Cases of a mosquito-borne disease once largely confined to tropical regions are spiking.

According to a recent report from the CDC, a record number of cases of dengue were reported in the US in 2024, resulting in a 359% increase in incidence of the fearsome fever.

Symptoms include fever, nausea, vomiting, rash, and joint or bone pain — the latter of which can be so acute that it’s earned the disease the dubious nickname “breakbone fever,” as victims compare the agony to having their bones broken.

According to the CDC, 3,798 cases of dengue were reported in 2024, compared to the annual average of 828 from 2010 to 2023.

Of these cases, over a third of patients were hospitalized, and six died. Though symptoms can be severe, it’s usually not fatal in otherwise healthy patients.

While the majority of 2024’s cases were travel-related (97.2%), the remaining 2.8% were locally acquired, suggesting that the risk of local transmission is steadily increasing.

“Dengue is a public health threat to persons of all ages,” the agency maintains.

Dengue is transmitted to humans through the bite of infected Aedes mosquitoes, the same damnable species that spreads Zika, yellow fever and several other viruses.

Aedes mosquitoes have historically been found in tropical locales, but over the past several decades, due to climate change, their dangerous range has expanded.

Since 2000, there’s been a global surge in dengue cases, peaking in 2024 at over 14 million, a number the WHO describes as a “historic high.”

The majority of these cases were reported in the Caribbean (34.1%), North America (24.3%) and Central America (15.6%). 

In 2024, over 100 locally acquired cases were reported in the US. In Florida, California and Texas, infections were documented in several counties, suggesting the virus was introduced multiple times rather than as part of a single outbreak.

There was also a 2024 outbreak in New Jersey, sickening dozens of people.

“Although these introductions did not lead to larger outbreaks in the continental United States, they indicate an increasing risk for locally acquired cases, underscoring the need for enhanced surveillance, vector control, and public health preparedness and response efforts in areas with competent mosquito vectors,” the CDC said.

Experts note the real potential for dengue to tighten its grip in the US, as the Aedes mosquito is found in roughly half of the country’s counties, with 75% of those counties having climates that allow the insect to flourish.

According to the CDC, about 1 in 20 people infected with dengue contract a more severe form of the infection that can lead to life-threatening complications, including hemorrhaging, blood in vomit or stool, dangerously low blood pressure, internal bleeding, shock, organ failure and even death.

There are four distinct dengue strains, and surviving one infection confers immunity only to that strain. Subsequent infection with another strain of the virus amplifies the risk of developing severe dengue symptoms.

Infants under 1 year old, senior citizens or people with certain medical conditions are considered at higher risk of contracting severe disease.

There are no known medications to treat the virus, and the CDC says the best way to prevent infection is to avoid mosquito bites whenever possible and to take steps to control their population growth, such as emptying outdoor containers of standing water where the insect’s eggs thrive.