Aquaculture in Uganda is growing tremendously with the government promoting sustainable commercialization. However, this has come with expansion and intensification of production systems and increased live fish movement due to trade, leading to increased risk of disease outbreaks. In addition, Uganda’s human and infrastructural capacity in fish disease diagnosis and response is limited. Previous related research has focused parasites mainly in wild hosts with limited research on bacterial, viral and fungal diseases, their epidemiological factors, disease prevention and control. The need to build disease early warning systems, improve diagnosis and response in case of outbreaks, and strategies to reduce disease occurrence/emergence are now necessary. Multistakeholder engagement and collaborating using a One Health approach has been recognized globally as a best practice of disease control and prevention strategies that recognizes the interconnections among humans, animals, environment as well as the economic, cultural and physical factors that influence health. This study incorporated the One Health approach in fish health management taking into account the assessment of pathogens of bacterial pathogens of Public Health concern; ascertaining the epidemiology of transmission of these pathogens on farm and between farms; and drivers of disease emergence, recommendations for best fish health management practices and on farm biosecurity measures, and multistakeholder interventions to reduce fish disease emergence.
A cross sectional study was used to generate both qualitative and quantitative data. Two commonly farmed fish species, namely, Clarias gariepinus (catfish) and Oreochromis niloticus (Nile tilapia) were sampled from ponds, and cages from 79 fish farms in 9 sub counties in Wakiso district, Uganda. Over 500 fish samples were collected, and visibly lesioned fish examined and fish tissue including, the kidney, liver, spleen, gills, and brain were ascetically dissected from each fish. Physico-chemical water quality specifically temperature, dissolved oxygen, pH and conductivity were measured from each pond/cage/tank in-situ. In addition, a questionnaire was administered to the farmer or farm manager to collect information of the disease occurrence and how they manage disease at each fish farm. This was to assist in explaining the difference in the fish husbandry practices among fish farms where disease was witnessed vs fish farms where fish diseases were not found. Thus recommendable husbandry practices would be conclusively recommended to fish farmers and practices that predispose fish to diseases would be communicated and reformed.
Fish lesions included skin discoloration, hemorrhages, ulcerations and abscesses, exophthalmia, and granulomas in the internal organs. Two major pathogenic fish bacteria types were identified and included; Aeromonas species and Edwardsiella species. Some of the disease drivers identified during the study included, poor hygienic measures, Limited preventive measures of fish health management practices, lack of record keeping, lack of extension services; limited knowledge of fish behaviors and fish health, poor sources of fish seed, and self-medication. Fish farmers, feed producers, academia, government service providers will be convening in two weeks-time to be sensitized on the results from the study, and collectively design interventions to reduce the drivers of exposure to and or the spread of bacterial pathogens in aquaculture and improve fish productivity. This multistakeholder workshop will be the first of its kind to come together for this purpose. Results with this workshop will shared at the Africa Aquaculture Conference AAFRAQ 21 during the Aquatic Animal Health Session..