So far, 66 people who handled seafood in Chinatown markets have been infected with a rare skin infection. View Full Caption DNAinfo/Ewa Kern-Jedrychowska

NEW YORK CITY — The number of people affected by a rare skin infection linked to the city’s Chinatown fish markets has more than doubled since the Health Department announced the outbreak last month.

So far, 66 people who bought and handled live or raw seafood from Chinatown markets in Lower Manhattan, Flushing and Sunset Park in the past seven months are either affected by or suspected of having the skin infection “M. marinum,” according to the Health Department.

“I noticed the first one in August of last year, then again in September and more in November,” said Dr. Danny Fong, the hand surgeon who first reported the outbreak to the Health Department. “In my experience I see a case every year or two."

This year, he has treated between 15 and 20 patients since last August, all of whom were reported to the Health Department.

According to the health department, there have been 7 confirmed cases of the disease and 59 people are suspected of having it.

Most reported symptoms in the fall, but a few became ill more recently, a DOH spokesman said.

So far there have been no deaths or reported amputations, health officials said.

The infection is easily treatable with antibiotics but if it spreads to the muscles and nerves it requires surgery. Several infections have lead to surgery, Dr. Fong said.

Symptoms include red, tender swelling under the skin, hand or arm pain, and difficulty moving fingers, officials said.

The Health Department is still investigating the source of the outbreak and is asking people handing live or raw fish to wear waterproof gloves.

It is safe to eat the contaminated seafood and the bacteria is not contagious between humans, officials said.

“There are no cases in the medical literature of this type of infection from eating raw fish,” said a DOH spokesman.

“For reasons that are not completely understood, the bacteria has a preference for infecting the extremities of the body, such as arms, hands, feet, or legs, and only causes an infection when a person comes in direct contact with fish seafood, or the water from a fish or seafood tank and they have a cut or injury on that extremity.”