Healthy swimming expert Michael Beach warns about the superbug Crypto that causes the most common recreational water illness and suggests anyone with diarrhea should stay out of the water. The video explains that though we use chlorine to kill germs and protect our health, Crypto can survive for days in chlorinated water. Comments on this video are allowed in accordance with our comment policy: http://www.cdc.gov/SocialMedia/Tools/CommentPolicy.html This video can also be viewed at http://www.cdc.gov/cdctv/