What to Know About Dengue Fever As It Spreads in the U.S.

Key Takeaways

If you recently posted photos of your toes on a sandy beach and then swatted at amosquito, you may have come into contact with a mosquito-borne disease that many Americans have never heard of—dengue fever. Known colloquially as “break-bone” fever, this vector disease is common in tropical climates around the world, affecting nearly half of the global population.But outbreaks have been infrequent in the continental United States—until now.

So far in 2024, the Centers for Disease Control (CDC) has reported 2,869 cases of dengue, with the highest concentrations occurring in Puerto Rico, Florida, New York, and California.What is dengue fever and how is it spreading? Here’s what two infectious disease specialists want you to know.

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What Is Dengue Fever?

Dengue can spread if another uninfected mosquito bites someone with the virus and then bites another person. When an infected mosquito feeds on a human, it can transmit one of four types of dengue fever: dengue 1, 2, 3, or 4.

Unfortunately, there is no treatment for dengue fever other than supportive care like resting and getting plenty of fluids.While people don’t feel well from the fever and pain that can be pretty bad, “the vast majority of people” will get better “in a couple of weeks,” said Shankaran.

However, “a small percentage of people that have been infected before may develop a hemorrhagic component with a second infection,” said Shankaran, adding that those patients “can become critically ill” from dengue.

There are also risks for other groups.Jarod Fox, MD, an infectious disease specialist at Orlando Health, told Verywell that pregnant people who are infected can transmit the virus to a fetus, leading to low birth weight or death.Immunocompromised people may also have more intense symptoms and take longer to recover from dengue.

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How to Avoid Dengue Fever

There is a vaccine for dengue fever (QDenga) that is approved in some countries. However, the World Health Organization only recommends it for children ages 6 to 16 who live in areas where dengue fever is endemic.The European Medicines Agency has approved it for adults, adolescents, and children four years or older.Qdenga hasn’t yet been approved in the U.S.

Several vaccines are also in development that may one day be available more widely to helpcurb the spreadof the virus.

Shankaran noted thatAedesmosquitoes are most active in warm climates and bite at dusk and dawn. It’s also worth knowing that some research suggests the use of artificial lighting at night may allow mosquitos to be more active later into the night.

While individuals can protect themselves in situations that seem high risk for dengue fever, the virus is now moving outside of the expected areas—and according to Shankaran, global travel is to blame.

“Dengue fever cannot pass from human to human,” said Shankaran. “But as people start traveling, you can potentially come back with the virus in your blood, then that allows local mosquitos to bite you and transmit the virus to someone else when they bite next.”

Fox and Shankaran advise people living or visiting warm climates to check the surrounding property for features that would attract mosquitos. For example, standing water gives the insects the chance to lay eggs and breed, creating an army of vectors for the virus.

Here’s How to Make Yourself Less Prone to Mosquito Bites

Is Dengue Spreading in Your Area?

Generally speaking, if you live in a warm climate near a travel hub, you may be at risk for dengue. So far, Miami-Dade County in Florida has the highest number of cases in the continental U.S., with Suffolk County, New York, and Broward County, Florida, trailing.

There have been more cases in the U.S. this year, but Fox said this increase reflects the global spread of the virus.

“The worldwide incidence of dengue is double what it was all of last year,” said Fox. “The warmer temperatures for longer periods of the year in more places is allowing for more transmission. There are more areas now with warm temperatures allowing for the mosquitos to thrive in areas they may not have in the past.”

To check the latest numbers in your area, visit theCDC website.

What This Means for YouIf you’re traveling to a tropical climate, like the Caribbean, Africa, or Central or South America, take precautions. Mosquito repellent and long sleeves and pants are the most effective measures, especially if you can’t stay inside during dawn and dusk.

What This Means for You

If you’re traveling to a tropical climate, like the Caribbean, Africa, or Central or South America, take precautions. Mosquito repellent and long sleeves and pants are the most effective measures, especially if you can’t stay inside during dawn and dusk.

12 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.World Health Organization.Dengue and severe dengue.World Health Organization.Dengue global situation.Centers for Disease Control and Prevention.Dengue: current year data.European Centre for Disease Prevention and Control.Aedes aegypti—factsheet for experts.Chuansumrit A, Chaiyaratana W.Hemostatic derangement in dengue hemorrhagic fever.Thromb Res. 2014;133(1):10-16. doi:10.1016/j.thromres.2013.09.028Centers for Disease Control and Prevention.Symptoms of dengue and testing.Centers for Disease Control and Prevention.About dengue.Rathore SS, Oberoi S, Hilliard J, et al.Maternal and foetal-neonatal outcomes of dengue virus infection during pregnancy.Trop Med Int Health. 2022;27(7):619-629. doi:10.1111/tmi.13783Ng KH, Zhang SL, Tan HC, et al.Persistent dengue infection in an immunosuppressed patient reveals the roles of humoral and cellular immune responses in virus clearance.Cell Host Microbe. 2019;26(5):601-605.e3. doi:10.1016/j.chom.2019.10.005European Medicines Agency.Qdenga: dengue tetravalent vaccine (live, attenuated).Coetzee BWT, Gaston KJ, Koekemoer LL, Kruger T, Riddin MA, Smit IPJ.Artificial light as a modulator of mosquito-borne disease risk.Front Ecol Evol. 2022;9:768090. doi:10.3389/fevo.2021.768090Centers for Disease Control and Prevention.Data and statistics on dengue in the United States.

