Two patients in the outbreak were diagnosed in December and one in February.
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.
Leptospirosis is a bacterial infection most commonly spread by rat urine.
According to people living in the building, the rats have been an issue for years, and nothing has been done.
"They run from underneath your stove, your refrigerator", she said. "There's just holes where they find their way in". While it is very rarely spread from person-to-person, the illness can be serious.
Representatives from the city's health department were stationed in the lobby of 750 Grand Concourse Tuesday night, where they handed out notices to tenants warning them of the cluster of cases.
The city typically sees between one and three cases of leptospirosis per year, and the bacteria get into the body through cuts in the skin or the nose, eyes or mouth. She added, "There's a lack of concern about the building, there's a lack of concern with the super and the landlord". Leptospirosis is a disease caused by the bacteria Leptospira interrogans, which is found in nature. Some people who are infected may have no symptoms, while others may have mild illness with fever, headache, chills, muscle aches, vomiting or diarrhea. For example, people should wear shoes when they take their garbage to a trash compactor room, and avoid contact with areas in which rats might have urinated, according to The New York Times.
Wash hands thoroughly with soap and water after any contact with areas where rats may live. In rare cases, the disease causes severe complications in the kidney or liver that can result in organ failure and death.
The Health Department, in partnership with its sister agencies the Housing Preservation and Development (HPD) and Buildings Departments (DOB), is working with building owners in the affected area to remediate rodent infestations.