BIOACCUMULATION AND DEPURATION OF ENTEROVIRUSES BY THE SOFT-SHELLED CLAM, MYA-ARENARIA

Low levels of feces-associated natural virus [poliovirus], simulating virus numbers estimated to exist in moderately polluted shellfish-growing waters, were used to evaluate the effectiveness of depuration as a virus depletion procedure in soft-shell clams. Depuration effectiveness depended on the numbers of virus bioaccumulated and whether virus was solids associated. Virus uptake was greatest when viruses were solids associated and pollution levels were equivalent or greater than those likely to be found in grossly polluted growing waters. Virtually all bioaccumulated feces-associated natural virus was deposited within the hepatopancreas or siphon tissues. Viruses usually were eliminated within a 24-48 h depuration period. Dependence upon depuration of clams to eliminate health hazards of virus etiology involved a risk factor not measurable in the study. The greatest reduction of health risks would come from the routine depuration of clams harvested from growing waters of good sanitary quality.