12 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.World Health Organization.Dengue and severe dengue.World Health Organization.Dengue global situation.Centers for Disease Control and Prevention.Dengue: current year data.European Centre for Disease Prevention and Control.Aedes aegypti—factsheet for experts.Chuansumrit A, Chaiyaratana W.Hemostatic derangement in dengue hemorrhagic fever.Thromb Res. 2014;133(1):10-16. doi:10.1016/j.thromres.2013.09.028Centers for Disease Control and Prevention.Symptoms of dengue and testing.Centers for Disease Control and Prevention.About dengue.Rathore SS, Oberoi S, Hilliard J, et al.Maternal and foetal-neonatal outcomes of dengue virus infection during pregnancy.Trop Med Int Health. 2022;27(7):619-629. doi:10.1111/tmi.13783Ng KH, Zhang SL, Tan HC, et al.Persistent dengue infection in an immunosuppressed patient reveals the roles of humoral and cellular immune responses in virus clearance.Cell Host Microbe. 2019;26(5):601-605.e3. doi:10.1016/j.chom.2019.10.005European Medicines Agency.Qdenga: dengue tetravalent vaccine (live, attenuated).Coetzee BWT, Gaston KJ, Koekemoer LL, Kruger T, Riddin MA, Smit IPJ.Artificial light as a modulator of mosquito-borne disease risk.Front Ecol Evol. 2022;9:768090. doi:10.3389/fevo.2021.768090Centers for Disease Control and Prevention.Data and statistics on dengue in the United States.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

World Health Organization.Dengue and severe dengue.World Health Organization.Dengue global situation.Centers for Disease Control and Prevention.Dengue: current year data.European Centre for Disease Prevention and Control.Aedes aegypti—factsheet for experts.Chuansumrit A, Chaiyaratana W.Hemostatic derangement in dengue hemorrhagic fever.Thromb Res. 2014;133(1):10-16. doi:10.1016/j.thromres.2013.09.028Centers for Disease Control and Prevention.Symptoms of dengue and testing.Centers for Disease Control and Prevention.About dengue.Rathore SS, Oberoi S, Hilliard J, et al.Maternal and foetal-neonatal outcomes of dengue virus infection during pregnancy.Trop Med Int Health. 2022;27(7):619-629. doi:10.1111/tmi.13783Ng KH, Zhang SL, Tan HC, et al.Persistent dengue infection in an immunosuppressed patient reveals the roles of humoral and cellular immune responses in virus clearance.Cell Host Microbe. 2019;26(5):601-605.e3. doi:10.1016/j.chom.2019.10.005European Medicines Agency.Qdenga: dengue tetravalent vaccine (live, attenuated).Coetzee BWT, Gaston KJ, Koekemoer LL, Kruger T, Riddin MA, Smit IPJ.Artificial light as a modulator of mosquito-borne disease risk.Front Ecol Evol. 2022;9:768090. doi:10.3389/fevo.2021.768090Centers for Disease Control and Prevention.Data and statistics on dengue in the United States.

World Health Organization.Dengue and severe dengue.

World Health Organization.Dengue global situation.

Centers for Disease Control and Prevention.Dengue: current year data.

European Centre for Disease Prevention and Control.Aedes aegypti—factsheet for experts.

Chuansumrit A, Chaiyaratana W.Hemostatic derangement in dengue hemorrhagic fever.Thromb Res. 2014;133(1):10-16. doi:10.1016/j.thromres.2013.09.028

Centers for Disease Control and Prevention.Symptoms of dengue and testing.

Centers for Disease Control and Prevention.About dengue.

Rathore SS, Oberoi S, Hilliard J, et al.Maternal and foetal-neonatal outcomes of dengue virus infection during pregnancy.Trop Med Int Health. 2022;27(7):619-629. doi:10.1111/tmi.13783

Ng KH, Zhang SL, Tan HC, et al.Persistent dengue infection in an immunosuppressed patient reveals the roles of humoral and cellular immune responses in virus clearance.Cell Host Microbe. 2019;26(5):601-605.e3. doi:10.1016/j.chom.2019.10.005

European Medicines Agency.Qdenga: dengue tetravalent vaccine (live, attenuated).

Coetzee BWT, Gaston KJ, Koekemoer LL, Kruger T, Riddin MA, Smit IPJ.Artificial light as a modulator of mosquito-borne disease risk.Front Ecol Evol. 2022;9:768090. doi:10.3389/fevo.2021.768090

Centers for Disease Control and Prevention.Data and statistics on dengue in the United States.

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