Detection of Penaeid Rod-shaped DNA Virus (PRDV) in Wild-caught Shrimp and Other Crustaceans.

Penaeid acute viremia (PAV) caused by penaeid rod-shaped DNA virus (PRDV), has been damaging kuruma shrimp (Penaeus japonicus) culture in Japan. The detection of PRDV in wild-caught shrimp and other crustaceans was conducted by using 2-step PCR. Fifty-one out of 202 wild-caught shrimp spawners showed PRDV-positive (25.2%) by 2-step PCR. The filtrate of the heart homogenate of those infected or virus-carrying adult shrimp was confirmed to kill healthy kuruma shrimp by injection challenge. Eleven decapod crustacean species, which were caught inside and outside kuruma shrimp ponds where PAV occurred, were PRDV-positive by 2-step PCR. The virus was frequently detected in the shore crabHelice tridens. The kuruma shrimp that cohabited with those infected shore crabs died showing white spots inside of the carapace, from which the virus was detected. These results suggest that PRDV can be transmitted by both horizontal and vertical routes.