Spike in international travel leads to rise in harmful mosquito-borne illness in Florida

This year’s spike in international travel has brought more than 210 cases of mosquito-borne illnesses to Florida, including dengue, malaria, chikungunya, and West Nile Virus.

When it comes to dengue fever, most of the reported cases in 2023 are Floridians with a travel history to Cuba. So far this year, 141 travelers to Cuba were confirmed with dengue shortly after their return to Florida.  In total, 204 cases of dengue have been reported in 2023 by Floridians with travel history to a dengue-endemic areas, including Brazil, Peru, Mexico, Bolivia and the Dominican Republic. Just in the week ending Aug .12 alone, 14 cases of dengue were reported in people who had traveled internationally, according to the Florida Department of Health.

Peru is suffering its worst-ever recorded outbreak of dengue. So far this year, nearly 150,000 Peruvians have come down with the disease, according to the Pan American Health Organization.

South Florida is the area of the state where most cases of dengue are clustered. Miami-Dade has the majority of the international travelers who returned with dengue fever in 2023 with 120 cases; Broward has had 14 cases and Palm Beach has had seven cases in 2023.

In a rarer scenario, Florida has 11 locally acquired dengue cases: Broward has two cases and Miami-Dade has nine.  That means the disease is flourishing on its own in the area. On Thursday, Florida’s health department issued a mosquito-borne illness alert in both Miami-Dade and Broward counties.

“Dengue is spread by the bite of an infected mosquito and is not normally present in Florida. However, infected travelers can bring the virus back to Florida mosquitoes,” the Florida Department of Health-Broward said in a health alert.

There are four types of dengue, and people can be infected with each type throughout their lifetime.

“As long we have good mosquito control, we should be able to control the spread of these diseases in Florida, but we have to stay vigilant,” said Aileen Marty, an expert in infectious disease with Florida International University.  “One of things people don’t realize is the impact of heat on mosquitoes and what they carry. When it’s hot, the life cycle of mosquitoes gets short, so there can be a whole new crop once a week. Each mosquito builds up high quantities of virus in less time.”

Health officials say you can protect yourself from dengue and other mosquito-borne diseases by using insect repellent. Products with concentrations of up to 30% DEET are generally recommended along with repellents that contain picaridin, oil of lemon eucalyptus, para-menthane-diol, or IR3535.

According to Florida health officials, dengue fever can be painful but is rarely fatal. Symptoms appear three to14 days after the bite of an infected mosquito and include sudden onset of fever, severe headache, eye pain, muscle and joint pain, and bleeding. Gastrointestinal symptoms like vomiting and diarrhea may also be present in some cases.

At Cleveland Clinic Florida in Weston, Dr. Aisha Subhani, chair of the emergency department, has had patients arrive this summer with dengue fever after traveling to Latin America. “They have traveled and come back with headaches, fever … not feeling well. We test them for antibodies,” she said.

“We had a whole family who tested positive for dengue,” she said. “They didn’t need to be hospitalized. It’s not contagious.”

In addition to dengue, international travel also is associated with 38 cases of malaria reported in Florida this year. The travelers had been to areas such as Ghana, Nicaragua, Nigeria and Honduras.

Earlier this summer, the state health department alerted Floridians that seven cases of locally acquired malaria also had been reported in Florida in Sarasota County.

Symptoms of malaria are  fever, body aches, headaches, nausea, vomiting and diarrhea.

The other two types of mosquito-borne diseases have been less common this year. In 2023, two cases of West Nile Virus illness acquired in Florida was reported in Escambia County in July and one case of chikungunya was reported in Lee County in a person who had traveled to Brazil.

Sun Sentinel reporter Cindy Goodman can be reached at cgoodman@sunsentinel.com.