Asia contributes more than 90% to the world’s aquaculture production. Like other farming systems, aquaculture is plagued
with disease problems resulting from its intensification and commercialization. This paper describes the various factors,
providing specific examples, which have contributed to the current disease problems faced by what is now the fastest growing
food-producing sector globally. These include increased globalization of trade and markets; the intensification of fish-farming
practices through the movement of broodstock, postlarvae, fry and fingerlings; the introduction of new species for aquaculture
development; the expansion of the ornamental fish trade; the enhancement of marine and coastal areas through the stocking of
aquatic animals raised in hatcheries; the unanticipated interactions between cultured and wild populations of aquatic animals;
poor or lack of effective biosecurity measures; slow awareness on emerging diseases; the misunderstanding and misuse of
specific pathogen free (SPF) stocks; climate change; other human-mediated movements of aquaculture commodities. Data on
the socio-economic impacts of aquatic animal diseases are also presented, including estimates of losses in production, direct and
indirect income and employment, market access or share of investment, and consumer confidence; food availability; industry
failures. Examples of costs of investment in aquatic animal health-related activities, including national strategies, research,
surveillance, control and other health management programmes are also provided. Finally, the strategies currently being
implemented in the Asian region to deal with transboundary diseases affecting the aquaculture sector are highlighted. These
include compliance with international codes, and development and implementation of regional guidelines and national aquatic
animal health strategies; new diagnostic and therapeutic techniques and new information technology; new biosecurity measures
including risk analysis, epidemiology, surveillance, reporting and planning for emergency response to epizootics; targeted