Surveillance and confirmation of White Spot Disease in Cultured White Leg Shrimp (Litopenaeus vannamei) from Port Said and Damietta Governorates

Abstract

This study was done to detect the epidemiology of WSSV (white spot syndrome virus) and how to diagnose it by molecular tools. 200 cultured Litopenaus vannamei samples were collected seasonally and randomly from different localities in Egypt such as Damietta and Port Said governates. Infected shrimp exhibited white spot lesions on the carapace and all over the external surface. Some cases revealed a generalized pink body color and red coloration of appendages (telson). The total prevalence of white spot syndrome among collected shrimp was 11.5% and the seasonal prevalence was 0% ,0% ,6% and 40% in winter, spring, summer and autumn respectively. Molecular diagnosis by conventional PCR with primers specific for WSSV VP28 gave a predicted amplified product at 677 bp fragments by agarose gel electrophoresis. Confirmation of diagnosis was done by histopathological examination, which revealed nuclear basophilic inclusion bodies in the subcuticular cells and vacuolation, degeneration with disarrangement in the hepatopancreas of infected shrimp .