Field assessment of antibiotic use in fish farms in Southwestern Nigeria

Abstract

Antibiotic resistance is a global public health issue linked to antimicrobial use in food animals. However, little is known of antibiotic use in aquaculture in developing countries and its link to antibiotic resistance. This study investigated antibiotic use in 50 aquaculture farms in Southwestern Nigeria using a structured questionnaire. Twenty-seven (54%) farms used antibiotics (n = 24), antiparasitics (n = 2) or both (n = 1) as additive to feed or water. The most frequently used antibiotics were tetracycline (11 farms), beta-lactams and furazolidone (4 farms each), aminoglycosides and chloramphenicol (3 farms each), enrofloxacin (2 farms) and metronidazole (1 farm). Only 16 farmers knew the antibiotics used in their ponds and no farm had data on the quantity used. The drugs were sourced from veterinary (59%) and human medicine stores (15%), veterinary doctors (4%), or other fish farmers (4%); 19% did not answer this question. Many farmers (n = 15), among whom 11 held a technician diploma or a university degree, did not know of any risk entailed by the use of antibiotics in their ponds. Direct addition of antibiotics to pond water practiced in these farms can create local reservoirs of antibiotic resistance and is a risk to public health.