Modified procedure for the recovery of naturally accumulated poliovirus from oysters.

Methods were compared for their ability to recover poliovirus from oysters (Crassostrea gigas) which had been allowed to accumulate virus via normal filtration activities. Clarification procedures included glycine-NaCl and polyelectrolyte extraction methods followed by a variety of acid precipitation concentration methods. Polyelectrolyte flocculation followed by a beef extract-supplemented acid precipitation carried out at pH 3.5 yielded the most efficient recoveries. Direct assay of homogenates was found to be an unreliable method for determining the initial virus concentration in "naturally infected" oysters.

Survey of human virus occurrence in wastewater-recharged groundwater on Long Island.

Treated wastewater effluents and groundwater observation wells from three sewage recharge installations located on Long Island were assayed on a monthly basis for indigenous human enteroviruses and coliform bacteria for a period of 1 year. Viruses were detected in groundwater at sites where recharge basins were located less than 35 feet (ca. 10.6 m) above the aquifer. Results from one of the sites indicated the horizontal transfer of viable viruses through the groundwater aquifer.