Community spread of Legionella pneumophila serogroup 1 in temporal relation to a nosocomial outbreak.
To clarify whether a nosocomial outbreak of legionnaires' disease in the Värnamo hospital in Sweden was part of a wider outbreak in the Värnamo community a number of investigations were performed. First, the proportion of cases of legionnaires' disease in a group with nosocomially acquired pneumonia (11%) was compared to the proportion within a group with community-acquired pneumonia (14%) and the difference was found not to be significant (p > 0.05). Second, the proportion of the nursing staff at the Värnamo hospital with an elevated antibody titre (> or = 16) to Legionella pneumophila serogroup (sg) 1 (33%, 84/258) was compared to the proportion in a group of local residents of Värnamo community (26%, 25/96) and found not to be significant; in contrast, comparison with the proportion in a group from the assistant nursing staff at another hospital 60 km away (5%, 4/80) was highly significant (p < 0.001). Furthermore, Legionella species were cultured from samples drawn from the hospital water supply as well from the water supply from municipal buildings. In 1996 a follow-up study was conducted, which showed that < 1% of the assistant nurses and local residents had an elevated titre to L. pneumophila sg 1. These results indicate that there was a temporary spread of L. pneumophila sg 1 in the Värnamo community at the beginning of 1991, both in the local hospital and the surrounding community. This implies that physicians should be aware of community-acquired cases of legionnaires' disease when a nosocomial outbreak is detected.
Darelid
J
J
Department of Infectious Diseases, Ryhov Hospital, Jönköping, Sweden.
Hallander
H
H
Löfgren
S
S
Malmvall
B E
BE
Olinder-Nielsen
A M
AM
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D016952:Legionella pneumophila / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D008297:Male; D009728:Nursing Assistants; D009784:Occupational Diseases / Q000453:epidemiology / Q000382:microbiology; D012621:Seasons; D016036:Seroepidemiologic Studies; D012703:Serotyping; D013548:Sweden / Q000453:epidemiology; D014871:Water Microbiology; D014881:Water Supply
D000907:Antibodies, Bacterial