CDC scientists detailed their findings in a report published this month. In 2024, nearly 4,000 cases of dengue were reported in the US, a record high and well above the normal annual average. Researchers say that although most of these cases were travel-related, the risk of local transmission is increasing over time.
“Dengue is a public health threat to people of all ages,” they wrote in their paper published in Morbidity and Mortality Weekly Report (MMWR).
‘Bone-breaking’ pain
Dengue is a mosquito-borne viral disease. Although most initial infections cause no symptoms, about a quarter of people will experience flu-like illness. For some people, the pain can be so excruciating that it has been compared to breaking a bone, earning it the nickname “break-bone fever”.
1% to 5% of people with dengue may experience serious, life-threatening complications such as internal bleeding and shock. There are four major serotypes of dengue virus, and surviving an infection provides immunity only to that specific type. The risk of severe dengue increases if re-infection with another type of virus occurs.
aedes Mosquitoes that spread dengue generally live in tropical areas. But in the last few decades, like dengue, their scope has also increased. Since 2000, there has been a large increase in dengue cases around the world, and the situation has recently become worse. According to the World Health Organization, more than 14 million cases were reported globally in 2024, a “historic high” and more than double the number in 2023 (which was a record in itself at the time). Most of these cases occurred in the United States.
According to the CDC report, there were a total of 3,798 cases of dengue in the US in 2024 – a 359% increase from the annual average between 2010 and 2023 (828 cases). Of these, 108 people developed severe dengue and six ultimately died.
future of dengue
The increase in cases in the US likely reflects the global surge. About 97% of these cases were travel-related, meaning the infection was initially caught somewhere else.
At the same time, more than 100 locally acquired cases were recorded in 2024. In three states, Florida, California and Texas, cases were found in multiple counties. This suggests that the virus came to these areas more than once, and not that the cases were part of a single larger outbreak. And since then, the possibility of dengue continuing to gain a foothold within the U.S. aedes Mosquitoes can be found in most parts of the country.
“Although these introductions did not cause large outbreaks in the continental United States, they indicate an increased risk for locally acquired cases, underscoring the need for increased surveillance, vector control, and public health preparedness and response efforts in areas with competent mosquito vectors,” the authors wrote. He said about half of U.S. counties are already home to mosquitoes that spread dengue, while three-quarters have the climate needed to make them comfortable.
Thankfully, 2025 was no less than a dengue nightmare, although there were still more than six million suspected and confirmed cases in the US. And the real toll is always significantly higher, given that many infected people do not experience the disease. So while 2024 may be a particularly bad year for dengue in the US and the world, it is likely to be a persistent and growing problem going forward, thanks in part to factors like climate change.
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