Swimming is the second most popular exercise activity in the United States, with over 400 million annual visits to recreational swimming venues such as pools and hot tubs and fresh and marine waters. Considering the massive exposure of the population to recreational water, what factors are currently impacting the quality of the water that they swim in? Enteric pathogens such as Giardia and Cryptosporidium can be found in most surface water in the United States. Other pathogens such as E. coli O157:H7, Shigella, and the Norwalk-like viruses have also been documented as recreational water illnesses (RWI’s) and many of these pathogens are environmentally stable, have low infectious doses, and may be shed for weeks after the cessation of diarrhea. The high incidence of diarrhea in the United States (>1 diarrheal episode/person/year), high bather loads, and heavy use by diapered and toddler-aged children make the shared water/communal bathing experience an ideal venue for spreading and amplifying community illness.

There has been a significant increase in the number of recreational water outbreaks over the past decade. Surveillance data from pool inspections illustrates the need for stronger compliance with existing pool regulations. These data and lessons learned from recent RWI outbreaks illustrate the urgent need for development of a broad based prevention plan for preventing the spread of RWI’s.