(Bloomberg) -- Miami’s role as the gateway to Latin America has also made it the US epicenter of dengue fever.

Cases of the mosquito-borne illness in Florida have more than doubled this year compared with the same period in 2023, as unsuspecting travelers have carried the virus back from the Caribbean and Southern Hemisphere. Now, authorities are working to keep the disease from infecting the local mosquito population before this summer’s heavy rains turbocharge the risks. 

Florida’s Department of Health has reported 164 cases of dengue since the beginning of the year, with all but six linked to international travel. The US Centers for Disease Control and Prevention shows Miami-Dade as the US hot spot for dengue. 

The spike comes as the virus has exploded throughout the Americas, driven by unusually humid and hot conditions.

The Pan American Health Organization has recorded 3,274 deaths and 7.6 million cases of dengue in Latin America and the Caribbean this year. That’s more cases than it reported in all of 2022 and 2023 combined.

Brazil alone has registered more than 4 million cases and almost 2,000 deaths due to dengue. On Monday, Puerto Rico announced its first dengue-related death, after declaring a health emergency in March.

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Also known as breakbone fever, dengue is carried by certain mosquitoes and can cause debilitating headaches, soreness, fever and rashes. In extreme cases it can be fatal. 

Florida’s cases largely reflect its position at the crossroads of the Americas. Miami International Airport is among the busiest in the US, handling more than 50 million travelers in 2023, almost half of them international travelers. 

When the Miami-Dade County Mosquito Control Division gets wind of a suspected case, it sends out a brigade to spray for larvae and adult mosquitoes, and then goes house to house, eliminating breeding sites near the area, said John-Paul Mutebi, the agency’s director. 

If the suspected infection turns into a confirmed case, the team returns and repeats the operation. In addition, the department has more than 300 traps set around the county and does weekly collections of mosquitoes.

This year’s dengue spike comes earlier than usual and well before Miami’s peak mosquito season in the summer. But it’s too soon to predict what the rest of the year will look like, Mutebi said.

“What is worrying is all the activity we are seeing around us,” he said. “In Puerto Rico you have a state of emergency, and we have no idea what’s happening in places like Cuba or Haiti.”

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