Health officials in the Florida Keys issue a local dengue fever warning

A dengue fever warning has been issued in the Florida Keys after two cases of the mosquito-borne disease were confirmed.

The local warning came a week after the Centers for Disease Control and Prevention issued a national warning of an increased risk of dengue virus infections in the United States.

Although most of the dengue cases reported in the state so far this year have been travel-related, the two cases that triggered the alert in the Florida Keys were locally transmitted in Monroe County, according to Florida Department of Health officials.

A total of 2,241 dengue cases have been reported in the United States so far this year, including 1,498 cases in the U.S. territory of Puerto Rico, where a public health emergency was declared in March after the number of cases exceeded historical levels.

The CDC reported 3,036 cases of dengue in the United States and its territories last year.

The number of dengue fever cases worldwide is at an all-time high, especially in Latin American countries, where more than 9.7 million dengue cases have been reported so far this year. That’s twice the number reported for all of 2023 (4.6 million cases), according to the CDC.

The number of dengue infections is increasing as warmer temperatures are reported in many countries. These create ideal conditions for dengue-transmitting mosquitoes to hatch en masse and transmit larger quantities of the virus.

According to the CDC, about one in four people who become infected with the dengue virus become ill. Those who become ill may experience mild or severe symptoms.

The most common symptom in people infected with the mosquito-borne disease is fever, but other symptoms may include joint, muscle, bone or eye pain, headache, nausea, vomiting or rash.

Most dengue patients recover within a week, but about one in 20 cases develop severe dengue disease, which can be life-threatening and requires hospitalization as it can lead to shock, internal bleeding and even death.

People who have had dengue fever in the past are more likely to develop severe symptoms. According to the CDC, a person can get dengue fever up to four times in their lifetime—once for each type of virus that can cause the disease.

Prevention methods include staying in air-conditioned areas whenever possible or installing screens to keep mosquitoes out of the house, using insect repellent or wearing long sleeves and pants outdoors to avoid mosquito bites, and cleaning any areas with standing water where mosquitoes may breed, such as buckets, gutters, and other containers.