Rainfall and outbreaks of drinking water related disease and in England and Wales

Abstract

A case-crossover study compared rainfall in the 4 weeks before drinking water related outbreaks with that in the five previous control years. This included public and private drinking water related outbreaks in England and Wales from 1910 to 1999. Of 111 outbreaks, 89 met inclusion criteria and the implicated pathogens included Giardia, Cryptosporidium, E. coli, S. Typhi, S. Paratyphi, Campylobacter and Streptobacillus moniliformis. Weather data was derived from the British Atmospheric Data Centre There was a significant association between excess cumulative rainfall in the previous 7 days and outbreaks ( p ¼ 0.001). There was an excess of rainfall below 20 mm for the three weeks previous to this in outbreak compared to control weeks ( p ¼ 0.002). Cumulative rainfall exceedances were associated with outbreak years. This study provides evidence that both low rainfall and heavy rain precede many drinking water outbreaks and assessing the health impacts of climate change should examine both.

Longitudinal Evaluation of Enteric Protozoa in Haitian Children by Stool Exam and Multiplex Serologic Assay

“…16 Rain has been shown to be an important risk factor for waterborne diseases, particularly in settings where sanitation is sub-optimal. [33][34][35] These data highlight the importance of controlling for seasonality in sero-epidemiologic studies of these infections.…”

Impact of El Niño Southern Oscillation on infectious disease hospitalization risk in the United States

“…If this finding is valid, it yields a key insight into the potential impact of environmental impacts on infectious disease risk: A given environmental change may result in different effects on disease risk in different ecosystems. It has been noted that both unusually wet and unusually dry conditions may enhance enteric disease risk (42). In the Southwestern United States, major metropolitan areas are dependent on reservoirs and aquifers (43,44), which may be depleted in drought conditions, with concentration of nutrients and pathogens; by contrast, other regions that depend more heavily on surface waters may be vulnerable to runoff that attends heavier rainfalls.…”

Impact of climate change on waterborne diseases

“…There are several examples of waterborne diseases outbreaks associated to excessive rainfall [31][32][33][34][35][36][37][38][39][40][41][42][43]. The largest reported waterborne disease outbreak in the United States, due to the presence of Cryptosporidium cists in drinking water, occurred in Milwaukee in 1993 and was related to heavy rainfall and associated runoff and consequent contamination of Milwaukee lake, the source of the waterworks of the area.…”

“…Only 24% of waterborne pathogen outbreaks in England, between 1970 and 2000, were found associated to heavy rainfall [48]. Yet, Nichols et al [36] analyzing a small dataset [89] of waterborne outbreaks in England and Wales between 1910-1999, due to Giardia, Cryptosporidium, E. coli, S. typhi, S. paratyphi, Campylobacter and Streptobacillus moniliformis, assessed a significant strong correlation between 40% of the cases and heavy rainfall in the week before the outbreak or low rainfall during the four weeks preceding the outbreaks.…”