I’ve written a few articles about dengue fever, which may make it appear that I’m obsessed with the disease. However, I follow dengue fever because it is a tropical disease, like malaria and other mosquito vector diseases, that is moving north into Florida and California, as a result of human-caused climate change.
This article will review what is dengue fever, how to prevent it, and what is going on in Florida.
What is dengue fever?
Dengue fever is one of four viruses transmitted by the Aedes aegypti mosquitoes to humans. It infects over 100 million people a year worldwide. A. aegypti is endemic throughout Florida.
The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.
Dengue hemorrhagic fever (DHF) is a more severe form of dengue infection. It can be fatal if unrecognized and not properly treated in a timely manner. DHF is caused by infection with the same viruses that cause dengue fever. With good medical management, mortality due to DHF is still significant but can be reduced to less than 1%.
Dengue fever is not transmitted from one person to another with direct contact, only from the bite of the A. aegypti mosquito.
Although dengue fever is relatively rare in the USA, there have been outbreaks in 2009 and 2010 in the Florida Keys along with one in 2005 in Texas. Dengue fever is endemic in Mexico, so carrier mosquitos could hypothetically cross the border into Southern California without much trouble, especially if the weather is wet (like it has been in 2023).
There are several outbreaks of dengue fever observed across the world in 2023. And with higher temperatures and sea level rises, the mosquito vectors for Dengue will move further and further north putting more of the world population at risk.
Florida has been trying to eradicate the dengue-carrying mosquitos by using genetically modified mosquitos to breed with the native population of mosquitos. The initial testing phases have gone well.
There is a vaccine to prevent dengue. It is approved for children ages 9 – 16 who have previously had dengue and live in areas where dengue is common. Clearly, your local Los Angeles-based pediatrician is not going to have the vaccine available. And it probably won’t become widely available in Southern California unless there are many more cases of dengue.
Dengvaxia is the USFDA-approved vaccine for dengue fever and is indicated for preventing dengue virus serotypes 1, 2, 3, and 4. The Dengvaxia® vaccine is available for certain people following a pre-delivery diagnostic test review.
One of the best ways to prevent dengue is by avoiding mosquito bites:
- Wear insect repellent with DEET or another U.S. Environmental Protection Agency (EPA)-registered insect repellent. Make sure to follow the instructions for using the repellant.
- Wear clothes that cover your arms, legs, and feet.
- Close unscreened doors and windows.
Dengue fever in Florida
Florida has reported over 500 cases of dengue fever during 2023. Most of the cases are from individuals who have traveled outside of Florida to areas where dengue fever is endemic, mostly Cuba.
However, 20 new cases of locally acquired dengue were reported in South Florida, increasing this year’s total to 98. That means these individuals acquired dengue fever probably from local mosquitos rather than from traveling to an endemic area. Of those 98 locally acquired cases, 91 of them were in the Miami-Dade area of the state.
As I mentioned in the previous section, Florida is attempting to eradicate the A. aegypti mosquito to reduce the chances of dengue fever spreading more widely. Because of Florida’s near tropical location, disease-carrying mosquitos may become much more problematic as the climate warms. However, the Florida Health Department and the various mosquito abatement districts are doing their best to reduce the risk to residents of the state.
Although the CDC isn’t recommending the dengue fever vaccine for residents of Florida, it’s good to know that it is available as cases of the disease grow over the next few years. Plus, residents should do everything they can to reduce the risk of mosquito bites.
Citations
- Centers for Disease Control and Prevention (CDC). Dengue hemorrhagic fever–U.S.-Mexico border, 2005. MMWR Morb Mortal Wkly Rep. 2007 Aug 10;56(31):785-9. Erratum in: MMWR Morb Mortal Wkly Rep. 2007 Aug 17;56(32):822. PMID: 17687243.
- Graham AS, Pruszynski CA, Hribar LJ, DeMay DJ, Tambasco AN, Hartley AE, Fussell EM, Michael SF, Isern S. Mosquito-associated dengue virus, Key West, Florida, USA, 2010. Emerg Infect Dis. 2011 Nov;17(11):2074-5. doi: 10.3201/eid1711.110419. PMID: 22099104; PMCID: PMC3310564.
- Radke EG, Gregory CJ, Kintziger KW, Sauber-Schatz EK, Hunsperger EA, Gallagher GR, Barber JM, Biggerstaff BJ, Stanek DR, Tomashek KM, Blackmore CG. Dengue outbreak in Key West, Florida, USA, 2009. Emerg Infect Dis. 2012 Jan;18(1):135-7. doi: 10.3201/eid1801.110130. PMID: 22257471; PMCID: PMC3310087.
