Persistence of viral pathogens and bacteriophages during sewage treatment: lack of correlation with indicator bacteria

The effects of different sewage treatments on the viral contamination in rivers which receive water from treatment plants without a final sand filtration step were investigated. They were all heavily contaminated with bacteriophages and human enteric viruses (detected by single step reverse transcription amplification followed by a nested polymerase chain reaction). Bacteriophages, but not faecal indicator organisms, were correlated with viral contamination.