Dengue fever is popping up in unusual places this summer. Florida just issued an alert, and people in the know are concerned the Paris Olympics, set to take place later this month, could become a “super spreader event” for the disease. While cases are higher and more typical in places like Brazil, France has seen a record number of imported cases of dengue fever this year.
What gives? Climate change.
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How the climate crisis fuels diseases like dengue
Extreme heat, heavier rainstorms, and more dangerous hurricanes aren’t the only impacts of the climate crisis seen over the last year. One of the more nefarious ramifications of a changing planet are diseases that start earlier, spread wider, and reach regions that traditionally haven’t seen certain insect-borne viruses like Lyme disease from ticks or malaria, Zika, and now dengue, all spread by mosquitoes.
This winter and into spring, rising temperatures across Central and South America caused mosquitoes to hatch earlier and spread to cooler parts of the region, resulting in one of the worst outbreaks of dengue fever ever recorded.
In Brazil, 17 cities declared a state of emergency by early March, after the country registered one million cases of dengue by February, which is more than half of the cases confirmed in all of 2023. By the end of April, over 7.6 million dengue cases had been reported to the World Health Organization (WHO), with over 6 million of those suspected cases in Brazil, followed by Argentina, Paraguay, and Peru. As the disease continues to spread, the number of infected cases is rapidly breaking previous all time highs.
This does not appear to be an aberration. Sylvia Fischer, a doctor in biological sciences and researcher at the National Council for Scientific and Technical Research, told Reuters that the increasing number of mosquitoes was getting earlier each spring, which could lead to annual epidemics.
Dengue is a particularly devastating disease known as “break-bone fever”; the virus causes extreme muscle and joint pain, along with headache, skin rash, vomiting, and high fever. In severe cases, it can cause death. While only one in four people infected will develop symptoms, one in 20 who get sick could develop severe illnesses, according to the CDC. Despite this severity, there’s no antiviral medications. Treatment involves supportive care like over-the-counter ibuprofen and other anti-inflammatory drugs. Two vaccines are available, but they’re difficult for kids to get. For people never exposed to dengue, the vaccine could put them at higher risk for severe dengue should they get infected, according to the Washington Post.
Dengue in the U.S.
While dengue is particularly prevalent where mosquitos are common—in tropical and subtropical climates where about half the world’s population lives—research shows that potential for dengue transmission is now extending throughout the southeastern U.S. and could become a year-round phenomenon in southern Florida.
So far in the U.S., Puerto Rico has suffered the most. The territory declared a dengue epidemic in March. Puerto Rico had already documented the most cases of dengue among 30,000 cases split between four U.S. territories from 2010 to 2020. In 2012, 199 people died from dengue in Puerto Rico, but by March 10 of this year, almost 550 cases had already been recorded, and the numbers continue to rise.
While most people with dengue in areas not typically known for the disease, including Florida and France, caught it while traveling, of the 77 cases of dengue reported by Floridians by late March of this year, four were acquired in Florida, including three in Miami-Dade County and one in Pasco County, just north of Tampa. Last year, 172 cases were recorded in Florida, the leading state among other high-heat states where dengue is rising. Last year, Texas recorded more than 30 cases and California recorded at least two.
WHO reports there have been sporadic dengue cases and few dengue outbreaks reported in Europe since 2010 that appear not to be travel-related, including in Croatia, France, Italy, Portugal (Madeira), and Spain.
How to protect your children from dengue
Parents in states where dengue transmission is possible—especially in Florida now that an alert has been issued—can take the following precautions to protect themselves and their children:
- Use mosquito repellent containing nontoxic chemicals.
- Wear protective clothing in high mosquito areas, like long-sleeved shirts, long pants, socks, and shoes.
- Remove, repair, or empty any rainwater catchment systems, like used tires, flowerpots, and clogged gutters.
- Check and repair screen doors and windows.
- Eliminate indoor mosquitoes with nontoxic insecticides.
- Exercise caution in the early mornings and late afternoons, when mosquitoes are most active.
And if you’re lucky enough to be traveling to Paris this month, keep these tips in mind as you head out to watch Simone Biles, Katie Ledecky, and Nikki Hiltz compete for the gold.
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