Isolation of Legionella pneumophila (serogroup one) from shower-water in Ballarat.

Five non-fatal cases of Legionnaires' disease occurred during 1979 and 1980 among patients living in Ballarat. The distribution of the dates of onset was sporadic, and no patient could be considered to have been at risk from faulty air-conditioning equipment; however, two of these patients, both female, had been resident, on separate occasions, in the reception ward of a long-stay institution during the incubation period of their illnesses. A fourfold rise in antibodies to the Philadelphia strain of Legionella pneumophila (serogroup 1) was demonstrated in all five of these patients, and subsequent examination of water in the shower block of the reception ward yielded a strain of the same serotype of L. pneumophila.