Dengue fever confirmed in Florida Keys as US on watch for rise in mosquito illness

Two people have fallen ill with dengue fever in the Florida Keys after being bit by infected mosquitoes, prompting health officials to issue an alert for the island chain.

The alert comes just days after the U.S. Centers for Disease Control and Prevention issued a health advisory warning of an increased risk of dengue infections in the country as cases surge globally.

Dengue fever can cause flu-like symptoms “with severe muscle aches and joint pain, fever, and sometimes a rash,” according to the Florida Department of Health in Monroe County. Aedes aegypti mosquitoes spread dengue to people through bites.

The two confirmed dengue cases in the Keys were locally acquired, according to the mosquito-born illness alert issued Saturday by the health department. That means the infections are not associated with travel.

Miami-Dade, Pasco and Hillsborough counties have also reported locally acquired dengue cases this year, state data shows.

Dengue is not contagious and can only spread to people by bites from infected mosquitoes.

Monroe health officials say they’re working with the Florida Keys Mosquito Control District to coordinate surveillance and prevention along the island chain. That includes more trapping and monitoring of mosquitoes, intensifying door-to-door mosquito inspections, and deploying aerial and truck-mounted mosquito spraying.

People are urged to take precautions, including draining and covering still water and using EPA-registered mosquito repellents, to reduce getting bit by the bloodsuckers.

Dengue infection risk rises in US, CDC says

The dengue cases in the Keys come just days after the CDC issued a health advisory alerting health care providers and public health officials of an increased risk of dengue infections in the country this year. There’s been a record number of dengue cases globally this year, and the illness has surged in Latin American countries, with more than 9.7 million dengue cases reported so far in 2024, according to the CDC. That’s twice as many cases as in 2023.

Sweltering temperatures, stronger storms and “more erratic and frequent rainfall” are “contributing to outbreaks of mosquito-borne illnesses around the world,” according to Yale Climate Connections. These “warmer winters, hotter summers, and particularly milder springs and falls” are helping the Aedes aegypti mosquito, the species that spreads dengue, “to move into new areas and higher elevations that have historically been too harsh for their survival.”

And the U.S. has already seen more dengue cases then expected this year, with 2,241 cases reported from January through June 24, according to the CDC advisory. More then half of the cases were in Puerto Rico, which declared a public health emergency in March after seeing a rise in dengue infections during its low dengue season. Dr. Carlos Mellado López, the secretary of the Puerto Rico Department of Health, said dengue cases had “surpassed historical figures.”

In Florida, there has been more than 200 dengue cases reported this year, but nearly all are associated with international travel, state data shows. If you count the new cases in the Keys, at least 10 locally acquired dengue cases have been identified in the state this year. Six of the cases were reported in Miami-Dade County, which has been under a mosquito-borne illness alert since last year.

Most people infected with dengue don’t get symptoms, and many recover within a week, according to the Mayo Clinic. But some do get seriously ill and die. People with severe cases of dengue fever can experience severe stomach pain, persistent vomiting, difficulty or rapid breathing, internal bleeding, and organ failure, according to the Mayo Clinic.

The CDC has issued multiple travel health notices related to mosquito-borne diseases such as dengue, yellow fever and oropouche, including for Colombia, Cuba, Costa Rica, Nicaragua, Guatemala, Mexico, Peru, Nigeria and Argentina.

The federal public health agency said it’s expanding laboratory capacity to improve testing for dengue and is urging doctors to “have increased suspicion of dengue” in patients who have fever and had recently traveled (within 14 days before feeling ill) to areas with “frequent or continuous” cases of dengue.

2024 Miami Herald. Distributed by Tribune Content Agency, LLC.