Midcrop mortality syndrome has caused significant losses in Queensland and New South Wales prawn farms. Estimated losses over the period of 1994-98 are $44 million (CRC Project A1.4). Two viruses are thought to be involved, (LOV/GAV) and (SMV). We have focused on detecting and controlling SMV. A survey of 909 faecal samples from spawners correlated SMV PCR-positive results with a decrease in productivity. Spawners with PCR-positive faecal samples produced PLs with a 23% reduced survival compared to PCR-negative spawners. A similar negative relationship between PCR-positive spawners and the survival of progeny has been shown with white spot syndrome virus (WSSV) in Asia. We have already developed a robust PCR for use with faecal samples. We propose to refine the technique using ELOSA, and to produce a non-infectious positive control which will make it suitable for non-specialist laboratories and automation. Screening at the hatchery provides maximal downstream effect on controlling disease in the industry. There is a need to develop time and cost-effective screening tools for SMV to reduce the mortality caused by this virus. This application addresses that need.

Furthermore, SMV has been listed by OIE (Office International des Epizooties, 2000) as an "other significant disease", so Australia has reporting obligations as a signatory to the regulations of the World Trade Organisation. Development of a diagnostic kit for SMV will make it easier for more laboratories to test for SMV and therefore help Australia meet these obligations.