New York City Health Department officials have traced a rare skin infection to Chinatown seafood markets. At least 30 people have reported skin lesions, appearing after handling raw or live fish, which officials warn is precisely how the bacteria, Mycobacterium marinum, infects a host — through a cut or other wound.

There is no risk from eating the food from the markets, according to a Health Department press release, but officials advise consumers use waterproof gloves when preparing a meal. The people infected reportedly bought fish from the Chinatown markets in Brooklyn, Queens, or Manhattan.

Dr. Jay Varma, the deputy commissioner for disease control at the Department, says the bacteria rarely causes infection in humans. “If you were to ask 100 doctors if they had seen a case, you would be lucky to find one who had,” he told The New York Times. “For us to see 30 cases clustered like this is very unusual.”

Antibiotics can treat the infection, but those suffering should not wait, as untreated infection may call for surgery to repair damaged nerves, tendons, or muscles. The infection begins with inflamed red lumps and swelling under the skin before it spreads to the tendons and muscles. People will thereafter experience pain and difficulty moving their fingers.

Health officials continue to investigate, paying particular attention to sanitation practices in seafood tanks.

Video courtesy of CBS New York: