Fourth person dies in New York LD outbreak
15th August 2025
USA: A fourth person is reported to have died from the outbreak of legionnaires’ disease in New York City’s Harlem neighbourhood.
There have now been 99 confirmed cases confirmed since July 25 when the cluster was first identified. 17 people remain in hospital.
The New York City Health Department has confirmed that 12 cooling towers on 10 buildings have tested culture positive for live legionella bacteria. Eleven of the 12 cooling towers have completed remediation. The final cooling tower remediation is required to be completed today (August 15).
Acting health commissioner Dr Michelle Morse commented: “The good news is that new cases have begun to decline, which indicates that the sources of the bacteria have been contained.”
In a letter sent on Monday to Dr Morse, ASHRAE president Bill McQuade referenced ASHRAE Guideline 12-2023, Managing the Risk of Legionellosis Associated with Building Water Systems, a supplement to the ASHRAE legionellosis risk management standard 188-2021.
While recognising that several sections of Standard 188 were already referenced in the city’s existing requirements for certain buildings’ water management plans, McQuade advised that the entire standard be referenced in full, to ensure its effectiveness in mitigating legionnaires’ disease risk.
“We also recommend referencing the most recent edition of the standard (currently the 2021 edition), as each subsequent edition of the standard includes essential updates from the previous editions,” McQuade wrote.
ASHRAE Guideline 12-2023 provides detailed guidance for water management programme teams to develop the necessary elements of an effective water management plan.
“This outbreak underscores the importance of consistent, comprehensive water management practices in source water distribution systems and facilities of all sizes and types, and ASHRAE’s guidance offers design teams, building managers and health officials a structured approach to mitigating risk and protecting occupants,” McQuade added.
