What Is Dengue Fever and Is It Present in the U.S.?

Health officials issued an alert June 25 to warn health care providers and the public of an increased risk of dengue virus infections in the U.S. Globally, cases of the mosquito-borne

disease have been the highest on record this year, the advisory from the Centers for Disease Control and Prevention (CDC) said. And countries in the Americas have reported twice as many

dengue cases so far this calendar year — nearly 10 million — as in all of 2023, with many of the outbreaks occurring in Central and South America. In the U.S., a “higher than expected”

number of dengue cases have been reported. There have been a 2,241 in 2024, including 1,498 in Puerto Rico, which declared a public health emergency in March due to the concerning number of

cases that came during a time of year when counts are usually lower. Cases in the Americas have “skyrocketed this year,” Robert Murphy, M.D., an infectious disease expert and executive

director of the Robert J. Havey, MD Institute for Global Health at Northwestern University Feinberg School of Medicine, told AARP in December. And the CDC says cases will likely keep

climbing as global temperatures increase. The 10 warmest years on record have all occurred in the past decade, data from the National Oceanic and Atmospheric Administration shows. Higher

temperatures expand the range of the mosquitoes that transmit dengue. In addition to changing weather patterns, the swell in cases could also be due to more testing, says Michael Friedman,

M.D., a global public health expert and former CDC chief medical officer, epidemiologist and country director. “But regardless of that, this increase is a concern for sure,” he says. WHAT IS

DENGUE?   Dengue is a disease that’s caused by four related viruses commonly found in tropical regions that can be transmitted to humans by an infected mosquito from the Aedes species,

according to the National Foundation for Infectious Diseases. This type of mosquito also carries the Zika and chikungunya viruses. A dengue infection doesn’t always cause a person to get

sick, but those who do get sick typically experience symptoms that are similar to many other viral infections. The most common symptom is a fever (the illness is sometimes called dengue

fever) that can be paired with: * Aches and pains behind the eyes * Muscle, joint or bone pain * Nausea or vomiting * Rash For some people, the illness is mild and clears in about a week.

For others, a dengue infection can become severe — even life-threatening — and older adults are among the populations at higher risk for a serious case. A previous dengue infection can also

increase risk for a severe case.