Dengue fever on the rise. What to know about the mosquito-borne illness in Florida

MIAMI — The U.S. is on alert for dengue fever during the busy spring break season as cases of the mosquito-borne illness continue to rise globally.

Puerto Rico, the U.S. Virgin Islands, Cuba, Colombia, and Mexico are some of the places that have seen a rise in dengue cases, an illness that is known to cause flu-like symptoms, including fever, severe muscle aches, and sometimes, a rash.

Infected female aedes aegypti mosquitoes spread dengue to people through bites. And some parts of the U.S. are home to the pesky insects, including Florida.

“Globally, dengue cases have increased substantially in the last 5 years, with the most pronounced increases occurring in the Americas,” which last year reported record-breaking number of infections, according to the U.S. Centers for Disease Control and Prevention.

So far, more than 760,000 dengue cases have been recorded in 2025, with “many countries reporting higher-than-usual number of dengue cases in 2024 and 2025,” the CDC said this week in a health update. Dengue activity also “remains high” in some parts of the U.S, including Puerto Rico and the U.S. Virgin Islands, which are battling ongoing dengue outbreaks.

The federal health agency is asking doctors to monitor for possible dengue symptoms in patients who were recently in areas known to have cases of dengue and to also “take a thorough travel history” of patients with sudden fever. The CDC is also recommending doctors “advise patients who plan to travel to take steps to prevent mosquito bites during travel and for 3 weeks after returning, especially if traveling to an area with frequent or continuous dengue transmission.”

Are there dengue cases in Florida and other popular spring break destinations?

This year, the U.S. has recorded more than 1,150 cases of dengue, most of which were reported in Puerto Rico, which declared a public health emergency over the mosquito-borne illness in early 2024, according to the CDC.

Puerto Rico has recorded at least 1,012 cases of dengue so far in 2025, followed by Florida, 50, and the U.S. Virgin Islands, which has recorded 40 cases, federal and state data shows.

Where are the dengue cases coming from?

Dengue is a common mosquito-borne illness in many countries, including the Americas, Africa, the Middle East, Asia and the Pacific Islands, according to the CDC. And the federal public health agency says its detected higher case counts or “higher-than-expected number of dengue cases” among U.S. travelers returning from several countries, including Cuba, Colombia, Panama, Brazil and Mexico.

In Florida, which has recorded 50 dengue cases this year, all but one are considered travel-related, which means the person traveled to a “dengue-endemic area” in the two weeks prior to experiencing symptoms, state data shows. And more than half of the state’s recorded dengue cases involve Miami-Dade residents who had recently traveled elsewhere.

Most Floridians who got sick with dengue this year had recently traveled to Cuba, according to the state’s most recent surveillance report. In February, Miami-Dade also recorded the state’s only confirmed “locally acquired” dengue case for 2025.

The CDC, in its health update, said it expects the U.S. will see an increase risk for travel-related and locally acquired dengue cases in the coming months due to spring and summer travel coinciding “with the peak season for dengue in many countries.”

In Miami-Dade County, for example, mosquito season mirrors hurricane season, and runs from June through November, Dr. John-Paul Mutebi, division director of Miami-Dade’s Mosquito Control, previously told the Miami Herald.

Here’s what else to know:

Can you get sick from any mosquito bite?

Mosquitoes are common year-round in Florida. But not all of them can get you sick.

Some of them are annoying pests. Others can carry disease like dengue, West Nile and Zika.

Of the 49 known species in Miami-Dade County, only a few are considered nuisances to humans, according to mosquito inspectors. One of the species that concerns county officials most is Aedes aegypti, or yellow fever mosquito, which can be found across Miami-Dade and can spread Zika, dengue and yellow fever.

What are dengue fever symptoms?

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.

“Symptoms appear 3-14 days after the bite of an infected mosquito and include sudden onset of fever, severe headache, eye pain, muscle and joint pain,” and bleeding, according to the Florida Department of Health. Some people may also experience vomiting and diarrhea.

The only way to know if you’re sick with dengue is to get tested.

How can you treat it?

The good news is that unlike the flu, dengue is not contagious and can only spread to people by bites from infected mosquitoes. The bad news is that there’s no specific treatment for dengue fever.

If you do get sick with dengue, the CDC recommends resting as much as possible, staying hydrated and take acetaminophen (Tylenol) to help with fever. Avoid taking “ibuprofen (Advil) or aspirin because because they may cause bleeding in more severe cases,” as the Herald has previously reported.

Tips to reduce your risk of dengue infection

The best way to reduce your risk of dengue infection is to avoid being bit by the pesky bloodsuckers:

Here are tips:

▪ Wear EPA-approved long-sleeve shirts if planning to be outside. And wear pants and socks, too. This may sound blasphemous, especially for those who want to get a tan or were planning to have a “hot girl summer.” But if you want to reduce a risk of a bite, leave the shorts, tanks and sandals at home. And make sure to drink lots of water and avoid being out in the sun during the hottest time of the day. You don’t want to get heat exhaustion or another heat-related illness.

▪ Use EPA-registered mosquito repellents.The repellents should have DEET, picaridin, oil of lemon eucalyptus, or IR-3535.

▪ Clean out rain gutters.You don’t want the gutters clogged with branches and other debris that could make it easier for rain to pool. Check containers, pots, buckets, toys, plastic covers and other items in and around your home to make sure there’s no standing water too. Remember, standing water is a mosquito’s breeding ground.

▪ Change the waterin bird baths, fountains, wading pools and potted plant trays at least once a week, according to the EPA. And if you have a swimming pool, make sure to keep the water treated and circulating.

▪ Replace outdoor lights with yellow “bug lights.” These lights are not repellents, but they tend to attract fewer mosquitoes, according to the EPA.