A tropical infection with a tongue-twister name has been transmitted to a Florida man by a mosquito in that state, while three Long Island travelers contracted the same virus in the Caribbean and returned home debilitated in recent weeks.
Investigators from the Centers for Disease Control and Prevention confirmed chikungunya virus was transmitted to the Florida man, who had not traveled abroad.
Three cases of the infection -- all involving travel -- have been diagnosed at North Shore University Hospital in Manhasset, said Dr. David Hirschwerk, a specialist in infectious diseases and associate chairman of medicine.
Always mosquito-borne and never passed person to person, the chikungunya virus was first identified in the 1950s in what is now Tanzania. It causes fever and severe pain in the joints, which can be recurrent and last for years. Although not lethal, the illness is extremely debilitating. There are no approved vaccines or drug therapies, doctors say.
The infection is common throughout parts of sub-Saharan Africa, Southeast Asia, the Caribbean and South America.
A sweeping epidemic currently underway in the Caribbean took global health experts off guard as cases began mounting late last year.
About 355,000 people in more than 20 countries and jurisdictions throughout the Americas have been infected, and the CDC estimates 357 U.S. travelers have contracted chikungunya fever while visiting endemic areas.
'Florida case is unusual'Hirschwerk said he and his colleagues diagnosed chikungunya fever virus within the past six weeks. The Long Island patients were unrelated, he said.
"One of those cases has been confirmed by the CDC," Hirschwerk said, "and testing is still pending on the others.
"The likelihood of having more cases in individuals who have not traveled is very low," Hirschwerk said. "The Florida case is unusual and I don't expect to see high numbers [of infections] but we have to keep an eye on the situation."
For some experts, the emergence of chikungunya in Florida sounds an alarm because the virus is carried by mosquito species -- Aedes albopictus and Aedes aegypti-- that are well established in this country.
"The two species of Aedes mosquitoes that spread chikungunya are found in the southern and eastern United States," said Dr. Erin Staples, a medical epidemiologist at the CDC.
"It is difficult to predict how the disease will spread in the mainland U.S.," Staples said, "but we predict small, focal outbreaks, similar to pockets of dengue fever infections that have occurred previously in Florida and Texas."
At Stony Brook University, Dr. Jorge Benach said he was not surprised to learn of mosquito-transmitted chikungunya in Florida.
Infections after travels"I wouldn't be surprised if it happened here," Benach said.
There have been other instances of tropical mosquito-borne infections finding a niche in ecosystems outside their regions of origin, Benach said.
"The classic example is West Nile in 1999," added Benach, who is chair of molecular genetics and microbiology at Stony Brook's medical school.
"West Nile probably came into this country through Kennedy Airport and in 15 years it has spread across the country at a speed that has left some people marveling," he said.
Between 2006 and 2013 an average of 28 people in the United States tested positive each year for recent chikungunya infection, according to CDC data. All cases involved recent travel to affected areas, mostly Asia. This year, cases primarily involve travelers returning from the Caribbean.
Following another virusThe emergence of mosquito-transmitted chikungunya in Florida comes less than a year after dengue fever virus was transmitted by a mosquito to a Long Island man.
Suffolk County health officials confirmed last fall that a Babylon resident was hospitalized for dengue symptoms in September.
Although a dengue infection may produce no symptoms, it is capable of morphing into dangerous, life-threatening manifestations and so-called "breakbone fever" in a small percentage of people.
Suffolk health officials last year doubted the single case was a harbinger of an emerging regional infection. But they are certain that dengue was mosquito-transmitted because the man had not traveled beyond Long Island.
Experts theorized that a mosquito likely bit someone who had recently traveled to a dengue-endemic area, then bit the Babylon man.
No one is predicting a similar scenario for chikungunya.
Herschwerk said chikungunya is a concern, but West Nile is the most serious mosquito-transmitted infection here. "I wouldn't sound the alarm bells yet," he said about chikungunya.