EPIZOOTIOLOGY, DISTRIBUTION AND THE IMPACT ON INTERNATIONAL-TRADE OF 2 PENAEID SHRIMP VIRUSES IN THE AMERICA

Marine penaeid shrimp are affected by appproximately twenty viruses, t he majority of which were discovered as a result of their negative eff ects on aquaculture. In the Americas, infectious hypodermal and haemat opoietic necrosis (IHHN) virus and Taura syndrome (TS) virus have had a significant negative impact on aquaculture industries and, in one in stance, on a commercial fishery. Both viruses have become widely distr ibuted as a consequence of the movement of host stocks for aquaculture . IHHN virus (IHHNV) causes catastrophic losses in cultured and wild P enaeus stylirostris. In marked contrast, P. vannamei is relatively res istant to IHHN but infection results, nonetheless, in poor culture per formance. TS virus (TSV) is the 'mirror image' of IHHNV in its effect on P. stylirostris and P. vannamei TSV causes catastrophic losses in P . vannamei whereas P. stylirostris is highly resistant to TS. In the l ess than three years since the discovery of TSV in Ecuador in 1992, th e virus has spread rapidly and caused massive production losses in mos t shrimp-growing countries in the Americas.