Waterborne norovirus outbreak in a municipal drinking-water supply in Sweden.
During Easter 2009, almost 200 people resident in a small Swedish village fell ill with gastrointestinal symptoms. We conducted a retrospective cohort study and a molecular investigation in order to identify the source of the outbreak. Residents living in households connected to the public water network were at an increased risk of developing disease (relative risk 4·80, 95% confidence interval 1·68-13·73) compared to those with no connection to the public network. Norovirus genotype GI.3 was identified in stool samples from six patients and in a sample from the public water network. Contamination of one of the wells supplying the public water network was thought to be the source of the outbreak. This is a description of a norovirus outbreak linked to a municipal drinking-water supply in Sweden. Information from epidemiological and molecular investigations is of utmost importance to guide outbreak control measures and to prevent future outbreaks.
European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
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M
Riera-Montes
K
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Brus Sjölander
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G
Allestam
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E
Hallin
K-O
KO
Hedlund
M
M
Löfdahl
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004196:Disease Outbreaks / Q000517:prevention & control; D060766:Drinking Water / Q000821:virology*; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D029322:Norovirus / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
D060766:Drinking Water; D012367:RNA, Viral