Outbreaks Open Access
Like 0


On 6 June 2019, the Norwegian Institute of Public Health was notified of more than 50 cases of gastroenteritis in Askøy. A reservoir in a water supply system was suspected as the source of the outbreak because of the acute onset and geographical distribution of cases. We investigated the outbreak to confirm the source, extent of the outbreak and effect of control measures. A case was defined as a person in a household served by Water Supply System A (WSS-A) who had gastroenteritis for more than 24 h between 1 and 19 June 2019. We conducted pilot interviews, a telephone survey and an SMS-based cohort study of residents served by WSS-A. System information of WSS-A was collected. Whole genome sequencing on human and environmental isolates was performed. Among 6,108 individuals, 1,573 fulfilled the case definition. Residents served by the reservoir had a 4.6× higher risk of illness than others. isolated from cases (n = 24) and water samples (n = 4) had identical core genome MLST profiles. Contamination through cracks in the reservoir most probably occurred during heavy rainfall. Water supply systems are susceptible to contamination, particularly to certain weather conditions. This highlights the importance of water safety planning and risk-based surveillance to mitigate risks.


Article metrics loading...

Loading full text...

Full text loading...



  1. World Health Organization (WHO). Campylobacter. Key facts. Geneva: WHO. [Accessed: May 2020]. Available from: https://www.who.int/news-room/fact-sheets/detail/campylobacter
  2. Silva J, Leite D, Fernandes M, Mena C, Gibbs PA, Teixeira P. Campylobacter spp. as a foodborne pathogen: a review. Front Microbiol. 2011;2:200.  https://doi.org/10.3389/fmicb.2011.00200  PMID: 21991264 
  3. Kaakoush NO, Castaño-Rodríguez N, Mitchell HM, Man SM. Global epidemiology of campylobacter infection. Clin Microbiol Rev. 2015;28(3):687-720.  https://doi.org/10.1128/CMR.00006-15  PMID: 26062576 
  4. Kapperud G, Espeland G, Wahl E, Walde A, Herikstad H, Gustavsen S, et al. Factors associated with increased and decreased risk of Campylobacter infection: a prospective case-control study in Norway. Am J Epidemiol. 2003;158(3):234-42.  https://doi.org/10.1093/aje/kwg139  PMID: 12882945 
  5. Jakopanec I, Borgen K, Vold L, Lund H, Forseth T, Hannula R, et al. A large waterborne outbreak of campylobacteriosis in Norway: the need to focus on distribution system safety. BMC Infect Dis. 2008;8(1):128.  https://doi.org/10.1186/1471-2334-8-128  PMID: 18816387 
  6. Sandberg M, Nygård K, Meldal H, Valle PS, Kruse H, Skjerve E. Incidence trend and risk factors for campylobacter infections in humans in Norway. BMC Public Health. 2006;6(1):179.  https://doi.org/10.1186/1471-2458-6-179  PMID: 16827925 
  7. Mac Kenzie WR, Hoxie NJ, Proctor ME, Gradus MS, Blair KA, Peterson DE, et al. A massive outbreak in Milwaukee of cryptosporidium infection transmitted through the public water supply. N Engl J Med. 1994;331(3):161-7.  https://doi.org/10.1056/NEJM199407213310304  PMID: 7818640 
  8. O’Connor DR. Report of the Walkerton inquiry: The events of May 2000 and related issues: A summary. Toronto: Ministry of the Attorney General; 2002. Report No.: 0779425588. Available from: http://www.archives.gov.on.ca/en/e_records/walkerton/index.html
  9. Widerström M, Schönning C, Lilja M, Lebbad M, Ljung T, Allestam G, et al. Large outbreak of Cryptosporidium hominis infection transmitted through the public water supply, Sweden. Emerg Infect Dis. 2014;20(4):581-9.  https://doi.org/10.3201/eid2004.121415  PMID: 24655474 
  10. Moreira NA, Bondelind M. Safe drinking water and waterborne outbreaks. J Water Health. 2017;15(1):83-96.  https://doi.org/10.2166/wh.2016.103  PMID: 28151442 
  11. World Health Organization (WHO). Guidelines for drinking-water quality, 3rd edition: Volume 1 - Recommendations. Geneva: WHO; 2004. Available from: https://www.who.int/water_sanitation_health/publications/gdwq3/en/
  12. Ercumen A, Gruber JS, Colford JM Jr. Water distribution system deficiencies and gastrointestinal illness: a systematic review and meta-analysis. Environ Health Perspect. 2014;122(7):651-60.  https://doi.org/10.1289/ehp.1306912  PMID: 24659576 
