50 Years Since First Legionnaires' Outbreak, Still No Meaningful Progress on Disease Prevention

APLD urges more comprehensive approach to Legionella prevention in wake of latest deadly New York City outbreak

WASHINGTON, Aug. 11, 2026 /PRNewswire/ -- It was another hot and patriotic summer 50 years ago when a mysterious outbreak of severe pneumonia struck attendees of the 1976 American Legion convention in Philadelphia. A half century later, as communities across the country continue to experience preventable cases and outbreaks, the Alliance to Prevent Legionnaires' Disease (APLD) is calling on policymakers, public health officials, and water systems and building operators to adopt a comprehensive source-to-tap prevention strategy that addresses Legionella risks before people become sick.

According to the CDC, about 1 out of every 10 people who get sick with Legionnaires' disease will die due to complications from their illness, while approximately 10,000 cases of Legionnaires' disease are reported in the United States each year, the CDC cautions that the true burden is likely higher because the disease is underdiagnosed. In the 50 years since Legionnaires' was given its name, tens of thousands of Americans have lost their lives to this disease which is the leading cause of waterborne illness and death in the US. While outbreaks generate a lot of attention, according to the CDC, 96% of all cases are single or sporadic in nature - nearly 25 times more than occur as part of outbreaks. Sporadic cases seldom get visibility or comprehensive investigations.

APLD's call follows the recent Legionnaires' disease outbreak on Manhattan's Upper East Side where nearly 100 people became ill and seven deaths occurred. The outbreak underscored the persistence of this preventable illness and the limitations of a public health strategy centered primarily on responding to outbreaks after illnesses occur.

APLD advocates for a comprehensive "source-to-tap" approach that addresses Legionella risks throughout the entire water system, including source water, public treatment facilities through distribution systems, building plumbing and water-using equipment.

"Fifty years after the historic outbreak that first brought Legionnaires' disease to the nation's attention, we know far more about how it spreads but we must take a more integrated, holistic approach to this waterborne disease," said Dr. Hung Cheung, an APLD board member and medical advisor. "Preventing future cases and limiting illness and fatalities is possible through smarter public health strategies, but it requires a comprehensive approach that addresses Legionella risks before people become sick." Dr. Cheung is a current faculty member at the Perelman School of Medicine at the University of Pennsylvania and former Maryland State Medical Director.

Implementing this practice requires comprehensive monitoring and disinfection within public water systems, effective water quality management throughout distribution networks and strong water management practices inside buildings. It also requires greater coordination among public health agencies, water utilities, building owners, facility managers and other stakeholders responsible for protecting water quality.

To support this approach, APLD continues to work with policymakers, public health leaders and industry experts to advance science-based policies that strengthen Legionnaires' disease prevention through water management. In 2024, New Jersey enacted landmark legislation establishing a comprehensive source-to-tap approach to Legionella prevention. Similar legislation has since been introduced in New York, Pennsylvania and Maryland, where APLD has supported efforts to strengthen water management, improve case investigations, expand public education and reduce Legionella risks. Even when legislation is passed, implementation and enforcement of new regulations is critical to reducing risk.

"No family should have to experience a preventable loss," said Gwen Hanlon, APLD volunteer and victim's advocate whose husband, Kevin, died from the disease in 2017. "After 50 years, we know prevention is possible. Now we need to make it a priority before the next outbreak occurs."

About the Alliance to Prevent Legionnaires' DiseaseFounded in 2016, the Alliance to Prevent Legionnaires' Disease is a Washington, D.C.-based nonprofit coalition dedicated to reducing the occurrence of Legionnaires' disease through education, collaboration, public policy and science-based prevention strategies. APLD brings together experts in public health, engineering, medicine, water treatment, environmental health and industry to advance practical solutions that help prevent Legionnaires' disease before outbreaks occur.

To learn more, visit Preventlegionnaires.org.

SOURCE Prevent Legionnaires'