Prospective epidemiological study on the morbidity of bathers exposed to marine bathing waters. Sanchez Nazario, Elia Enid. University of Puerto Rico, Rio Piedras (Puerto Rico), ProQuest Dissertations Publishing, 2006. 3251244.

ABSTRACT

Microbial quality of beach water is of great concern to protect swimmer's health. Sewage effluents, river basins and storm water runoff are sources of fecal bacteria in these coastal waters. However, no study has been performed to quantify the risk of morbidity in beach bathers exposed to fecal bacteria in waters from the Caribbean island of Puerto Rico. The objectives of this epidemiological study were: to quantify the prevalence of gastrointestinal, respiratory and skin symptoms in swimmers from beaches in Puerto Rico, to determine microbial indicators concentrations in water and beach sand to help in the development of new microbial standards to protect swimmers health, and to calculate the risk of illness in swimmers from 3 public beaches. The epidemiological study indicated an increased risk of respiratory and skin symptoms in swimmers when compared to non-swimmers. A risk of gastrointestinal symptoms in swimmers when compared to non-swimmers was found, but this difference was not statistically significant. Survival experiments of E. coli in water and sand showed high survival rates of this indicator, meaning that its presence in the marine environment does not necessarily mean recent fecal contamination. A high decay rate of thermotolerant coliforms as compared to total coliforms and Enteroeocci in sand may mean that they are better indicators of fecal pollution in water. Illness rates by beach showed a higher prevalence and risk in Carolina Beach when compared to Luquillo and Isla Verde beaches and this prevalence was related to indicator density in water. In the continuous logistic regression of all beaches, an increase in coliphages in water was significantly related to an increase in the risk of gastrointestinal, skin, ear and respiratory illness in swimmers. Currently recommended recreational water quality standards are not protecting swimmer's health in Puerto Rico because an increase in these current indicators was not related to an increase in illness among swimmers. The use of other indicators such as coliphages may better protect swimmer's health at Puerto Rico beaches.