Question - What is the leading cause for swimming pool-related outbreaks of diarrheal disease?
Answer - The cited article notes “The number of recreational water illness outbreaks reported annually has increased dramatically in recent years. Cryptosporidium, which can stay alive for days even in well-maintained pools, has become the leading cause of swimming pool-related outbreaks of diarrheal illness. In 2011 and 2012, public health officials from 32 states and Puerto Rico reported 90 recreational water–associated outbreaks. Among the outbreaks caused by infectious pathogens, 37 (54%) were caused by Cryptosporidium.” (https://www.cdc.gov/healthywater/swimming/medical-professionals/index.html; accessed May 2018)