A Systematic Review of Waterborne Disease Outbreaks Associated with Small Non-Community Drinking Water Systems in Canada and the United States

Abstract

BackgroundReports of outbreaks in Canada and the United States (U.S.) indicate that approximately 50% of all waterborne diseases occur in small non-community drinking water systems (SDWSs). Summarizing these investigations to identify the factors and conditions contributing to outbreaks is needed in order to help prevent future outbreaks.ObjectivesThe objectives of this study were to: 1) identify published reports of waterborne disease outbreaks involving SDWSs in Canada and the U.S. since 1970; 2) summarize reported factors contributing to outbreaks, including water system characteristics and events surrounding the outbreaks; and 3) identify terminology used to describe SDWSs in outbreak reports.MethodsThree electronic databases and grey literature sources were searched for outbreak reports involving SDWSs throughout Canada and the U.S. from 1970 to 2014. Two reviewers independently screened and extracted data related to water system characteristics and outbreak events. The data were analyzed descriptively with ‘outbreak’ as the unit of analysis.ResultsFrom a total of 1,995 citations, we identified 50 relevant articles reporting 293 unique outbreaks. Failure of an existing water treatment system (22.7%) and lack of water treatment (20.2%) were the leading causes of waterborne outbreaks in SDWSs. A seasonal trend was observed with 51% of outbreaks occurring in summer months (p<0.001). There was large variation in terminology used to describe SDWSs, and a large number of variables were not reported, including water source and whether water treatment was used (missing in 31% and 66% of reports, respectively).ConclusionsMore consistent reporting and descriptions of SDWSs in future outbreak reports are needed to understand the epidemiology of these outbreaks and to inform the development of targeted interventions for SDWSs. Additional monitoring of water systems that are used on a seasonal or infrequent basis would be worthwhile to inform future protection efforts.

Relationship Between Operational Characteristics of Small Non-Community Drinking Water Systems and Adverse Water Quality Incidents in Southern Ontario, Canada

“…Pons et al (2015) reported that having no treatment system is one of the leading causes of outbreaks in SDWSs. Edwards et al (2012) examined the safe operation characteristics of small commercial water systems in British Columbia, Canada, and concluded that the lack of a treatment system and water source vulnerability are among factors causing adverse conditions in SDWSs.…”

“…In simple terms, drinking water is considered safe when it does not contain pathogens or unsafe concentrations of toxic chemicals or radioactive substances (MOE, 2006). Although approximately 15% of Canadians use Small Non-Community Drinking Water Systems (SDWSs), more than 50% of the waterborne outbreaks in Canada are associated with these systems (Pons et al, 2015). This study aims to examine the SDWS operational characteristics and their relationships with Adverse Water Quality Incidents (AWQIs).…”

“…In other words, 'the environment' or water source is not the major contributing factor, it is human and technological deficiencies. Pons et al (2015) notes that etiology was not identified in more than half of the reported waterborne outbreaks in Canada and the United States between 1970 and 2014 whilst, Giardia intestinalis was the most commonly identified pathogen followed by Norovirus and Campylobacter jejuni respectively. Enhanced reporting and identification of waterborne outbreaks would contribute to the explanation of the region's general characteristics and initiate strategies to prevent future occurrences.…”

Drinking Water Quality Influence to the Peasants’ Morbidity in the Ukrainian Settlements (by the Results of Sociological Survey and Correlation Analyses)

“…From a total of 1,995 citations, we identified 50 relevant articles reporting 293 unique outbreaks. Failure of an existing water treatment system (22.7%) and lack of water treatment (20.2%) were the leading causes of waterborne outbreaks in SDWSs [2].…”

Comparison of the Quality of Various Sources of Drinking Water Available in Mathura, Uttar Pradesh

“…Disease burden from unsafe water, sanitation and hygiene (WSH) accounts for 5.3% of all deaths and 6.8% of all DALYS all over the world (Pruss- Ustam et al, 2002). Despite wealthy economies and access to proven drinking water-treatment technologies, significant outbreaks of waterborne intestinal diseases have also occurred in developed countries of North America and Western Europe over the last 10-15 years (Pons et al, 2015). In 2011, around 768 million people relied on unsatisfactory water supply having high levels of pathogen contamination (WHO and UNICEF, 2013).…”