Zoonotic bacteria and their exposure factors in aquaculture in Chirundu and Siavonga districts of Zambia.

This study aimed to identify bacterial pathogens with zoonotic potential found in fish in Chirundu and Siavonga districts of Zambia. Accordingly, a total of 63 fish and 59 water samples from three fish farms (ponds and cages) were aseptically collected and bacteria isolated from the skin, gills, liver, spleen and intestines of fish and from the water samples. Isolates were identified through standard bacteriological methods through culturing, morphological characteristics, Gram staining characteristics and a series of biochemical tests. The following well-known fish pathogens were identified with attendant prevalence of, Aeromonas 13.2%, Lactococcus/Streptococcus 4.2% and Staphylococcus 18.1%. Other bacteria with varying significance as fish pathogens were also identified including Acinetobacter 2.1%, Aequorivita 1.4%, Aerococcus 1.4%, Bacillus 2.1%, Bordetella 2.1%, Carnobacterium 10.4%, Citrobacter 3.5%, Clostridium 2.1%, Corynebacterium 1.4%, Dermatophilus 1.4%, Enterococcus 2.1%, Escherichia coli 0.7%, Flavobacterium 4.2%, Klebsiella 6.9%, Lactococcus 2.1%, Listeria 0.7%, Micrococcus 6.9%, Planococcus 1.4%, Proteus 1.4%, Pseudomonas 6.3%, Rhodococcus 1.4%, Shewanella 1.4%, Streptococcus 0.7% and Vagococcus 0.7%. Aeromonas, Bacillus, Clostridium, Escherichia coli, Klebsiella, Lactococcus, Listeria, Staphylococcus and Streptococcus were of zoonotic importance. The three farms had various production types from which the general exposure factors were identified following visual determination. All key determinants in the exposure pathway were categorized under demographical, biological, environmental and/or management factors. These were then processed individually before being combined into a final framework to inform the impact pathway using the spider web analysis to aggregate exposure factors. The current study provides baseline information for future reference and implementation of public health guidelines regarding fish disease and the health of consumers in the country.