Largest-ever wild swimming trial challenges WHO move to drop E. coli monitoring

The largest randomised trial on wild swimming health risks, involving 2,368 participants in Hungary, found E. coli exposure was the variable most clearly tied to gastrointestinal illness, while enterococci showed no such link. The findings raise questions about the WHO's decision to drop E. coli as a recommended freshwater pollution indicator, potentially removing the most predictive marker for bather illness.