Public health considerations associated with molluscan aquaculture systems: Human viruses.

The documentation of several recent outbreaks of human virus diseases associated with the consumption of shellfish has reiterated the threat posed by these agents to the shellfish industry. This article reviews pertinent outbreaks, identifies principal viral agents involved, and delineates systems which may be at greatest risk. The results of two recent laboratory studies which sought to define environmental factors that contribute to virus accumulation by shellfish are also discussed.

Modified Procedure for Extraction of Poliovirus from Naturally-Infected Oysters Using Cat-Floc and Beef Extract.

Methods for recovery of poliovirus type 1 (LSc2ab) from naturally-infected oysters ( Crassostrea gigas ) were examined. Extraction procedures analyzed included glycine-saline and polyelectrolyte (Cat-Floc) methods followed by concentration using modifications of an acid precipitation technique, Direct viral assay of shellfish homogenates, when compared to virus recovery following extraction, indicated that substantially fewer viruses were detected in initial homogenates. These data appeared to support the contention that input values based on homogenate assay were inappropriate in determining recovery efficiencies with naturally-infected shellfish.

Isolation of Naturally Occurring Enteroviruses from a Variety of Shellfish Species Residing in Long Island and New Jersey Marine Embayments.

Shellfish ( Crassostrea virginica and Mercenaria mercenaria ) and shellfish-raising waters from a variety of Long Island and New Jersey marine embayments were examined for the presence of human enteroviruses. Little difference in virological quality was noted between areas designated as being open or closed to shellfishing. Viral isolations could not be correlated with coliform counts from identical samples, indicating the need to re-evaluate the use of bacterial standards as indices of the overall sanitary quality of water and shellfish.