CDC warns U.S. doctors to watch for dengue fever amid increased cases in Puerto Rico

The Centers for Disease Control and Prevention has issued a health advisory warning authorities and healthcare providers about the increased risk of dengue fever infections in the United States.

In their alert, the CDC said that many countries have reported “higher-than-usual” numbers for cases and that countries in the Americas have reported a record-breaking amount of cases in 2024.

In 2023, countries in North and South America reported about 4.6 million cases. Roughly halfway through 2024, the number of cases has more than doubled – to 9.7 million, according to the CDC.

Puerto Rico has been hit the hardest. The U.S. territory has reported 1,498 cases in 2024, and declared a public health emergency in March surrounding dengue fever.

“We’re currently seeing is increases in the cases due to dengue 2 and dengue 3, for which the population has very little immunity,” Dr. Gabriela Paz-Bailey, the Puerto Rico-based chief of the CDC’s dengue branch, told the Associated Press.

Despite the virus being less common in the United States, the CDC is advising U.S. doctors to look out for dengue symptoms amid increased numbers in both the country and surrounding areas. That said, the virus is deceptive, with only 1-in-4 cases being symptomatic for patients.

The most common symptom among people infected with dengue is fever. Other common ones include migraines, nausea, vomiting, rash and body pain.

NBC reports that the CDC plans to expand laboratory testing for the virus to diagnose cases more effectively, while also educating the public on the disease. Another recommendation is to use insect repellent since most cases begin with a mosquito bite.