Diarrhea and Swimming Still Don’t Mix

Healthy and Safe Swimming Week 2026 highlights the importance of preventing swimming-related illnesses, especially diarrhea caused by Cryptosporidium contamination in pools and aquatic venues. Environmental health practitioners play a key role in promoting safe swimming practices and supporting the use of the Model Aquatic Health Code (MAHC) from the Centers for Disease Control and Prevention. The MAHC provides science-based guidance for pool design, operation, and response procedures. Because Cryptosporidium can survive for days in properly chlorinated water, diarrheal incidents require immediate action, including hyperchlorination or supplemental disinfection methods. This column emphasizes that swimmers with diarrhea should avoid pools until 2 weeks after symptoms end. It also encourages aquatic staff and environmental public health professionals to remain vigilant in preventing contamination and educating communities about healthy and safe swimming behaviors.