Aquaculture management practices associated with antimicrobial residues in Southwestern Nigeria

Aquaculture production has grown rapidly in Nigeria but with unbridled use of antibiotics which predisposes fish consumers to the risks of antimicrobial residues and resistance. A cross sectional survey of antimicrobial use in aquaculture and occurrence of their residues in African Catfish (Clarias gariepinus) samples from Southwestern states of Nigeria were carried out. The results showed that majority of the farmers lacked knowledge of drug residues in aquatic animals, and the food safety and public health implications on consumers. Frequently administered antibiotics include tetracyclines (27.5%), chloramphenicol (22.0%) and gentamicin (18.4%). About 84.7% of tested fish had residues with variable prevalence which were not statistically significant. Risk factor analysis indicated that fish farmers with tertiary and secondary education were more likely to produce fish that contained antimicrobial residues than those with primary education [odds ratio (OR) = 1.91, confidence interval (CI) = 1.24–5.99 and OR = 1.25, CI = 1.08–5.27, respectively] while fish from farms managed by men were about three times more likely to contain residues (OR = 3.25, 95% CI = 1.95–9.35) than those managed by women. Hence, most of the fish from Southwestern Nigeria were indiscriminately dosed with different antibiotics that predispose consumers to the risks of antimicrobial residues with food safety and antimicrobial resistance consequences. Implementation of good fishery management practices and farmers' education are advocated to reduce dependence on antimicrobials