This laboratory has previously described the development of a PCR method for the detection of small round structured viruses (SRSVs) in shellfish and the use of male-specific RNA bacteriophages as “viral” indicators to predict the occurrence and behaviour of such viruses in shellfish. We now describe the application of these procedures to monitor oyster harvesting areas, shellfish treatment processes and products sold to the consumer. Oysters are traditionally consumed raw and can be treated to enable them to meet the legislative end-product standard of <230 E coli/100g. Treatment options include purification (depuration) in tanks of clean seawater or relaying in clean seawater for a suitable period. These procedures are effective for enabling shellfish compliance with the existing bacterial end product standard but do not guarantee viral protection for the consumer. This study initially investigates the efficiency of these treatment processes for reducing viral contamination in sewage-contaminated oysters. Initial levels of viral pollution in oysters were found to be critical to the success of post-harvest treatment processes. Additionally, the success of depuration and relaying for virus removal was found to be dependent on the duration of the process and on factors affecting shellfish metabolic activity such as the water temperature. We demonstrate that by using male-specific RNA bacteriophage as an indicator of viral pollution combined with SRSV monitoring it is possible to derive management strategies for more effective control of the virological quality of oysters. Male-specific RNA bacteriophage monitoring of final products prior to sale to the consumer provided an effective quality control mechanism. We discuss the combined use of these new monitoring tools for more effective management of the virological quality of oysters sold to the consumer.

This content is only available as a PDF.
You do not currently have access to this content.