BACTERIOPHAGES ARE A BETTER INDICATOR OF ILLNESS RATES THAN BACTERIA AMONGST USERS OF A WHITE WATER COURSE FED BY A LOWLAND RIVER

An examination was made of the risk factors for gastrointestinal illne ss (GI) and other symptoms among canoeists and rafters using an artifi cial white-water canoe slalom course fed by a lowland river. The inves tigation was made by carrying out cohort studies of users on several d ays throughout one year. On each day water samples were collected for the determination of Escherichia roll, enterococci (faecal streptococc i), F-specific RNA bacteriophage, sulphite reducing clostridia, cultur able enteroviruses and turbidity. Of 755 questionnaires distributed, 4 73 (63%) were returned. The relative risks of GI and other symptoms we re determined by logistic regression analyses. The variables associate d with an increased risk of GI-illness were swallowing water, unintent ional swimming in the course, eating and drinking before getting chang ed and the levels of F-specific RNA bacteriophages. Being a regular us er was associated with a decreased risk of GI-illness. This study demo nstrates the value of F-specific RNA bacteriophages as an index of ris k from recreational use of a fresh water environment. (C) 1997 IAWQ. P ublished by Elsevier Science Ltd.