Health Check Special Report: Chikungunya

Aedes aegypti mosquito

Al Gettman has made a career out of trapping mosquitoes with Rhode Island's Department of Environmental Management.

On any given Monday afternoon during mosquito season, he sets as many as 35 traps throughout the state. Every Tuesday morning, he collects those traps.

They're nothing fancy but they do the job.

"Here in this cooler is a chunk of dry ice that sublimes into gaseous carbon dioxide overnight and that's fed into the trap, and carbon dioxide is a very powerful mosquito attractant," Gettman said.

His job is to get a good sampling of mosquitoes from throughout Rhode Island in search of any infected with two potentially deadly mosquito-borne viruses: eastern equine encephalitis and West Nile virus.

Once collected, the mosquitoes are placed in a cooler along with dry ice.

"So that CO2 in there is going to kill the mosquitoes and keep them cool so the virus won't tend to denature," Gettman said.

But now, he's also on the lookout for the mosquito known as the Asian tiger. It's the type of mosquito that, among other diseases, can transmit the chikungunya virus.

"We've been looking for the Asian tiger mosquito for some years," Gettman said.

And the state has trapped a few, but not recently.

"The Asian tiger mosquito has been picked up here in Rhode Island just on three occasions about four or five years ago. We only picked up a handful of individual females, so that species is definitely not established here in Rhode Island," Gettman said. "It could become established someday."

To date, the more than 100 cases of chikungunya in the United States have been associated with travel, mostly to the Caribbean, where the infection rate is in the tens of thousands.

This virus is not typically deadly, but the symptoms of chikungunya are brutal.

"The word is derived from an African term that has something to do with bent over with pain," said Dr. Leonard Mermel, an infectious diseases expert at Rhode Island Hospital.

Mermel identified the first patient in Rhode Island with this virus. He was going over the records of a patient who presented with high fever, a rash and severe joint pain.

"Then I dug in the nurses notes and noted she had been in the Caribbean and they'd been in the Dominican Republic. I said, 'Wow, that sounds like the real deal,'" Mermel said. "The red flag was my flag as an infectious diseases doctor is the flag of joint pain."

Chikungunya is a nasty virus that can lead to long-term complications.

"You can have pretty severe joint pains, and one of the problems with people older in age can have arthritis, joint pain, muscles pains that go on for months to years. That's a problem," Mermel said.

The virus can be traced to Western Africa.

"Traveled to Madagascar, spread to Asia, eventually to western Europe," Mermel said, "and then to the Caribbean. It's now spreading quickly across many countries in the Caribbean."

And while it is not indigenous in the U.S.

"I think there's a reasonable chance it will become endemic in places like Florida," Mermel said.

Unlike most mosquitoes, the one that carries chikungunya -- the Asian tiger mosquito -- is noted for biting in the daytime, Gettman said.

But in order for it to spread in this country: "You need enough patients to have this in their blood, and you need enough mosquitoes that can be vectors for this," Mermel said.

Mermel said that's possible down the road, but not probable in the near future.

Mermel said he hopes all health care providers become familiar with the symptoms of chikungunya. All cases in the U.S. so far have been travel-related, especially since this virus can lead to long-term arthritic symptoms. Knowing what is causing these symptoms can eliminate unnecessary tests and treatments.

The Centers for Disease Control has exhaustive information on chikungunya. The Rhode Island Department of Health has information about protecting yourself from mosquito bites.