Antimicrobial usage in broiler poultry farms in Zambia

Although Zambia and many other countries globally have very high rates of antimicrobial resistance, there is a surprisingly limited amount of quantitative data on antimicrobial use (AMU) to guide important control actions. Here, we used the VetCAb-ID [Veterinary Consumption of Antibiotics-International Documentation; ©Tierärztliche Hochschule (TiHo) Hannover, Germany] system to conduct a prospective longitudinal analysis of AMU in broiler poultry farms in the Lusaka district of Zambia to quantify the use by the treatment frequency (TF) metric. The overall TF was 7, and the median treatment frequency per day (TFpd) was 0.14. Of all flocks, 80% of them received treatment. Metaphylactic treatment was applied to all flocks at all farms. Overall, a total of nine antimicrobial classes were used, namely tetracyclines, aminoglycosides, aminopenicillins, diaminopyrimidines, fluoroquinolones, macrolides, phosphonic acid derivatives, quinolones, and sulphonamides. Tetracyclines were the antimicrobials most commonly used (62.7%), followed by sulphonamides (15.7%). Prophylactic use accounted for the majority (54.9%) of the total AMU in this study. Therapeutic uses of antimicrobials were primarily for digestive (21.14%) and respiratory (23.43%) problems of the chickens. Of all the treatments recorded, a greater proportion (87.8%) were underdosed, and 7.3% were overdosed. This study demonstrates the feasibility of farm-level monitoring of AMU data from Zambian poultry farms and provides the first quantitative trends of AMU in poultry farms in Zambia. Our findings of the widespread use of antimicrobials for prophylaxis, incorrect dosing patterns, and the relative usage of the highest-priority critically important antimicrobials in Zambian broiler poultry farms are suggestive of misuse. There is a need for continued education about the issue of antimicrobial resistance, application of antimicrobial stewardship, and the establishment of monitoring and benchmarking systems.