Acute gastrointestinal illness burden associated with water recreation in high-income countries: A scoping review.

Objectives: The burden of acute gastrointestinal illness (AGI) attributable to natural water recreation in Canada is unknown. Understanding the burden can help prioritize public health interventions and resource allocation for reduction of disease. Our objectives were to compile estimates of AGI burden associated with natural water recreation, identify knowledge gaps in water recreation epidemiology, and evaluate methods applicable for developing a burden estimate for Canada.

Methods: We conducted a scoping review of the literature. From a total of 2752 unique records identified, 35 met eligibility for inclusion. Articles were chosen if they examined burden in natural waterways, were written in English, and were based in countries of similar economic status to Canada in non-tropical regions. Burden was defined as either: incidence or prevalence, disability-adjusted life years (DALYs), quality-adjusted life years (QALYs), or economic cost.

Results: Swimming or wading were the predominant forms of recreation examined (n = 32/35; 91.4%). Waterways studied were primarily marine or coastal beaches (n = 24/35; 68.6%) and were located within or adjacent to urban areas (n = 29/35; 82.9%). The most common indicator for burden was incidence or prevalence (n = 30/35; 85.7%). Prospective cohort studies (n = 17/35; 48.6%) and predictive modelling based on microorganism concentrations (n = 9/35; 25.7%) were the most common methods of estimation.

Conclusion: The review highlighted several knowledge gaps regarding recreational waterborne disease burden. Freshwater recreation, rural waterways, and recreational activities other than swimming and wading require further study. We propose that quantitative microbial risk assessment may be an appropriate, cost-effective method to estimate recreational waterborne disease burden in Canada.