In all, 30 fish farms randomly selected in nine (9) regions (Western, Central, Ashanti, Bono-East, Bono, Ahafo, Northern, Upper East and North-East) across Ghana were included in this survey. Farm interviews were conducted to gather epidemiological information using a structured questionnaire.

Biological fish samples were screened for bacterial and viral agents and specific organs were preserved for histopathological analysis. While bacterial and viral analyses were performed at the University of Ghana, formalin-fixed samples were sent to NVI, Norway for further processing and histological analyses. The virology testing focused on the presence of two key pathogens; Infectious spleen and kidney necrosis virus (ISKNV) and tilapia lake virus (TiLV) using the multiplex conventional and real time qPCR protocols developed by the University of Ghana with financial and material support from NVI.

The laboratory analysis revealed a range of potential bacterial pathogens. Edwardsiella and Aeromonas were the major pathogens associated with catfish, the predominant species cultured in ponds. Neither Streptococcus spp. nor TiLV were detected in any of the samples analysed. Nevertheless, ISKNV-like organisms were detected in seven (7) farms, mainly in Ashanti and the three (3) farms in the Northern regions from catfish. This ISKNV-like virus seems to affect largely adult grow out fish. Most farmers however had no information or suspicion of ISKNV disease on their farms. It appears a new variant of ISKNV is circulating in ponds, which might be different from the ones detected in tilapia from caged cultures in Lake Volta.

The outcome from this study provides a holistic view of fish diseases affecting pond cultures in Ghana, which adds to the existing knowledge to improve on the fish health situation in the Ghanaian aquaculture sector.