First incidence of clinical signs of nodavirus infection in sea bream, Sparus auratus L

Abstract

The causal agent of viral encephalopathy and retinopathy in fish is an RNA virus known as nodavirus, a member of the Nodaviridae family. According to published data, sea bream (Sparus aurata L.) that are infected with the virus show no clinical signs and are considered an asymptomatic carrier. In this paper we report for the first time a clinical case of nodavirus in commercially reared sea bream. Fish with clinical signs underwent necropsy and routine microbiological, parasitological, and histopathological examination. The virus was detected by RT-PCR and isolated in SSN-1 cell cultures. The results described in this study demonstrate the presence of a nodavirus agent that can infect sea bream in sea water, causing a disease similar to that observed in marine sea bass but with lower mortality and milder neurological signs. Histopathological lesions were also similar to those observed in sea bass infected with nodavirus.