Methods for the concentration and detection of human enteric viruses in shellfish: a review

Shellfish, including oysters, mussels, and clams, are filter feeding bivalve mollusks and can accumulate human pathogens at levels higher than those in their surrounding waters. Outbreaks of shellfish-borne enteric viral diseases have been reported worldwide. To determine the public health safety of shellfish, methods are available for the direct detection of human enteric viruses in shellfish tissues. Potential problems with these methods include (i) toxicity of the final sample to cell cultures used for viral assay, and (ii) a large sample volume that cannot be conveniently assayed. To overcome these problems, several methods for the concentration and detection of enteric viruses in shellfish tissues have been developed and utilized. A review of these methods indicates that none of them is universally accepted because no single method is equally effective for shellfish obtained from different geographical locations and under all conditions. It is suggested, therefore, that a proposed method should first be tested under experimental conditions, utilizing virus-spiked shellfish, before using it under field conditions.