By Joe Sutton and Catherine E. Shoichet
Florida health officials say they've confirmed eight cases of dengue fever.
Those infected have no history of recent international travel, the Florida Department of Health said Tuesday, "so exposure was likely from local mosquitoes."
The cases were reported in two southeastern Florida counties: Martin and Miami-Dade.
Dengue acquired from local mosquitoes is rare in the United States, Florida health officials said, urging residents to take steps such as wearing repellent to protect against mosquito-borne illnesses.
Dengue fever is passed from person to person by mosquitoes. Unlike malaria, there are no drugs to prevent it. It also is difficult to treat and thus far, attempts to develop a vaccine have been unsuccessful.
The World Health Organization estimates that there are between 50 million and 100 million infections each year.
Dengue is most common in Asia and India, but more cases have been popping up in the Caribbean and Latin America in recent years.
In mild cases, dengue fever causes a high fever, rash and joint and muscle pain. In extreme cases, it can cause death. According to the World Health Organization, about 12,000 people die of dengue fever each year.
The U.S. Centers for Disease Control and Prevention say dengue rarely occurs in the United States.
But this isn't the first time Florida has dealt with dengue.
In 2009 and 2010, officials documented 28 locally acquired cases in Key West.
CNN's Miriam Falco and Jennifer Bixler contributed to this report.
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