Swimming and other water activities at public beaches are increasingly popular leisure activities among Canadians. However, these activities can lead to increased risks of acquiring acute gastrointestinal illness and respiratory, skin, ear, and eye infections among beachgoers. These illnesses have a significant health and economic burden on society, with young children having much higher rates of illness than other age groups. Currently, baseline data are lacking on the risk of recreational water illness in Canada, and beachgoers may lack awareness and understanding of these risks and how to prevent them. This study will identify the burden of recreational water illness among Canadian beachgoers. The results will be used to develop recommendations for improving recreational water quality guidelines for safe swimming in Canada, as well as public health risk management and communication strategies with beachgoers. The study will use a mixed-methods approach, consisting of a prospective cohort study and a qualitative study of beachgoers. The investigators will determine the risk of acquiring recreational water illness outcomes in beachgoers that engage in different levels of water and sand contact. The investigators will examine differences in illness risks by beachgoer gender, age, and location. The investigators will examine relationships between fecal indicator bacteria (E. coli), environmental conditions, and host-specific biomarkers with the risk of gastrointestinal illness among beachgoers. The investigators will also evaluate beachgoer risk perceptions and behaviours toward recreational water quality. The study will take place at five targeted beach sites in British Columbia, Manitoba, and Ontario. The study will be coordinated by a multidisciplinary research team, with activities guided by a stakeholder steering group consisting of key knowledge users. The long-term goal is to reduce the burden of recreational water illness in Canada, contributing to improved public health.

Swimming and other beach water activities are increasingly popular outdoor leisure activities among Canadians. However, these activities increase the risk of acquiring acute gastrointestinal illness (AGI) and other acute illnesses among beachgoers. Recreational water illness (RWI) has a significant health burden, with young children having the highest rates of illness. These illnesses result in substantial costs to society due to healthcare costs and lost productivity. Data are lacking in Canada on the risk and burden of RWI, and beachgoers may lack awareness and understanding of RWI risks and how to prevent them. There is a critical need to conduct timely research on the burden of RWI in Canada to inform recreational water quality guidelines and public health risk management.

The purpose of this study is to identify the burden of RWI among Canadian beachgoers and to develop recommendations for improving recreational water quality risk management, communication, and pollution source prevention. The objectives are to:

1. Measure the risk and burden of five different RWI outcomes (AGI, respiratory, eye, ear, and skin infections) in beachgoers that engage in different levels of water and sand contact;
2. Identify differences in RWI risks by beachgoer gender, age, and beach location;
3. Determine relationships between fecal indicator bacteria, environmental parameters, host-specific biomarkers, and the risk of AGI among beachgoers; and
4. Understand beachgoer risk perceptions and behaviours related to recreational water quality and socio-political issues that may impact RWI risks among beachgoers.

The study will use a mixed-methods approach, consisting of a prospective cohort study (Objectives 1-3) with embedded qualitative research (Objective 4). The cohort study will involve enrolling participants at public beaches, ascertaining their water and sand contact exposure status, then following-up to determine the incidence of acute RWI outcomes. The investigators will combine beachgoer exposure data with routinely collected secondary data on environmental parameters and E. coli levels in beach water. The investigators will also test for enterococci as another fecal indicator using rapid molecular methods and will conduct microbial source tracking to determine the contribution of different sources of fecal contamination (e.g., human, avian) to AGI. The study will take place at eight targeted freshwater and marine beach sites in British Columbia, Manitoba, and Ontario. The qualitative research will consist of focus groups to determine beachgoer risk perceptions and behaviours toward recreational water quality and key informant interviews with stakeholders to provide additional socio-political insights and context.

The long-term goal of this study is to reduce the burden of RWI in Canada, contributing to improved public health. The study will be led by an experienced, diverse, and multi-disciplinary research team, including engagement with public health and environmental authorities. Activities will be guided by a stakeholder steering group consisting of key knowledge-users (KUs). This integrated KT approach will help to ensure that the results are relevant and useful to KUs, facilitating their direct uptake to influence recreational water quality policies and practice.

Inclusion Criteria:

• Ability to provide informed consent for the study and complete the surveys in English or French
• Home address in Canada or the U.S.
• Must not have participated in the study in the past 21 days

Exclusion Criteria:

• Not a Canadian or U.S. resident.

Beachgoing households and individuals present at one of the targeted study beach sites during the recruitment period.

Anonymized data will be made publicly available following the study conclusion and publication of results.

Study protocol will be submitted for publication in 2024, and will contain the analysis plan. The final consent form and code will be shared with publication of the results later in the study timeframe (2027-2028).