Mosquito-borne dengue virus lands in Key West

They call it “break-bone fever” because of the agonizing muscle and joint pain it causes, while extremely severe cases can trigger internal hemorrhaging.

Although the mosquito-borne dengue virus was thought to be fully eradicated in the continental United States, the Centers for Disease Control and Prevention confirmed Wednesday that the tropical disease had indeed returned.

In a study published in the CDC journal Emerging Infectious Diseases, authors identified Key West, Fla., as ground zero for transmission of dengue in the U.S..

Dengue, which is commonly spread through the bite of a female Aedes aegypti mosquito, causes flu-like symptoms. Severe cases, particularly in infants, can be fatal.

The disease is the world’s most common mosquito-spread virus, according study lead author Jorge Munoz Jordan, chief of molecular diagnostics and research at the CDC’s dengue branch. While cases of dengue fever have occurred in the U.S. Virgin Islands, Puerto Rico and American Samoa, mainland U.S. residents have had to travel overseas to be exposed.


However, after reviewing 93 dengue cases diagnosed in Florida in 2009 and 2010, study authors identified a specific strain of the virus in patients who had not recently traveled outside the country. The strain differed from those cases in which the patient had recently traveled.

“Findings indicate endemic transmission of [dengue virus] into the continental United States,” the study’s authors wrote.

The use of genetic fingerprinting will prove critical in following its spread, the authors said.

Aedes aegypti mosquitoes have shown resistance to traditional pesticides, so the Florida Keys Mosquito Control District has proposed using genetically modified insects to battle the disease.

By releasing thousands of sterilized male mosquitoes into the wild, vector control officials hope that they can reduce the overall number of mosquito offspring. The plan has generated some controversy and is currently awaiting approval by the U.S Food and Drug Administration.

Key West health officials have voiced frustration over the CDC report. See story here.

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