Burden of Recreational Water Illness Due to Exposure to Cyanobacteria and Their Toxins in Freshwater Beaches in Canada
NCT Number: NCT06579170
Status: ENROLLING_BY_INVITATION
Study Type: OBSERVATIONAL
Conditions: Gastroenteritis|Gastrointestinal Diseases|Eye Infections|Skin Infections|Respiratory Tract Infections|Blue Green Algae Poisoning
Interventions: BEHAVIORAL: Cyanobacteria exposure during water contact
Sponsor: Toronto Metropolitan University
Collaborators: Ontario Ministry of the Environment, Conservation and Parks|Manitoba Environment and Climate Change|Windsor-Essex County Health Unit|Canadian Veterinary Medical Association|Health Canada
Sex: ALL
Age: CHILD, ADULT, OLDER_ADULT
Enrollment: 2500
Study Design: Observational Model: |Time Perspective: p
Start Date: 2024-06-01
Completion Date: 2026-03-31
Locations: Grand Beach, Winnipeg, Manitoba, R0E 0T0, Canada|Shubenacadie Canal, Halifax, Nova Scotia, B2X 2W5, Canada|Kinsmen beach, Port Perry, Ontario, L9L 1R2, Canada|Colchester Beach, Windsor, Ontario, N0R 1G0, Canada

Summary:
Swimming and other recreational water activities at public beaches are increasingly popular leisure activities among Canadians. However, harmful algal blooms caused by blue-green algae (i.e., cyanobacteria) have also been increasing reported at Canadian public beaches in recent years. These algal blooms can cause various acute illnesses among recreational water users through ingestion, inhalation of aerosols, or skin contact with contaminated water. In addition, blue-green algae blooms and their toxins can cause illnesses in pets and wildlife. Currently, baseline data are lacking on the risk of recreational water illness from exposure to blue-green algae blooms in Canada. This study will identify the burden of recreational water illness among recreational water users at four targeted beach sites in Ontario, Manitoba and Nova Scotia, over a two-year period. A prospective cohort study design will be used. We will determine the risk of acquiring acute illness outcomes in recreational water users, as well as their pet dogs, that engage in different levels of water contact at beaches at risk of blue-green algae blooms. We will examine differences in illness risks by gender, age, and location. We will examine relationships between cyanobacterial cell counts, toxin levels, and environmental conditions with the risk of acute illness among participants. Overall, results will provide important data on the risk of recreational water illness from exposure to blue-green algae and their toxins in Canadian beach settings.

Primary Outcome Measures: Gastrointestinal illness, Gastrointestinal illness is 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 3 days of beach visit
Secondary Outcome Measures: Respiratory illness, Defined as: sore throat, runny or congested nose, difficulty breathing, or cough, Within 3 days of beach visit|Skin infections, Defined as: rash or itchy skin, Within 3 days of beach visit|Eye infections, Defined as: eye infection or irritation, Within 3 days of beach visit|Generalized symptoms, Defined as: headache, fever, fatigue, dizziness, loss of appetite, chills, muscle pain, or general pain, Within 3 days of beach visit
Other Outcome Measures: Illness severity, Medical consultations, hospital visits, medication use, and hospitalization, Within 3 days of beach visit