Tilapia Lake Virus (TiLV): What You Need to Know
Tilapia Lake Virus (TiLV) is a virus that poses a significant health threat worldwide to Nile tilapia, Oreochromis niloticus and hybrid tilapia (O. niloticus x O. aureus). TiLV is in the influenza virus family, Orthomyxoviridae. The World Organization for Animal Health (OIE) is reviewing TiLV to include on its finfish disease list because of the impact it has had on global tilapia production, and the high risk of the virus being moved by infected fish.
TiLV affects fingerling tilapia with reported death rates in affected populations as high as 90%. Older animals may have a lower mortality rate. Handling stress (i.e., moving fish between ponds) appears to be a significant risk factor for outbreaks. The virus survives in both fresh and brackish water. Direct fish to fish transmission is an important route of infection. There is no information on vertical transmission (parent to offspring).