Dengue Fever Cases Increasing in US as CDC Issues Warning

Symptoms depend on the severity of the disease. Around 75% of people with dengue fever will not experience symptoms.

Mild symptoms may include a sudden fever of around 104°F (40°C) and one or more of the following:

Symptoms usually last between 2–7 days, and most people feel better after one week. The fever typically persists for at least 24 hours and may spike again.

Between 0.5% and 5% of cases become severe and can be life threatening.

In this instance, the fever typically falls to 99.5 to 100.4°F (37.5 to 38°C). Anywhere between a day and a week later, additional symptoms include:

There are currently four known strains of the Dengue virus, and there is no cure, so essentially, anyone bitten by a mosquito carrying the virus could catch it.

Dr. David Cutler, MD, board certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, told Healthline that those at highest risk of severe dengue, which can result in death, are infants under 1, pregnant people, adults over 65, or those with underlying medical conditions like hypertension, diabetes, asthma, chronic kidney disease, chronic liver disease, peptic ulcer disease or other gastritis, obesity, or anyone receiving anticoagulation medications.

“Treating dengue requires supportive care as there is no cure for this disease. Monitoring fever, hydration status and blood tests are important for detecting any signs of the disease becoming critical. Controlling fever, preventing dehydration and restricting disease spread through mosquito control are the most important measures to managing dengue,” said Dr. Cutler.

“Preventing [the] spread of disease, especially in young children, requires that everyone sleep under a mosquito net. Insect repellents are also an important preventive measure. Emptying and cleaning standing water containers deprives mosquitoes of places to breed. Screens on windows and doors will help prevent mosquitoes from entering the home,” Dr. Cutler explained.

Dr. Jessica Tuan, MD, an infectious diseases specialist at Yale Medicine, told Healthline that traveling to areas where dengue is most prominent also puts people at risk for exposure.

“Those who have traveled to dengue-endemic areas are at highest risk for acquiring dengue. Dengue is endemic in tropical areas including Africa, the Americas, Southeast Asia, Eastern Mediterranean region, and the Western Pacific. Areas with frequent or continuous dengue transmission include Puerto Rico, U.S. Virgin Islands, American Samoa, Republic of Marshall Islands, Federated States of Micronesia, Republic of Palau,” Dr. Tuan said.

“Take measures to prevent mosquito bites, including using mosquito repellent, for those traveling to or living in dengue-endemic areas. The Advisory Committee on Immunization Practices recommends the dengue vaccine, Dengvaxia, for children 9–16 years old with prior laboratory-confirmed dengue virus infection and living in areas with frequent or continuous dengue transmission,” she added.

Dr. James Shepherd, MD, an infectious diseases specialist at Yale Medicine, told Healthline that the dengue virus cannot mutate the way the COVID-19 virus has simply because there’s no cure for it.

“As there is no treatment there is no selection for treatment resistance. Is that a possibility in the near future? Not without development of new treatments to select resistance. There may be selection by human and mosquito host factors and evolution of viral pathogens is a natural process but there are no significant changes in the virus correlating with human disease that I am aware of,” Dr. Shepherd said.

Dr. Shepherd added that as the CDC expects more cases of dengue due to rising global temperatures, finding some sort of antiviral medication might be possible.

“As Aedes mosquitoes spread northwards with rising global temperatures dengue outbreaks are becoming more common in more temperate, richer countries and this presents a greater incentive for drug companies to spend on new antiviral drug development,” Dr. Shepherd said.