First description of Siberian sturgeon herpesvirus-induced mortality in Russian sturgeon (Acipenser gueldenstaedtii) and in Siberian sturgeon (Acipenser baerii) in Hungary: An emerging pathogen in aquaculture

Acipenserid species play an important role in aquaculture. Emerging viral diseases can cause high mortality on farms. During our investigations, Siberian sturgeon herpesvirus (SbSHV) was detected on a fish farm in Hungary rearing Russian sturgeon (Acipenser gueldenstaedtii) and Siberian sturgeon (Acipenser baerii). Herpesvirus infection may result in mortality rates up to 100% in young animals; on the other hand, adults usually suffer much less mortality. The affected fingerlings initially showed neurological symptoms and lost their appetite. Opaque deposits and haemorrhages were observed on the skin. After necropsy, samples were taken for virological and bacteriological investigation. A broad-spectrum PCR, developed for the detection of acipenserid and ictalurid herpesviruses (genus Ictavirus), was applied. The sequence analysis of the detected PCR fragment showed high identity to a previously described SbSHV strain originating from Russia. There is currently neither a cure nor an effective vaccine available on the market against this disease. Therefore, prevention and strict biosecurity protocols are the most important ways to keep the animals healthy.