The New York City health department says one person has died and two others have become severely ill after they contracted a rare infection called leptospirosis, which is transmitted by rats.
The three cases occurred in the last two months in a Bronx neighborhood. City officials say it's the first time a cluster of cases has been identified.
Infections commonly occur through exposure to rat urine. The disease is rarely spread from person to person. It can be treated with antibiotics.
The city says it's reducing the rat population in the area and educating residents about the disease.
The New York Times reported that from 2006 to 2016, 26 cases were reported in the city; the Bronx had the highest number with eight.