Aquamedicine Use for Disease Treatment in Pond-Based Commercial Tilapia Farms in Bangladesh

Abstract

This study addresses the limited information on aquamedicine use, including antimicrobial use (AMU), in commercial tilapia farms in Bangladesh. A retrospective cross-sectional survey was conducted in November 2022 in the Mymensingh district, a major tilapia production hub. Nearly half of the farms (46.6%) experienced fish mortality during the last production cycle, and 75.0% of farmers did not seek professional assistance during disease outbreaks. Among those who did, 68.0% relied on chemical or drug suppliers for guidance rather than veterinary experts. Biosecurity practices were inadequate, with 98.3% not implementing four basic monitored measures: disinfection of vehicles, footwear, hands, and equipment. Awareness of AMU risks among respondents was low, with 56.0% unaware of its negative impacts and 88.8% unfamiliar with antimicrobial resistance (AMR). Farms with polyculture systems or fish showing clinical signs or mortality were more likely to use treatment products (p<0.01). Treatment use varied significantly across different upazilas (p<0.001), suggesting location-specific differences in disease management. Antibiotic use was low, with only 15.5% of farms reporting antibiotic treatments, primarily oxytetracycline hydrochloride (23.8%), enrofloxacin (19.0%), and erythromycin–sulphadiazine–trimethoprim (19.0%). However, other chemicals with antimicrobial properties, such as disinfectants, were more commonly applied, reported by 39.7% of farms for disease management. Imprudent use of disinfectants and aquamedicines may pose One Health risks, including disruption of pond microbial ecosystems, AMR development, chemical residues, and occupational hazards. In-depth qualitative studies are needed to further understand and optimize aquamedicine use practices and determine how tilapia farmers may benefit from improved biosecurity, training, and veterinary access.