Alternative routes for dissemination of Legionella pneumophila causing three outbreaks in Norway.
Three outbreaks of Legionnaires' disease were reported in the Fredrikstad/Sarpsborg community, Norway, in 2005 and 2008 caused by the L. pneumophila ST15 and ST462 strains determined by sequence based typing. In this retrospective study, we suggest that the aeration ponds, a part of the biological treatment plant at Borregaard Ind. Ltd., are the main amplifiers and primary disseminators of the outbreak L. pneumophila strains. This result is supported by the finding that the ST15 and ST462 strains were not able to survive in air scrubber liquid media more than two days of incubation at the scrubber's operating conditions during the 2005 and 2008 outbreaks. In 2008, >10¹⁰ CFU/L of L. pneumophila ST462 were detected in the aeration ponds. ST15 and ST462 were also detected in the river Glomma in 2005 and 2008, respectively, downstream of the wastewater outlet from the treatment plant (10⁵CFU/L). These findings strongly suggest that the presence of L. pneumophila in the river is due to the release of wastewater from the industrial aeration ponds, demonstrating that the river Glomma may be an additional disseminator of L. pneumophila during the outbreaks. This work emphasizes the need for preventive actions against the release of wastewater containing human pathogens to the environment.
Olsen
Jaran Strand
JS
Norwegian Defence Research Establishment (FFI), Norway.
Aarskaug
Tone
T
Thrane
Ingjerd
I
Pourcel
Christine
C
Ask
Eirik
E
Johansen
Gisle
G
Waagen
Viggo
V
Blatny
Janet Martha
JM
D015373:Bacterial Typing Techniques; D001673:Biodegradation, Environmental; D004196:Disease Outbreaks / Q000706:statistics & numerical data; D006801:Humans; D016952:Legionella pneumophila / Q000145:classification / Q000254:growth & development* / Q000302:isolation & purification; D007877:Legionnaires' Disease / Q000635:transmission*; D009664:Norway / Q000453:epidemiology; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis
D014873:Water Pollutants