The aim of the programme is to develop specific tools for diagnosing herpes-like virus infections in bivalves and to validate these reagents by using them in different European laboratories involved in shellfish epidemiological surveys. This will done using techniques developed by the partners to characterise viruses by studying their genomes and immunologically reactive proteins, to cultivate oyster cells and vertebrate cell lines and to perform epidemiological surveys among bivalves. The programme objectives are: 1 - Obtaining the complete oyster herpes-like virus DNA sequence with determination of the genome structure. 2 - Comparing oyster herpes-like viruses with other viruses belonging to the Helpesviridae family on the basis of sequence data and genome structure. 3 - Developing molecular tools for oyster herpes-like virus detection using the complete virus DNA sequence data. 4 - Developing immunological tools for oyster herpes-like virus detection. 5 - Developing cellular tools for oyster herpes-like virus detection using oyster primary cell cultures and vertebrate cell lines. 6 - Application of developed diagnostic tools for herpes-like virus detection in oyster samples from different geographical locations.