In The Lancet Infectious Diseases, Patricia Priest and colleagues1 report the first near-nationwide study of routine systematic PCR testing to assess the incidence of Legionnaires' disease in hospitals in New Zealand. They found that the overall incidence was 5·4 per 100 000 population, and Legionella longbeachae, not detected by the urine antigen test, was the cause in 150 (63%) of 238 cases.