  13. Nygård K, Wahl E, Krogh T, Tveit OA, Bøhleng E, Tverdal A, et al. Breaks and maintenance work in the water distribution systems and gastrointestinal illness: a cohort study. Int J Epidemiol. 2007;36(4):873-80.  https://doi.org/10.1093/ije/dym029  PMID: 17389718 
  14. European Food Safety Authority and European Centre for Disease Prevention and Control (EFSA and ECDC). The European Union One Health 2018 Zoonoses Report. Parma: EFSA; Stockholm: ECDC; 2019. Available from: https://www.ecdc.europa.eu/sites/default/files/documents/zoonoses-EU-one-health-2018-report.pdf
  15. Guzman-Herrador B, de Blasio BF, Lund V, MacDonald E, Vold L, Wahl E, et al. Vannbårne utbrudd i Norge i perioden 2003-12. [Waterborne outbreaks in Norway 2003-2012]. Tidsskr Nor Laegeforen. 2016;136(7):612-6. Norwegian.  https://doi.org/10.4045/tidsskr.15.0114  PMID: 27094662 
  16. Guzman-Herrador B, Carlander A, Ethelberg S, Freiesleben de Blasio B, Kuusi M, Lund V, et al. Waterborne outbreaks in the Nordic countries, 1998 to 2012. Euro Surveill. 2015;20(24):21160.  https://doi.org/10.2807/1560-7917.ES2015.20.24.21160  PMID: 26111239 
  17. Nygård K, Schimmer B, Søbstad Ø, Walde A, Tveit I, Langeland N, et al. A large community outbreak of waterborne giardiasis-delayed detection in a non-endemic urban area. BMC Public Health. 2006;6(1):141.  https://doi.org/10.1186/1471-2458-6-141  PMID: 16725025 
  18. Jolley KA, Bray JE, Maiden MCJ. Open-access bacterial population genomics: BIGSdb software, the PubMLST.org website and their applications. Wellcome Open Res. 2018;3:124.  https://doi.org/10.12688/wellcomeopenres.14826.1  PMID: 30345391 
  19. Cody AJ, McCarthy ND, Jansen van Rensburg M, Isinkaye T, Bentley SD, Parkhill J, et al. Real-time genomic epidemiological evaluation of human Campylobacter isolates by use of whole-genome multilocus sequence typing. J Clin Microbiol. 2013;51(8):2526-34.
  20. Lahti E, Rehn M, Ockborn G, Hansson I, Ågren J, Engvall EO, et al. Outbreak of campylobacteriosis following a dairy farm visit: confirmation by genotyping. Foodborne Pathog Dis. 2017;14(6):326-32.  https://doi.org/10.1089/fpd.2016.2257  PMID: 28350214 
  21. Lovdata. Forskrift om vannforsyning og drikkevann (drikkevannsforskriften). [The Norwegian legislation on water supply and drinking water]. Oslo: Lovdata; 2017. Norwegian. Available from: https://lovdata.no/dokument/LTI/forskrift/2016-12-22-1868
  22. Rosenquist H, Bengtsson A, Hansen TB. A collaborative study on a Nordic standard protocol for detection and enumeration of thermotolerant Campylobacter in food (NMKL 119, 3. Ed., 2007). Int J Food Microbiol. 2007;118(2):201-13.  https://doi.org/10.1016/j.ijfoodmicro.2007.07.037  PMID: 17761333 
  23. Braeye T, DE Schrijver K, Wollants E, van Ranst M, Verhaegen J. A large community outbreak of gastroenteritis associated with consumption of drinking water contaminated by river water, Belgium, 2010. Epidemiol Infect. 2015;143(4):711-9.  https://doi.org/10.1017/S0950268814001629  PMID: 25062494 
  24. Gubbels SM, Kuhn KG, Larsson JT, Adelhardt M, Engberg J, Ingildsen P, et al. A waterborne outbreak with a single clone of Campylobacter jejuni in the Danish town of Køge in May 2010. Scand J Infect Dis. 2012;44(8):586-94.  https://doi.org/10.3109/00365548.2012.655773  PMID: 22385125 
  25. Bruce-Grey-Owen Sound Health Unit. Waterborne outbreak of gastroenteritis associated with a contaminated municipal water supply, Walkerton, Ontario, May-June 2000. Can Commun Dis Rep. 2000;26(20):170-3. PMID: 11211701 
  26. Bartholomew N, Brunton C, Mitchell P, Williamson J, Gilpin B. A waterborne outbreak of campylobacteriosis in the South Island of New Zealand due to a failure to implement a multi-barrier approach. J Water Health. 2014;12(3):555-63.  https://doi.org/10.2166/wh.2014.155  PMID: 25252359 
  27. Kuhn KG, Falkenhorst G, Emborg HD, Ceper T, Torpdahl M, Krogfelt KA, et al. Epidemiological and serological investigation of a waterborne Campylobacter jejuni outbreak in a Danish town. Epidemiol Infect. 2017;145(4):701-9.  https://doi.org/10.1017/S0950268816002788  PMID: 27903324 
