THURSDAY, July 17, 2014 (HealthDay News) -- The first case of locally acquired chikungunya virus, which is transmitted by the bite of a mosquito, has been reported in the United States, federal health officials said Thursday.
The case involved an unidentified man from Florida.
Until now, all previously reported infections had originated outside the United States, officials said.
Chikungunya -- which triggers a very painful but seldom fatal illness -- is already common in central and southern Africa, southern Asia and has recently spread to 17 countries in the Caribbean, the CDC said last month. Cases have also been reported in Italy and France.
"The arrival of chikungunya virus, first in the tropical Americas and now in the United States, underscores the risks posed by this and other exotic pathogens," Roger Nasci, chief of the U.S. Centers for Disease Control and Prevention's Arboviral Diseases Branch, said Thursday in an agency news release.
The virus had been reported as close to the U.S. mainland as Puerto Rico and the U.S. Virgin Islands, Dr. Erin Staples, a medical epidemiologist at the U.S. Centers for Disease Control and Prevention's National Center for Emerging and Zoonotic Infectious Diseases, said last month.
Chikungunya virus is transmitted to people by two species of mosquitoes, Aedes aegypti and Aedes albopictus. Both species are found in the southeastern United States and limited parts of the southwest. Aedes albopictus is also found further north up the East Coast, through the Mid-Atlantic States and is also found in the lower Midwest, CDC officials said.
Chikungunya (pronounced chick-en-gun-ye) virus causes high fevers, joint pain and swelling, headaches and a rash. For some people, the pain can last even after other symptoms disappear, Staples said. Chikungunya can be fatal, though that's quite rare, she added.
The CDC said Thursday that it's unclear how chikungunya will spread, but agency experts believe it could follow the course of another mosquito-borne tropical threat, dengue fever. Dengue fever cases remain primarily of foreign origin in the United States, the CDC said, and "sporadic" cases of locally transmitted infections haven't led to widespread outbreaks.
Those most at risk of a severe infection from chikungunya virus include newborns, adults 65 and older, and people with chronic medical conditions, such as high blood pressure, diabetes and heart disease, according to Staples.
The mosquitoes that carry the chikungunya virus are active during the day, unlike those that carry West Nile virus, which are most active from evening to dawn. "These mosquitoes are predominately in the South and southeastern United States, and they have been found in pockets in the western United States," Staples said.
No treatment or cure exists for the chikungunya virus. Doctors can treat individual symptoms, but then can only wait for the illness to pass. The infection generally runs its course in about a week.
Like other mosquitoes, those that carry chikungunya breed in standing water, Staples said. So, it's a good idea to get rid of any sources of standing water around your home, she advised.
People should also use insect repellant when they go outdoors. And, wear pants and long sleeves outside whenever possible. Staples also recommended making sure window screens are in good condition to keep mosquitoes out of the house.
For more about the chikungunya virus, visit the U.S. Centers for Disease Control and Prevention.