Disease Transmission Risks Among Fish Farmers and Aquaculture-Linked Wildlife: Occurrence of Shared Gut Pathogens in Ibadan, Nigeria

Background and Objective: Nigerian aquaculture, dominated by African catfish (Clarias gariepinus), faces recurrent bacterial disease outbreaks. The interface between cultured fish and wildlife creates complex epidemiological pathways, facilitating bidirectional pathogen transmission. This study investigated the prevalence of shared gut pathogens, particularly Vibrio and Pseudomonas species, in aquaculture-related wildlife and cultured fish, while assessing fish farmers’ awareness of disease transmission risks in Ibadan, Nigeria. Materials and Methods: A cross-sectional study was conducted involving 21 consenting fish farmers. Structured questionnaires assessed knowledge and practices related to disease transmission. Gut samples from cultured catfish (n = 8) and wildlife associated with aquaculture, including striated heron (Butorides striata, n = 1) and crabs (n = 7), were collected from two pond locations. Samples were analyzed using biochemical characterization methods. Data were summarized descriptively, and statistical comparisons of pathogen traits, such as mannitol fermentation, were performed using chi-square tests. The level of significance was taken as 5%. Results: Most farmers were male (85.7%), highly educated (95.2% tertiary), and experienced (71.4% with >10 years). Wildlife encounters were common (71.4%), predominantly involving reptiles and birds, yet only 47.6% of farmers were aware of shared pathogens, and 33.3% recognized zoonotic risks. Vibrio species were isolated from 94.1% of wildlife and 77.8% of fish samples. Pseudomonas species were detected in 62.5% of wildlife and 77.8% of fish samples, with significantly higher mannitol fermentation in fish isolates (77.8%) compared to wildlife (25.0%) (χ² = 7.35, p<0.05). Conclusion: These findings reveal critical vulnerabilities in Nigerian aquaculture, highlighting gaps in farmer knowledge and the prevalence of shared gut pathogens at the fish wildlife interface. Integrated One Health strategies, including farmer education, biosecurity enhancement, and wildlife management, are essential to mitigate disease risks and safeguard aquaculture productivity.