NYC and Ontario Address Clusters of Legionnaires’ Disease
Recent community clusters of Legionnaires’ disease in New York City and Ontario are drawing the public’s attention to the serious illness, which is caused by Legionella bacteria. The Legionnaires’ disease cluster in New York City is affecting Central Harlem, and the cases in Ontario, Canada, were in a community in the Middlesex-London region. As of Aug. 13, 92 cases of Legionnaires’ disease have been confirmed in New York City, three people have died from the illness, and 15 are currently hospitalized. In the Middlesex-London region of Ontario, 70 cases were confirmed, three people died, and one person remains hospitalized. A total of 64 hospitalizations resulted from the outbreak in Ontario, which local health officials declared over last week.
A notice from the NYC Health Department (PDF) informs residents in and around Central Harlem that the likely source of Legionella in the community is a cooling tower in the area. The health department is sampling and testing water from cooling towers in the area and requiring treatment for those with positive results for Legionella. According to the website of the Middlesex-London Health Unit, environmental sampling of potential sources of Legionella is ongoing, and the health unit is working with Public Health Ontario, an organization focused on infectious disease outbreaks and environmental incidents, to identify the source of that outbreak.
“At this time, a point source of the Legionella bacteria has not been identified,” the news update from the Middlesex-London Health Unit states. “Despite collecting 126 environmental samples from 26 cooling tower sites, all close to the geographic [center] of the cases, no samples have yet detected legionella bacteria that is a match for that identified in the cases.”
Reported cases of Legionnaires’ disease have generally been increasing since the early 2000s, according to CDC. The Public Health Agency of Canada states that the average number of cases reported in the country each year is generally less than 100 but notes that “the actual number of cases is thought to be much higher, as many people with pneumonia may not be tested for infection with Legionella.”
To learn more about these recent outbreaks, visit the websites of the NYC Health Department and the Middlesex-London Health Unit.
AIHA has several resources related to Legionella. A technical framework describes fundamental knowledge levels of professionals involved with Legionella assessment. Recordings of courses, webinars, and AIHA Connect sessions that focus on Legionella, Legionnaires’ disease, and building water systems are available from AIHA University. And interested individuals can preview the second edition of the AIHA publication Recognition, Evaluation, and Control of Legionella in Building Water Systems.
Readers may also be interested in “Legionella Regulations in New York,” an article that was published in the June/July 2019 Synergist.