, and researchers from UHealth, including Mario Stevenson, chief of the division of infectious diseases, and José Szapocznik, chair of the department of public health sciences.
Vasquez said there are 48 different species of mosquitoes known to inhabit Miami-Dade, but that the county controls for about half of those, including Aedes aegypti and Aedes albopictus, which are known to transmit the Zika virus.
He said most local mosquitoes originate from Everglades National Park, and that given the federal protections afforded the River of Grass it is not possible for the county to order spraying of the area for the insects.
“They want to keep that area as pristine as possible,” Vasquez said of federal parks officials.
Still, said UHealth’s Szapocznik, “Fumigation by air looks good but it’s least effective.”
He said that once local transmission of Zika begins, it will be very difficult for public officials to control mosquitoes without using other methods, such as irradiation and sterilization of males, release of genetically modified mosquitoes or the use of an anti-Zika bacteria called Wolbachia.
“All these things take time,” Szapocznik said. “Will we have Wolbachia ready in case of an outbreak?”
Short of a vaccine or highly effective mosquito control efforts, Stevenson emphasized public education efforts and he urged South Florida residents to use insect repellant, wear long sleeves and take other protective measures to avoid getting bitten by the insects.
“It’s not really that complicated in terms of how you protect yourself,” he said.
Stevenson, who recently returned from a trip to Brazil, said researchers are working to create a body of scientific publications that will inform public health efforts against the disease. He said there are just over 660 published works related to Zika in comparison to more than 300,000 published works on the HIV virus.
“We’re having to create the knowledge base,” he said. “With no funding, there is no development of the knowledge base.”
Researchers have made progress in recent months, however, particularly in understanding how Zika affects a pregnant woman and her unborn child. There’s now a conclusive link between the virus and congenital microcephaly, a condition in which a newborn’s head is smaller than expected, which can lead to developmental issues.
The CDC recommends that women who are pregnant or thinking of becoming pregnant postpone travel to affected areas where Zika is locally transmitted, including much of Latin America and the Caribbean.
Nearly all of Florida’s cases were acquired by people traveling outside the country, except for one case of sexual transmission in Polk County.
Zika cases in Florida as of May 3
Number of Cases
Cases involving pregnant women*
* Counties of pregnant women are not disclosed.
Source: Florida Department of Health