Surveillance of common pathogens in penaeid shrimp cultured in Mekong delta

Abstract

White spot syndrome virus (WSSV) and Enterocytozoon hepatopenaei (EHP) are two serious pathogens affecting shrimp farms in the Mekong Delta region. This study aims to provide updated information on the distribution of common pathogens in three main shrimp production systems. As the region has the largest shrimp farming area, we conducted a study and survey on common pathogens infected in penaeid shrimp, specifically shrimp cultured in three provinces: Soc Trang, Bac Lieu, and Ca Mau—all of which are key shrimp farming provinces in the Mekong Delta. We used the PCR method to assess WSSV and EHP infection rates. For WSSV, DNA was extracted from the gills and amplified using nested PCR, which produced a product of approximately 570 bp. Of the 32 shrimp samples tested, 8 samples were found to be positive, with infection rates of WSSV in Soc Trang, Bac Lieu, and Ca Mau being 16.7%, 28.6%, and 25.0%, respectively. For EHP, DNA was extracted from the hepatopancreas and amplified using PCR, which produced a product of approximately 148 bp. Of the 32 P. vannamei and P. monodon samples tested, 7 samples were found to be positive, with overall infection rates of EHP in Bac Lieu and Ca Mau being 28.6% and 25.0%, and notably, no samples from Soc Trang were positive for EHP (0.0%). The obtained results confirm the presence of two common pathogens in three main shrimp farming systems in the Mekong delta, which raises the need to provide the appropriate method to control the diseases.