Serological studies of legionellosis in New Zealand

The service performed by the Legionella Reference Laboratory in New Zealand over the last 4 years is described. During this period the number of antigens used in the indirect fluorescent antibody test increased from 4 to 19. The percentage of patients diagnosed has risen concomitantly. Species or serogroups found particularly frequently included L. pneumophila serogroup (SG) 6, L. micdadei, L. jordanis and L. longbeachae SG 1. Cultural studies and direct fluorescent antibody (DFA) studies were also performed. In addition to other species or serogroups, L. dumoffii was isolated from a patient and L. oakridgensis was observed by DFA in a postmortem specimen.