The first cases of locally acquired chikungunya fever in the United States were reported Thursday in Florida: one in Miami-Dade County and the other in Palm Beach County, the Florida Department of Health announced.
Chikungunya is a disease spread by bites from infected mosquitoes. If a person is infected and bitten by a mosquito, that mosquito could later spread the infection by biting another person. Chikungunya is not contagious from person to person, is typically not life-threatening and will likely resolve on its own, state officials said.
Though 81 cases of the virus had been reported in Florida even before Thursday, including a new case confirmed in Pinellas County on Tuesday, none of them was contracted in the U.S. The mosquito-borne disease is widespread in the Caribbean, and the latest case in Pinellas County was an 81-year-old woman who returned from the region after traveling there in June and early July.
Experts had expected the disease to make its way to the United States.
"The department has been conducting statewide monitoring for signs of any locally acquired cases of chikungunya." said Dr. Anna Likos, state epidemiologist. "We encourage everyone to take precautions against mosquitoes to prevent chikungunya and other mosquito-borne diseases by draining standing water, covering your skin with clothing and repellent, and covering doors and windows with screens."
The virus is spread mostly by two breeds of mosquito, Aedes aegypti and Aedes albopictus. They bite in the daytime and are also famous for transmitting the dengue virus. Both species live in Florida.
U.S. Centers for Disease Control said in a statement that it is working with Florida health officials to identify additional cases.
CDC officials think chikungunya will behave like dengue virus in the United States, where imported cases have resulted in sporadic local transmission but have not caused widespread outbreaks. None of the more than 200 imported chikungunya cases between 2006 and 2013 has triggered a local outbreak. However, more chikungunya-infected travelers coming into the United States increases the likelihood that local transmission will occur.
Symptoms include high fever and joint pain. In rare cases, particularly in the very old or very young, or those with weakened immune systems, the symptoms can be prolonged and joint pain can be severe. There have been a few deaths associated with the disease, but the victims had serious underlying health issues.
There is no treatment beyond ibuprofen and fluids, but in healthy sufferers, the symptoms are short-lived.