This year, the Centers for Disease Control and Prevention reported nearly 3,000 dengue fever cases in the US, a significant increase compared to previous years. These record numbers of dengue fever highlight a growing concern for both local and international outbreaks, specifically in Paris, which is set to experience an influx of millions for the 2024 Olympics, posing a serious risk of this event becoming a dengue fever super-spreader.
As of June 30, the CDC has issued a Level 1 Travel Notice, but current and future travelers, and even those staying local for the foreseeable future, must understand how to protect themselves effectively against dengue fever.
What is dengue fever?
Also known as breakbone fever, dengue fever is a viral illness primarily spread by the Aedes aegypti mosquito, commonly known as the yellow fever mosquito. It’s generally a short-lived infection, often lasting no more than two weeks, depending on the individual and the severity of their symptoms.
“Symptoms of dengue typically last two to seven days,” Dr. Gabriela Paz-Bailey, chief of the CDC’s Dengue Branch, told CNET.
Different forms of dengue include dengue fever — of which there are four strains — and dengue hemorrhagic fever, which presents severe symptoms beyond those typically associated with a dengue infection.
What causes dengue fever?
“[Dengue fever is] caused by one of the four different but related viruses: dengue 1, dengue 2, dengue 3, dengue 4,” Paz-Bailey explained.
With four dengue virus strains, this means you can get dengue multiple times. While you may develop immunity to the first strain, you aren’t protected from the others, and repeated infections increase the risk of developing a severe illness.
Dengue fever risk factors
The World Health Organization reported that between 100 and 400 million dengue infections are recorded each year. Since early 2023, more than 7,300 deaths have been reported globally.
Individuals at risk of contracting dengue fever include:
- Residents of tropical and subtropical regions: People living in these areas are at higher risk because they are frequently exposed to Aedes mosquitoes, since warm, humid climates provide ideal conditions for mosquito breeding.
- Travelers to endemic areas: Individuals visiting regions where dengue is common are at risk if they encounter infected mosquitoes.
Dengue is more common in certain US territories, such as Puerto Rico and the Virgin Islands, but it has been seen in increasing numbers within the states.
“Locally acquired dengue cases have been detected in Florida, Texas, Hawaii, Arizona and California,” Paz-Bailey said. “Large outbreaks of dengue can increase the risk of dengue cases in US travelers. Because of the increased number of travel-associated cases and because the types of mosquitoes that spread dengue are present in some areas of the United States, small outbreaks might occur.”