A prevalence study of antibodies toLegionellaspp. in geriatric institutions

Abstract

SUMMARYThe prevalence of scropositivity toLegionellaspp. was studied in inmates and staff members of two geriatric hospitals (Rahel and Sinai); attendants to a geriatric Day Club; and 26 old people with entirely independent households. The sera were examined by indirect immunofluorescence with antigens of sixLegionellaspecies (L. pneumophila, L. longbeachae, L. micdadei, L. gormanii, L. dumoffiiandL. bozemanii). A titre of ≥ 256 to at least one antigen was obtained in 30·5% of patients and 35·7% of staff members from Rahel; 12·1% of patients and 17·2% of staff members from Sinai; 9·1% of attendants to the Day Club; and none of 26 old people with their own households. All the positive patients from Rahel reacted withL. pneumophila, but only four of seven of the positive patients from Sinai did so; none of the seropositive subjects from the Day Club reacted with this agent.The results indicate intramural exposure to agents of legionellosis, at least for the Rahel Hospital.