A gradient of acute gastroenteritis was characterized, to assess risk of long-term health sequelae after drinking bacterial-contaminated water

Garg, Amit X.; Marshall, John; Salvadori, Marina; Thiessen-Philbrook, Heather R.; Macnab, Jennifer; Suri, Rita S.; Haynes, R. Brian; Pope, Janet; Clark, William; on behalf of the Walkerton Health Study Investigators,

doi:10.1016/j.jclinepi.2005.08.014

« Previous Next »Journal of Clinical Epidemiology
Volume 59, Issue 4 , Pages 421-428, April 2006

A gradient of acute gastroenteritis was characterized, to assess risk of long-term health sequelae after drinking bacterial-contaminated water

Amit X. Garg
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
- Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
- Present address: London Kidney Clinical Research Unit, Room ELL-101, Westminster Tower, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 4G5, Canada.
- Corresponding author. Tel.: 519-685-8502; fax: 519-685-8072.
John Marshall
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
Marina Salvadori
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
Heather R. Thiessen-Philbrook
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
Jennifer Macnab
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
- Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada
Rita S. Suri
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
R. Brian Haynes
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
Janet Pope
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
- Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada
William Clark
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
on behalf of the Walkerton Health Study Investigators
- The Walkerton Health Study Investigators: William Clark, Steve Collins, Amit Garg, R. Brian Haynes, John Howard, Jennifer Macnab, Jeff Mahon, John Marshall, Douglas Matsell, Louise Moist, Janet Pope, Joel Ray, Patricia Rosas-Arellano, Marina Salvadori, and Rita Suri.

Accepted 29 August 2005. published online 01 February 2006.

Abstract

Objective

A municipal water system became contaminated with Escherichia coli O157:H7 and Campylobacter spp. Beginning 2 years after an outbreak, all residents from the region were invited to participate in a cohort study assessing the risk of long-term sequelae. We aimed to develop a method to grade the accuracy and severity of self-reported acute symptoms.

Study Design and Setting

We corroborated participant survey responses with health records at the time of the outbreak. Of the 4,135 participants, 1,388 were asymptomatic during the outbreak, 1,752 had symptoms of acute self-limited gastroenteritis that could neither be confirmed nor refuted by prior health records, and 995 had symptoms that necessitated medical attention (and thus were confirmed by prior health records).

Results

The gradient related to the severity of acute symptoms. Compared to those with unconfirmed gastroenteritis, participants with confirmed gastroenteritis were more likely to describe fever, bloody diarrhea, and prolonged diarrhea (all P < .03). The gradient also correlated with long-term plausible outcomes, including chronic gastrointestinal symptoms, chronic symptoms of arthritis or depression, and the avoidance of municipal water ingestion after the outbreak (P for trend consistently < .03). Conversely, for the outcome of chronic tinnitus, an association was neither expected nor observed (P for trend = .26).