Florida health officials have issued a mosquito alert after two locally acquired cases of dengue fever were confirmed in the Florida Keys.

The alert comes a week after a national health advisory by the U.S. Centers for Disease Control and Prevention (CDC), warning health care providers and the public of rising cases of dengue fever infections in the Americas.

Dengue fever is a viral infection spread by mosquitoes. The virus is thought to infect up to 400 million people every year, according to the World Health Organization, resulting in as many as 40,000 annual deaths. The disease is characterized by a high fever, often combined with aches and pains, nausea and vomiting, which can range from mild to severe (although typically only last two to seven days.)

Only about 1 in 4 people infected with dengue actually get sick and symptoms tend to develop within two weeks of getting bitten.

The disease is mostly found in tropical and subtropical climates, although local transmission has historically been reported in Florida, Texas, Arizona and California.

At the end of June, two locally acquired dengue cases were confirmed in Monroe County, bringing Florida’s total local case count to 10 since the start of 2024. So which other counties have seen confirmed local dengue cases?

This year, Miami-Dade has seen the highest number of locally acquired infections, with two in January, one in February, two in March and one in April. Hillsborough and Pasco have also seen one confirmed case each, in June and January, respectively.

While these case numbers are still very low, the Department of Health for Monroe County and Florida Keys Mosquito Control District are coordinating surveillance and prevention efforts to curb transmission in the region. These include door-to-door surveillance and mosquito-targeted insecticide spraying from trucks and the air where necessary.

The Florida Department of Health also recommend the following measures to protect yourself from mosquitoes:

• Apply insect repellents to skin and clothing (some may not be suitable for children so always read the label).
• Remove or cover any pools of standing water in which mosquitoes could breed, including in buckets, roof gutters, rain barrels, old tires and birdbaths. Even just a bottle cap of standing water is enough for mosquitoes to breed and multiply.
• Use air conditioning and window screens to keep the insects outside.

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