Detection and characterization of white spot syndrome virus in imported blue crayfish (Procambarus alleni) from the ornamental trade

Abstract

White spot disease, caused by the white spot syndrome virus (WSSV), is a notifiable disease of decapod crustaceans, and international trade poses risks for its spread. Here, we describe an asymptomatic mortality event in blue crayfish (Procambarus alleni) imported from Thailand to the USA through the ornamental trade. WSSV was confirmed with histology, in situ hybridization, and real-time PCR. Next-generation sequencing and phylogenetic analysis revealed that this WSSV isolate was genetically distinct from the USA isolate and clustered with Asian isolates. This report exemplifies the poorly documented risk of disease spread through the ornamental trade.