Syncytial Hepatitis of Tilapia (SHT) is a newly described viral disease reported from Ecuador, Israel, Colombia and several other countries where tilapia farming is present.
The most consistently described target organs are the liver and gastrointestinal tract, although there are some reports of lesions within the central nervous system.
The presence of a novel virus with close affinity to the family Orthomyxoviridae has been demonstrated within hepatocytes of affected fish.
Histopathological lesions include necrotizing hepatitis with distinctive hepatocellular syncytial giant cell formation, dissociation of hepatocytes often with accumulation of lipoprotein, a predominantly lymphocytic inflammatory infiltration.
In the gastrointestinal tract, necrosis of gastric glandular epithelium and intestinal enterocytes can be observed together with protein casts, as can loss of pancreatic acini.
- Del-Pozo, J., Mishra, N., Kabuusu, R., Cheetham, S., Eldar, A., Bacharach, E., … & Ferguson, H. W. (2017). Syncytial hepatitis of tilapia (Oreochromis niloticus L.) is associated with orthomyxovirus-like virions in hepatocytes. Veterinary pathology, 54(1), 164-170.
- Ferguson, H. W., Kabuusu, R., Beltran, S., Reyes, E., Lince, J. A., & Del Pozo, J. (2014). Syncytial hepatitis of farmed tilapia, Oreochromis niloticus (L.): a case report. J Fish Dis, 37(6), 583-589.