Mosquito expert available to discuss Florida's dengue fever outbreak

Florida is experiencing one of its most significant dengue fever outbreaks in years, with case numbers rising statewide and the state's first virus-related death confirmed by the Florida Department of Health in early September.

"It's one of the worst years for dengue that Florida has had in some time," said Tulane University medical entomologist Dawn Wesson. "They'll have a few locally transmitted cases most years, but not this many. It's also a little unique in that it's further north than where most previous outbreaks have hit, which tend to be closer to the Miami-Dade area."

Wesson, who directs Tulane's Vector-Borne Infectious Disease Initiative and has studied dengue and other vector-borne viruses for more than three decades, said the outbreak is being driven by a combination of climate and human travel that allow Aedes mosquitoes to thrive and spread the virus.

"Part of it is climate," said Wesson, associate professor of tropical medicine at Tulane’s Celia Scott Weatherhead School of Public Health and Tropical Medicine. "But it's also that people travel all over the world, and people coming into airports like Miami disperse into the surrounding area, and some of them are infected with dengue. They bring the virus in and set off local transmission.”

Two Aedes species spread dengue: Aedes aegypti, the primary vector, which originated in Africa, and Aedes albopictus, the Tiger mosquito, native to Southeast Asia, which is believed to have arrived in the U.S. in the mid-1980s in shipments of used scrap tires. Unlike many mosquitoes found in the U.S., Aedes bite during the day and are recognizable by their black-and-white banded markings. They lay their eggs in natural containers like tree holes as well as man-made ones such as tires.

“Tires tend to be a real problem for all these container-inhabiting mosquitoes,” Wesson added.

Wesson said the mosquitoes are especially difficult to control and current tools remain limited. Medical entomologists like Wesson are pursuing ways to kill them outright or alter them genetically or bacterially so they can't transmit the virus as well.

"That's the kind of stuff that keeps me up at night and keeps me busy," Wesson said.

Wesson has traveled the world researching new tools to fight dengue, including projects in South America, and has served in advisory roles with local parish and regional mosquito control boards.

For everyday protection from mosquitoes, Wesson recommends DEET-based repellent as well as long sleeves and a hat.

Dengue outbreaks are also surging elsewhere in the world, including a major outbreak currently ongoing in Bangladesh. In the U.S., locally acquired dengue cases have also been reported in Hawaii, Texas, California and Arizona in past years.

To schedule an interview, please contact Addison DeHaven, assistant director of media relations at Tulane University, at adehaven@tulane.edu or 605-651-2567.