Dengue cases in Guatemala, Mexico, and Honduras, 2023-2024 and 5-year average. In the Region of the Americas, the number of dengue cases recorded during the first half of 2024 exceeded the maximum number of cases historically reported in a year, as compared to all previously recorded years. As of epidemiological week (EW) 23 of 2024, 43 countries and territories in the Region of the Americas have reported 9,386,082 cases of dengue; this number is twice as high as the number of cases recorded throughout 2023, 4,617,108 cases. Data: Adapted from the Pan American Health Organization / PLISA Health Information Platform for the Americas, Dengue Indicators Portal, Washington, D.C. PAHO; 2024 cited 13 June 2024. Graphic: PAHO / WHO
Dengue cases in Guatemala, Mexico, and Honduras, 2023-2024 and 5-year average. Graphic: PAHO / WHO

By Finn Cohen
27 June 2024

(Healthline) – As cases of dengue fever rise worldwide, the Centers for Disease Control and Prevention (CDC) issued an advisory for physicians, public health authorities, and the public in the United States to be alert to the trend.

So far in 2024, cases of dengue fever in countries in the Americas have reached record-breaking levels, with more than 9.7 million reported cases — twice the number for the entire year in 2023 (4.6 million). Puerto Rico declared a public health emergency in March after the World Health Organization declared one in December 2023.

In the mainland U.S., 745 cases have been identified in travelers in the first six months of the year, which is higher than normal. There are no vaccines for anyone who has not previously had a dengue infection, and there is one vaccine for children between the ages of 9 and 16 who have been infected, but the manufacturer has discontinued production due to a lack of demand. In Puerto Rico, for example, available doses are expected to expire in 2026.

There are four strains of dengue, all carried by the Aedes mosquito, which generally lives in tropical and subtropical regions. The hotter and wetter months of the year are typically when cases of dengue peak, but as global temperatures rise, the CDC says, cases will most likely increase each year. […]

Dengue cases in the Americas, 1980-2024. In the Region of the Americas, the number of dengue cases recorded during the first half of 2024 exceeded the maximum number of cases historically reported in a year, as compared to all previously recorded years. As of epidemiological week (EW) 23 of 2024, 43 countries and territories in the Region of the Americas have reported 9,386,082 cases of dengue; this number is twice as high as the number of cases recorded throughout 2023, 4,617,108 cases. Data: Adapted from the Pan American Health Organization / PLISA Health Information Platform for the Americas, Dengue Indicators Portal, Washington, D.C. PAHO; 2024 cited 13 June 2024. Graphic: PAHO / WHO
Dengue cases in the Americas, 1980-2024. In the Region of the Americas, the number of dengue cases recorded during the first half of 2024 exceeded the maximum number of cases historically reported in a year, as compared to all previously recorded years. As of epidemiological week (EW) 23 of 2024, 43 countries and territories in the Region of the Americas have reported 9,386,082 cases of dengue; this number is twice as high as the number of cases recorded throughout 2023, 4,617,108 cases. Data: Adapted from the Pan American Health Organization / PLISA Health Information Platform for the Americas, Dengue Indicators Portal, Washington, D.C. PAHO; 2024 cited 13 June 2024. Graphic: PAHO / WHO

Who is at risk for dengue fever?

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.

Dengue cases in Colombia, Ecuador, and Peru, 2023-2024 and 5-year average. In the Region of the Americas, the number of dengue cases recorded during the first half of 2024 exceeded the maximum number of cases historically reported in a year, as compared to all previously recorded years. As of epidemiological week (EW) 23 of 2024, 43 countries and territories in the Region of the Americas have reported 9,386,082 cases of dengue; this number is twice as high as the number of cases recorded throughout 2023, 4,617,108 cases. Data: Adapted from the Pan American Health Organization / PLISA Health Information Platform for the Americas, Dengue Indicators Portal, Washington, D.C. PAHO; 2024 cited 13 June 2024. Graphic: PAHO / WHO
Dengue cases in Colombia, Ecuador, and Peru, 2023-2024 and 5-year average. Graphic: PAHO / WHO

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. [more]

Dengue Fever: CDC Issues Alert Amid US and Global Spike in Cases