Assessing White Spot Syndrome Virus (WSSV) and Acute Hepatopancreatic Necrosis Disease (AHPND) concurrent with Vibrio spp. in various Penaeus monodon aquaculture farms at southwestern region of Bangladesh

This study was conducted to assess the prevalence of White Spot Syndrome Virus (WSSV) and Acute Hepatopancreatic Necrosis Disease (AHPND) in giant tiger shrimp ( Penaeus monodon Fabricius, 1798) aquaculture systems (extensive, improved-extensive, and semi-intensive) in the southwestern region of Bangladesh. This research employed real-time polymerase chain reaction (RT-PCR) to quantification cycle (C q ) values for identification of WSSV and AHPND in shrimp samples and Vibrio spp. was identified through biochemical tests on water and soil samples ( n = 72 for each) from different aquaculture systems. The results of the study indicated significant difference ( p < 0.05) in nitrate and ammonia levels across the various aquaculture systems, highlighting the critical need for rigorous water quality monitoring and management. Extensive aquaculture exhibited the highest prevalence of WSSV (40 %) and AHPND (33 %) positive samples, whereas semi-intensive aquaculture had the lowest prevalence, with 22 % WSSV-positive and 20 % AHPND-positive samples. Biochemical analysis identified three Vibrio spp. such as V. cholerae, V. parahaemolyticus, and V. vulnificus - with significantly higher concentrations in extensive aquaculture compared to semi-intensive. Notably, V. vulnificus was more abundant (0.9 × 10 3 cfu/ml) in the soil of extensive aquaculture, while it was less prevalent in water. In conclusion, this study highlighted that the risk of WSSV and AHPND was greater in extensive aquaculture due to inadequate management.