The production of cultured prawns is an increasingly important industry worldwide. Thailand is the world's largest producer, with exports worth about $2500 million. In the past decade, however, disease has emerged as the single most important factor threatening the economic sustainability of prawn farming throughout the world. The World Bank estimated that in 1994 disease wiped out 45% of world production - a loss of about $3800 million. The collapse of the wild prawn fishery in the Yellow Sea has also been connected with disease in the prawn farming industry.

In 1996 the World Aquaculture Society called for greater knowledge of the structure, biology and epidemiology of viruses affecting the prawn farming industry in Asia. Such knowledge would also be important in protecting the small Australian industry which, in 1995-6, is estimated to have lost about 15% of potential production (more than $5 million) through disease.

Most deaths in farmed prawns are caused by White Spot Baculovirus (WSBV) and Yellow Head Virus (YHV). Significant research on the two viruses has been conducted in Thailand and elsewhere in the region. However, control of the two diseases is still limited by inadequate knowledge of the biology of the viruses, the characteristics of their spread, and by the lack of sensitive in-field tests for quick and accurate diagnosis of the presence of the virus.