Coliphages as indicators of enteric viruses in shellfish and shellfish raising estuarine waters

Abstract

The practicality of a coliphage indicator system for human enterovirus in polluted waters was studied. Parallel examinations of sewage effluents, shellfish and shellfish growing waters for coliphage and enteric virus indicated a wide dissemination of coliphage throughout the estuary, generally occurring in the absence of detectable enteric virus activity. A majority of the enteric virus isolations were observed in samples yielding no coliphage activity. Under controlled conditions, oysters were observed to accumulate more coliphage than enteric virus. Replication of coliphage in the estuary during the summer months was shown to occur when proper host cell was present. Two major coliphage types were observed in field samples based on their reactivity with different Escherichia coli strains. A shift in dominant coliphage type was seen to occur during the study. Survival times of coliphage and enteric virus in estuary waters along with retention values in oysters were shown to be similar with a slight advantage shown by coliphage. Inability to correlate accurately coliphage and enteric virus occurrence in field samples along with the potential for the presence of more than one dominant coliphage type indicated the serious shortcomings of the coliphage indicator system as a method of enteric virus detection, leaving its overall use in the polluted environment subject to grave doubt.