title: Risk of hypertension and reduced kidney function after acute gastroenteritis from bacteria-contaminated drinking water.
abstract: BACKGROUND
  The long-term health consequences of acute bacterial gastroenteritis remain uncertain. We studied the risk of hypertension and reduced kidney function after an outbreak of acute gastroenteritis due to contamination of a regional drinking water supply with Escherichia coli O157:H7 and Campylobacter species.
  
  
  METHODS
  A total of 1958 adults with no known history of hypertension or kidney disease before the outbreak participated in a long-term follow-up study. Of the participants, 675 had been asymptomatic during the outbreak, 909 had had moderate symptoms of acute self-limited gastroenteritis, and 374 had had severe symptoms that necessitated medical attention. The outcomes of interest were a diagnosis of hypertension or the presence of reduced kidney function and albuminuria during the follow-up period.
  
  
  RESULTS
  After a mean follow-up of 3.7 years after the outbreak, hypertension was diagnosed in 27.0% of participants who had been asymptomatic during the outbreak and in 32.3% and 35.9% of those who had had moderate and severe symptoms of acute gastroenteritis respectively (trend p = 0.009). Compared with the asymptomatic participants, those with moderate and severe symptoms of gastroenteritis had an adjusted relative risk of hypertension of 1.15 (95% confidence interval [CI] 0.97-1.35) and 1.28 (95% CI 1.04-1.56) respectively. A similar graded association was seen for reduced kidney function, defined as the presence of an estimated glomerular filtration rate below 60 mL/min per 1.73 m2 (trend p = 0.03). No association was observed between gastroenteritis and the subsequent risk of albuminuria.
  
  
  CONCLUSIONS
  Acute bacterial gastroenteritis necessitating medical attention was associated with an increased risk of hypertension and reduced kidney function 4 years after infection. Maintaining safe drinking water remains essential to human health, as transient bacterial contaminations may have implications well beyond a period of acute self-limited illness.
authors.affiliation: Division of Nephrology, University of Western Ontario, London, Ont. amit.garg@lhsc.on.ca
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.forename: Louise
authors.initials: L
authors.lastname: Moist
authors.forename: Douglas
authors.initials: D
authors.lastname: Matsell
authors.forename: Heather R
authors.initials: HR
authors.lastname: Thiessen-Philbrook
authors.forename: R Brian
authors.initials: RB
authors.lastname: Haynes
authors.forename: Rita S
authors.initials: RS
authors.lastname: Suri
authors.forename: Marina
authors.initials: M
authors.lastname: Salvadori
authors.forename: Joel
authors.initials: J
authors.lastname: Ray
authors.forename: William F
authors.initials: WF
authors.lastname: Clark
mesh_terms: D000208:Acute Disease; D000328:Adult; D002169:Campylobacter Infections / Q000150:complications*; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D005759:Gastroenteritis / Q000150:complications* / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D007674:Kidney Diseases / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D012307:Risk Factors; D012424:Rural Population; D014871:Water Microbiology; D014881:Water Supply