Canadian Beach Cohort Study

NCT06413485 | Active Not Recruiting

• 1 other identifier: PJT-192023
• Study Type: observational
• Target: 5,000
• Locations: 1 country
• Sites: 5

Brief Summary

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.

Conditions

Water-Related Diseases; Gastrointestinal Diseases

Keywords

Epidemiology; Beach water; Water quality; Fecal pollution; Cohort study; Mixed methods; Environmental health

Outcome Measures

Primary Outcomes (1)

• Acutre gastrointestinal illness (AGI)

  Self-reported AGI in the 7-day period following beach water contact. Defined as one or more of: (a) diarrhea (≥3 loose stools in 24 hrs); (b) vomiting; (c) nausea with stomach cramps; or (d) nausea or stomach cramps that interfere with regular daily activities (e.g., missed work or school).

  Within 7 days of beach visit/water contact

Secondary Outcomes (4)

• Acute respiratory illness

  Within 7 days of beach visit/water contact

• Skin infection

  Within 7 days of beach visit/water contact

• Ear infection or earache

  Within 7 days of beach visit/water contact

• Eye infection or irritation

  Within 7 days of beach visit/water contact

Study Arms (1)

Beachgoers

Beachgoing families and households to one or more Canadian beaches during the summers of 2023 to 2026.

Behavioral: Level of recreational water contact activities

Interventions

Level of recreational water contact activities BEHAVIORAL

We will examine a graded classification of this exposure based on individuals' minimum level of water contact: 1) no water contact; 2) minimal contact; 3) body immersion; 4) swallowed water. Minimal contact is defined as water contact that does not result in body immersion (e.g., wading below one's waist, boating, fishing). Body immersion is defined as entering the water above one's waist (e.g., swimming, surfing, snorkelling), and swallowing water as ingestion of any amount of water.

Also known as: Sand contact at beaches

Beachgoers

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

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

You may qualify if:

• 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

You may not qualify if:

• Not a Canadian or U.S. resident.

Sponsors & Collaborators

• Toronto Public Health: collaborator
• Public Health Agency of Canada (PHAC): collaborator
• Toronto Metropolitan University: lead
• University of Waterloo: collaborator
• University of Guelph: collaborator
• Health Canada: collaborator
• Vancouver Coastal Health: collaborator
• Government of Manitoba: collaborator
• Niagara Region Public Health: collaborator
• McMaster University: collaborator
• Halifax Regional Municipality: collaborator

Study Sites (5)

English Bay Beach and Kitsilano Beach

Vancouver, British Columbia, Canada

Location

Grand Beach

Winnipeg, Manitoba, Canada

Location

Birch Cove Beach

Halifax, Nova Scotia, Canada

Location

Bay Beach and Nickel Beach

Fort Erie, Ontario, Canada

Location

Sunnyside and Marie Curtis Park East beaches

Toronto, Ontario, Canada

Location

MeSH Terms

Conditions

Waterborne Diseases; Gastrointestinal Diseases

Condition Hierarchy (Ancestors)

Infections; Digestive System Diseases

Study Officials

• Ian Young

  School of Occupational and Public Health, Toronto Metropolitan University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: May 9, 2024
• First Posted: May 14, 2024
• Study Start: June 16, 2023
• Primary Completion (Estimated): September 15, 2026
• Study Completion (Estimated): March 31, 2029
• Last Updated: September 9, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: 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).

Locations

CA (5)