Phil Goodman’s job has become more challenging in recent years. The retired chemical company president chairs the Florida Keys Mosquito Control District Board of Commissioners, and mosquito-borne diseases — once almost eradicated in Florida — have been on the rise.
Last year, seven people in Sarasota County came down with malaria, marking the first time in 20 years that anyone in Florida had contracted the virus locally. Dengue has been making a comeback too. In 2023, there were 172 cases of locally acquired dengue in Florida and through the end of August 2024, 29 dengue infections were reported in six counties, including three in the Keys.
At the same time, new mosquito-borne viruses are hitching a ride into the state via international visitors.
“Oropouche — that’s a new one that’s going around now, mainly coming from Cuba, Brazil and Colombia,” Goodman tells me. At press time, there were 32 travel-related cases in Florida. Nicknamed “sloth fever” after one of the rainforest animals the virus is believed to have originated in, Oropouche (pronounced Oar-a-poosh) also is spread by small flies known as midges. It presents with an array of unpleasant symptoms including sudden fever, headache and chills. Though cases are typically mild, there are indications it’s becoming more menacing. Amid a surge of the disease this past summer, Brazil reported the world’s first deaths from Oropouche of two women, aged 21 and 24, who were otherwise healthy. The disease has also been linked to fetal deaths and birth defects.
Goodman doesn’t expect Oropouche to become a problem in the Keys, but it’s yet another mosquito-transmitted virus — along with West Nile, eastern equine encephalitis, chikungunya and Zika, to name a few — that he’s keeping on his radar.
It’s dengue, though, that has him worried. Also known as “break-bone fever” for the excruciating pain it causes, dengue hasn’t been endemic in the U.S. since the 1940s. “It was sort of eliminated here with DDT. It was eliminated for a lot of the world,” Goodman says, but the uptick in cases signals an inflection point in Florida’s long-running war on mosquitos. For decades, he notes, Florida mosquito control efforts have been focused on nuisance control and comfort — but disease control has returned to the forefront.
Several factors are contributing to the growing threat. Among them, Aedes aegypti mosquitos, which are more likely to carry dengue and other viruses, have grown increasingly resistant to the best pesticides available. Climate change too is fueling the pest’s activity. “We see it here in the Keys. Our sea level is definitely rising. [With] more water, they are more prolific here than ever,” Goodman says. So-called “mosquito days” also are on the rise. Florida’s mosquito season — measured by the number of days where humidity and temperature are optimal for the critters to thrive and bite — is now 10 days longer now on average than it was from 1980 to 2009, according to a recent Washington Post analysis.
The good news in all of this, if you can call it that, is that folks like Goodman are pursuing new, groundbreaking methods of mosquito control.
Among the most promising is the genetically engineered Aedes aegypti mosquito known as OX5034. Bred by the British biotechnology company Oxitec, the non-biting, male mosquito has been altered to carry what’s known as a self-limiting gene.
Here’s how it works: Boxes containing OX5034 eggs are deposited in known Aedes aegypti hotspots. Once water is added, the eggs hatch into larvae, but only the males survive. Those male skeeters mate with wild females, passing along the gene that kills any female offspring before they reach maturity. With fewer female mosquitos in those regions, the population goes into decline.
The Florida Keys Mosquito Control District conducted three releases of about 12 million OX5034s through an Oxitec pilot project conducted in 2022 and 2023. Goodman says the experimental release went well, and the Aedes aegypti population in the targeted regions declined as predicted. While data from the pilot project is now in the hands of the Environmental Protection Agency, Goodman is hopeful the Oxitec mosquitos might be approved in time for the 2025 mosquito season. Used in combination with insecticides, he suspects they might be able to move from 50-60% eradication of Aedes aegypti populations to about 90% — effectively delivering a sucker punch to the blood-sucking insects.
In the meantime, the Keys’ team of inspectors — like many across the state — will carry on, going door to door, mangrove to mangrove, collecting mosquitos so they can be identified and counted. They’ll respond to thousands of service calls and visit homes and schools, teaching residents that Aedes aegypti’s favorite place to lay her eggs is in the empty flowerpot or dog bowl left in the yard — and that by dumping standing water at least once a week, we can all help reduce risks. When a mosquito hotspot is detected, they’ll dispatch spray trucks and choppers to target the blood suckers. They’ll take a reporter’s call on a moment’s notice, help out a fellow county when needed, and carry on with their work, day in, day out, year after year, like your life depends on it — because it just might.
— Amy Keller, Executive Editor akeller@floridatrend.com