ABSTRACT
In 1978, a major outbreak of viral gastroenteritis in New South Wales, Australia resulted in the stringent requirement that all oysters sold in that state is depurated. In that Australia has always been New Zealand's largest export market for farmed oysters, this gave the initial impetus for a series of studies on the effectiveness of depuration of Pacific oysters grown under New Zealand conditions. Parameters for the successful depuration of fecal coliforms from Pacific oysters have been determined. Although the depuration of fecal coliforms is assumed to correlate with the depuration of other Enterobacteria, the same cannot be said of marine vibrios, specifically Vibrioparahaemolyticus. Virus particles are rapidly accumulated by Pacific oysters although the rate and degree of accumulation varies from oyster to oyster. Although viruses are initially attached to the mucus in the digestive tract, some are absorbed intracellularly into epithelial cells of the midgut.