  28. Mouly D, Van Cauteren D, Vincent N, Vaissiere E, Beaudeau P, Ducrot C, et al. Description of two waterborne disease outbreaks in France: a comparative study with data from cohort studies and from health administrative databases. Epidemiol Infect. 2016;144(3):591-601.  https://doi.org/10.1017/S0950268815001673  PMID: 26194500 
  29. Kuusi M, Klemets P, Miettinen I, Laaksonen I, Sarkkinen H, Hänninen ML, et al. An outbreak of gastroenteritis from a non-chlorinated community water supply. J Epidemiol Community Health. 2004;58(4):273-7.  https://doi.org/10.1136/jech.2003.009928  PMID: 15026434 
  30. Kuusi M, Nuorti JP, Hänninen ML, Koskela M, Jussila V, Kela E, et al. A large outbreak of campylobacteriosis associated with a municipal water supply in Finland. Epidemiol Infect. 2005;133(4):593-601.  https://doi.org/10.1017/S0950268805003808  PMID: 16050503 
  31. Karagiannis I, Sideroglou T, Gkolfinopoulou K, Tsouri A, Lampousaki D, Velonakis EN, et al. A waterborne Campylobacter jejuni outbreak on a Greek island. Epidemiol Infect. 2010;138(12):1726-34.  https://doi.org/10.1017/S0950268810002116  PMID: 20836911 
  32. Laine J, Huovinen E, Virtanen MJ, Snellman M, Lumio J, Ruutu P, et al. An extensive gastroenteritis outbreak after drinking-water contamination by sewage effluent, Finland. Epidemiol Infect. 2011;139(7):1105-13.  https://doi.org/10.1017/S0950268810002141  PMID: 20843387 
  33. Hrudey SE, Hrudey EJ. Published case studies of waterborne disease outbreaks—evidence of a recurrent threat. Water Environ Res. 2007;79(3):233-45.
  34. Hrudey SE, Conant B, Douglas IP, Fawell J, Gillespie T, Hill D, et al. Managing uncertainty in the provision of safe drinking water. Water Sci Technol Water Supply. 2011;11:675. . Available from: https://cwn-rce.ca/wp-content/uploads/2014/06/managing-uncertainty-in-the-provision-of-safe-drinking-water.pdf https://doi.org/10.2166/ws.2011.075 
  35. Rizak S, Hrudey SE. Achieving safe drinking water — risk management based on experience and reality. Environ Rev. 2007;15(1):169-74.
  36. Rizak S, Hrudey SE. Evidence of water quality monitoring limitations for outbreak detection. Environ Health. 2007;7(1):11-21.
  37. Storey MV, van der Gaag B, Burns BP. Advances in on-line drinking water quality monitoring and early warning systems. Water Res. 2011;45(2):741-7.  https://doi.org/10.1016/j.watres.2010.08.049  PMID: 20851446 
  38. World Health Organization Regional Office for Europe (WHO/Europe). Strengthening drinking-water surveillance using risk-based approaches. Copenhagen: WHO/Europe; 2019. Available from: http://www.euro.who.int/en/health-topics/environment-and-health/water-and-sanitation/publications/2019/strengthening-drinking-water-surveillance-using-risk-based-approaches-2019
  39. Widerström M, Schönning C, Lilja M, Lebbad M, Ljung T, Allestam G, et al. Large outbreak of Cryptosporidium hominis infection transmitted through the public water supply, Sweden. Emerg Infect Dis. 2014;20(4):581-9.  https://doi.org/10.3201/eid2004.121415  PMID: 24655474 
  40. Andersson T, Bjelkmar P, Hulth A, Lindh J, Stenmark S, Widerström M. Syndromic surveillance for local outbreak detection and awareness: evaluating outbreak signals of acute gastroenteritis in telephone triage, web-based queries and over-the-counter pharmacy sales. Epidemiol Infect. 2014;142(2):303-13.  https://doi.org/10.1017/S0950268813001088  PMID: 23672877 
  41. Shortridge JE, Guikema SD. Public health and pipe breaks in water distribution systems: analysis with internet search volume as a proxy. Water Res. 2014;53:26-34.  https://doi.org/10.1016/j.watres.2014.01.013  PMID: 24495984 
  42. Bjelkmar P, Hansen A, Schönning C, Bergström J, Löfdahl M, Lebbad M, et al. Early outbreak detection by linking health advice line calls to water distribution areas retrospectively demonstrated in a large waterborne outbreak of cryptosporidiosis in Sweden. BMC Public Health. 2017;17(1):328.  https://doi.org/10.1186/s12889-017-4233-8  PMID: 28420373 
  43. United States Environmental Protection Agency (EPA). Water quality surveillance and response. Washington DC: EPA. [Accessed: 8 Jun 2020]. Available from: https://www.epa.gov/waterqualitysurveillance

Data & Media loading...

Submit comment
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error