Legionnaires' disease reports

​​​​​​​​​​​Summary​

Legionnaires' disease is an infection of the lungs (pneumonia) caused by Legionella bacteria. Infection occurs when a person breathes in bacteria that are commonly found in the environment.​ In NSW, most cases of Legionnaires' disease are caused by Legionella pneumophila or Legionella longbeachae.

Annual reports on Legionnaires' disease (Legionellosis) include analysis of notification data across the calendar year, including seasonal and yearly trends, the demographic and clinical characteristics of cases, and their risk factors. NSW Health undertakes surveillance and reporting on Legionnaires' disease to inform public health action to prevent illness. ​

Annual reports

​Legionellosis in NSW 2024​​


File Size: 1217 kb
Type: Report
Date of Publication: 02 February 2026
Author: One Health
ISBN: 978-1-74231-351-1
SHPN: (OH) 260050