The Sixteenth Conference of the International Society for Environmental Epidemiology (ISEE): Abstracts
Swimming is the second most popular exercise activity in the United States with almost 400 million annual visits. The public health consequences of this exposure are that transmission of ear, eye, respiratory, and diarrheal illness are repeatedly linked by epidemiologic studies with use of fresh and marine water use. The contamination of recreational water with waste from humans and animals combined with pathogens that are relatively long-lived in the environment and have low infectious doses serves to make recreational water an ideal vehicle for disease transmission.
Surveillance for outbreaks associated with drinking water and recreational water has been ongoing since 1920. The Centers for Disease Control and Prevention, the Environmental Protection Agency, and the Council of State and Territorial Epidemiologists have maintained a collaborative surveillance system for waterborne disease outbreaks (WBDOs) since 1971. State, territorial, and local public health agencies are responsible for detecting and investigating WBDOs and voluntarily agree to report these outbreaks to CDC. The National Waterborne-Disease Outbreak Surveillance System (WBDOSS) collects data regarding outbreaks associated with drinking water and recreational water.
Most outbreaks reported are of diarrheal illness. Over 100 outbreaks of diarrheal illness have occurred during the past decade (1989-1998) with 50% occurring in freshwater locations. Almost one third of the diarrheal illness outbreaks associated with freshwater use had no pathogen identified. Of those diarrheal outbreaks where pathogens were identified, the major ones were Shigella sonnei, E. coli O157:H7, Giardia intestinalis, Norovirus, and Cryptosporidium spp. Poor reporting of diarrheal illness to public health agencies makes it likely that the reporting system is insensitive and that the majority of outbreaks going undetected. The primary objective of collecting these outbreak data is ultimately to reduce the occurrence of WBDOs by characterizing the epidemiology of the outbreaks, identifying the etiologic agents, and determining the reasons for the occurrence. These efforts then provide the opportunity to develop public health prevention and control messages.