First identification of rhabdoviruses coinfecting tilapia (Oreochromis niloticus) in central-western Gabon

Tilapia are susceptible to a number of viral diseases that have a severe economic impact in many countries. During a mass mortality event in lakes in central-western Gabon in 2019, the first rhabdoviruses infecting tilapia were identified. Two distinct and nearly complete viral genome sequences were obtained by combining whole-genome sequencing (WGS) and Sanger sequencing of amplicons. The two viruses, which we have named "tilapia rhabdovirus 1" (TiRV1) and "tilapia rhabdovirus 2" (TiRV2), were found coinfecting a single fish. These viruses are related to, but clearly distinct from, members of the subfamily Alpharhabdovirinae. The respective roles of TiRV1 and TiRV2 in the present disease outbreak remain to be clarified. Further studies are needed to evaluate whether these viruses pose a threat to the health of this fish species throughout the region.