A Study of the Occurrence of Tilapia Lake Virus in Farmed Tilapia in Zambia

Abstract

Tilapia Lake Virus (TiLV) disease induces high mortalities in tilapia aquaculture and may result in substantial economic losses for the tilapia industry. Even with growing research about TiLV and the disease, there is still more to be learnt about the pathogenesis and the geographic distribution of the virus. Tilapia production is one of the largest aquaculture food industries worldwide, stretching from China to Colombia and Ghana. Zambia is the fourth largest tilapia producing country in Africa, preceded by Ghana, Uganda and Egypt in ascending order. Tilapia lake virus has been reported in 16 countries so far, with detections in Uganda and Egypt in 2017. Even with the presence of TiLV in surrounding countries, Zambia has not conducted a comprehensive testing of the virus nationally. In this study, we examined fish farms along the line of rail including Kabwe, Ndola, Kitwe, Kalulushi as well as Siavonga. We sampled a total of 197 fish from eight different locations. Materials collected were from the head kidney and the spleen from apparently healthy fish. The samples were transported in RNAlater, RNA was extracted in the laboratory and measurements of concentrations were done by Nanodrop. We performed real-time PCR on all samples for the detection of TiLV genome. We did not confirm the presence of TiLV in any of our samples.