Legionnaires’ Outbreak in Central Harlem: What You Need to Know

Updated August 14, 2025 — New York City is contending with a serious Legionnaires’ disease outbreak centered in Central Harlem. Since late July, health officials have confirmed nearly 100 cases and four deaths, marking a tragic escalation from earlier reports of two fatalities. New York Post.

The outbreak has been traced to 12 contaminated cooling towers—including those at Harlem Hospital, CUNY’s Marshak Science Building, the Central Harlem Sexual Health Clinic, and buildings managed by the NYC Economic Development Corporation New York Post. Eleven of these towers have already been disinfected, with the final one scheduled for cleanup. New York Post.

Officials are urging caution among residents and workers in ZIP codes 10027, 10030, 10035, 10037, and 10039, as the bacteria can spread through airborne droplets beyond immediate surroundings New York Post. Because Legionnaires’ can take up to two weeks to manifest symptoms, the city remains vigilant even as new cases begin to decrease. New York Post

Legionnaires’ disease is a serious form of pneumonia caused by Legionella bacteria prevalent in warm water systems like cooling towers, hot tubs, and large HVAC systems AP News. It is not contagious between people; the only route of infection is through inhaling contaminated water vapor New York Post

Common symptoms include fever, cough, shortness of breath, muscle aches, headaches, and occasionally gastrointestinal distress. Vulnerable groups—such as those aged 50+, smokers, or individuals with respiratory or immune conditions—are at heightened risk AP News. Early antibiotic intervention is essential and can substantially improve outcomes CT Insider.