Enterovirus and Bacterial Evaluation of Mississippi Oysters

The numbers of enteric viruses and fecal coliform bacteria in oysters and water samples collected along the Mississippi Gulf coast during 1979 were determined. Ten viral isolates, representing members of the poliovirus group, were identified from an approved oyster harvesting site. The number of virus isolations increased to 51 when oysters were collected from a prohibited harvesting location. The majority of isolates were identified as poliovirus type 1 or 2, coxsackievirus B3 and B4, and echovirus type 24. Fecal coliforms in water samples collected at approved and prohibited locations confirmed the classification assigned to each area by the Mississippi State Board of Health. The numbers of fecal coliforms in oyster samples collected at the identical sites did not reflect the levels observed in water samples. There was no positive correlation between indicator bacteria in the water column and the number of viruses in the shellfish examined. These results imply that viral analyses of shellfish may be needed as an adjunct to bacteriological analyses so that shellfish safety is verified