Table 1.
Inclusion and exclusion criteria used to identify relevant outbreaks occurring in small drinking water systems (SDWS) in this review.
Fig 1.
PRISMA flow chart detailing the screening of literature through the systematic review process.
Reports of waterborne disease outbreaks in small drinking water systems in Canada and the United States between 1970–2014 were screened using this process.
Fig 2.
Frequency distribution of waterborne disease outbreaks in small drinking water systems (n = 286^).
Outbreaks reported in the literature, by month, in Canada and the United States (1970–2014). ^Seven outbreak reports did not indicate the month during which the outbreak occurred. *Count in summer months (June, July, August) was significantly different (P < 0.001) from number of outbreaks occurring in other seasons.
Fig 3.
Frequency distribution of etiologic agents in waterborne disease outbreaks in small drinking water systems.
Outbreaks reported in Canada and the United States (1970–2014) (n = 293). Other bacteria include: Salmonella spp (n = 6), E.coli O157:H7 (n = 3), Yersinia enterocolitica (n = 3), Streptococcus spp (n = 2), Bacillus cereus (n = 1) and Pseudomonas aeruginosa (n = 1). Other viruses include: Small Round Structured Viruses (SRSV) (n = 1) and Rotavirus (n = 2). Multiple agents included: Campylobacter jejuni and E. coli O157:H7 (n = 2); Campylobacter jejuni and Giardia intestinalis (n = 2); Campylobacter jejuni and Shigella sonnei (n = 1); Campylobacter jejuni and Norovirus (n = 1); and Campylobacter jejuni and Yersinia enterocolitica (n = 1).
Table 2.
Summary of number of illnesses and deaths by causative microorganism as reported in 293 waterborne disease outbreaks involving small drinking water systems in Canada and the United States (1970–2014).
Fig 4.
Bubble chart of reported waterborne disease outbreaks (n = 293) in small drinking water systems.
Outbreaks in Canada and the United States (1970–2014) stratified by water source and category of causative microorganism. Bubbles show the column percentages for each water source category, and their sizes are proportional to these values. *Other water sources include cistern and reservoir.
Fig 5.
Frequency distribution of reported waterborne disease outbreaks (n = 293) in small drinking water systems.
Outbreaks in Canada and the United States (1970–2014) stratified by treatment and water source. *Other water sources include cistern and reservoir.
Table 3.
Water system failure (n = 326) cited in 293 waterborne disease outbreak reports in small drinking water systems in Canada and the United States (1971–2014), stratified by water source.
Fig 6.
Premises type of reported waterborne disease outbreaks (n = 293) in small drinking water systems.
Outbreaks in Canada and the United States (1970–2014). *Other premises included tourist attraction (n = 11), special event (n = 10), retirement home (n = 7), recreation centre (n = 4), church (n = 4), cafeteria/catering (n = 4), ranch (n = 3), workplace (n = 3), hospital/daycare (n = 3), military base (n = 3), country club (n = 2), trailer park (n = 2), prison (n = 1), and supermarket (n = 1).
Table 4.
Recommended items to include when reporting outbreaks associated with small drinking water systems.