title: Long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with Escherichia coli O157:H7: a prospective cohort study.
abstract: OBJECTIVE
  To evaluate the risk for hypertension, renal impairment, and cardiovascular disease within eight years of gastroenteritis from drinking water contaminated with Escherichia coli O157:H7 and Campylobacter.
  
  
  METHODS
  A prospective cohort study. Setting Walkerton, Ontario, Canada.
  
  
  METHODS
  1977 adult participants in the Walkerton Health Study recruited between 2002 and 2005 after an outbreak of gastroenteritis in May 2000, when a municipal water system was contaminated, with no pre-outbreak history of outcome measures.
  
  
  METHODS
  Information was collected annually via survey, physical examination, and laboratory assessment. Primary measures were acute gastroenteritis (diarrhoeal illness lasting >3 days, bloody diarrhoea, or >3 loose stools/day), hypertension (blood pressure ≥140/90 mm Hg), and renal impairment (microalbuminuria or estimated glomerular filtration rate <60 ml/min/1.73 m(2)). Self reported physician diagnosis of cardiovascular disease (myocardial infarction, stroke, or congestive heart failure) was a secondary outcome.
  
  
  RESULTS
  Acute gastroenteritis at the time of the outbreak was reported by 1067 (54%) of participants. Incident hypertension was detected in 697 (35%) (294 (32%) of group not exposed to acute gastroenteritis v 403 (38%) of exposed group). While 572 (29%) had at least one indicator of renal impairment (266 (29%) of unexposed v 306 (29%) of exposed), only 30 (1.5%) had both (8 (0.9%) of unexposed v 22 (2.1%) of exposed). Cardiovascular disease was reported by 33/1749 (1.9%). The adjusted hazard ratios for hypertension and cardiovascular disease after acute gastroenteritis were 1.33 (95% confidence interval 1.14 to 1.54) and 2.13 (1.03 to 4.43) respectively. The adjusted hazard ratio for the presence of either indicator of renal impairment was 1.15 (0.97 to 1.35) and was 3.41 (1.51 to 7.71) for the presence of both.
  
  
  CONCLUSIONS
  Gastroenteritis from drinking water contaminated with E coli O157:H7 and Campylobacter was associated with an increased risk for hypertension, renal impairment, and self reported cardiovascular disease. Annual monitoring of blood pressure and periodic monitoring of renal function may be warranted for individuals who experience E coli O157:H7 gastroenteritis.
authors.affiliation: Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, ON, Canada. William.Clark@lhsc.on.ca
authors.forename: William F
authors.initials: WF
authors.lastname: Clark
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Sontrop
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Macnab
authors.forename: Marina
authors.initials: M
authors.lastname: Salvadori
authors.forename: Louise
authors.initials: L
authors.lastname: Moist
authors.forename: Rita
authors.initials: R
authors.lastname: Suri
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
mesh_terms: D000328:Adult; D002169:Campylobacter Infections / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000453:epidemiology*; D019453:Escherichia coli O157; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000382:microbiology; D015994:Incidence; D007674:Kidney Diseases / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D014871:Water Microbiology; D014881:Water Supply / Q000706:statistics & numerical data*