title: Summer increase of Legionnaires' disease 2010 in The Netherlands associated with weather conditions and implications for source finding.
abstract: During August and September 2010 an unexpected high number of domestic cases of Legionnaires' disease (LD) were reported in The Netherlands. To examine this increase, patient characteristics and results of source finding and environmental sampling during the summer peak were compared to other domestic cases in 2008-2011. This analysis did not provide an explanation for the rise in cases. A similar increase in LD cases in 2006 was shown to be associated with warm and wet weather conditions, using an extended Poisson regression model with adjustment for long-term trends. This model was optimized with the new data from 2008 to 2011. The increase in 2010 was very accurately described by a model, which included temperature in the preceding 4 weeks, and precipitation in the preceding 2 weeks. These results confirm the strong association of LD incidence with weather conditions, but it remains unclear which environmental sources contributed to the 2010 summer increase.
authors.affiliation: Centre for Infectious Diseases,Epidemiology and Surveillance,National Institute for Public Health and the Environment,Bilthoven,The Netherlands.
authors.forename: P S
authors.initials: PS
authors.lastname: Brandsema
authors.affiliation: Regional Public Health Laboratory Kennemerland,Haarlem,The Netherlands.
authors.forename: S M
authors.initials: SM
authors.lastname: Euser
authors.affiliation: Department for Infectious Disease Epidemiology,Respiratory Infections Unit,Robert Koch Institute, Berlin,Germany.
authors.forename: I
authors.initials: I
authors.lastname: Karagiannis
authors.affiliation: Regional Public Health Laboratory Kennemerland,Haarlem,The Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Den Boer
authors.affiliation: Centre for Infectious Diseases,Epidemiology and Surveillance,National Institute for Public Health and the Environment,Bilthoven,The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Van Der Hoek
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D002980:Climate; D003141:Communicable Diseases / Q000453:epidemiology*; D004196:Disease Outbreaks; D004777:Environment; D005260:Female; D006801:Humans; D015994:Incidence; D007877:Legionnaires' Disease / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands / Q000453:epidemiology; D016012:Poisson Distribution; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D017678:Sex Distribution; D013696:Temperature