Quantitative and qualitative analysis of antimicrobial usage and biosecurity on broiler and Sonali farms in Bangladesh.

Antimicrobial use (AMU) is a major contributing factor to the rising threat of antimicrobial resistance (AMR) in human and animals. To control AMR, indiscriminate antibiotic use needs to be restricted, preventive measures such as biosecurity must be prioritized and proper action plans must be implemented. This study aimed to quantify and associate AMU and biosecurity status of broiler and Sonali farms in Bangladesh. Data on all antimicrobial treatments administered during a batch production cycle and antimicrobials purchased over a year were collected from 94 conventional broiler and 51 Sonali (cross-breed) farms from the northern and southeast regions of Bangladesh. Flock-level AMU was quantified using Treatment Incidence (TI) per 100 days based on the Defined Daily Dose (TI) expressing the number of days per 100 animal-days at risk that the flock receives a standard dose of antimicrobials. The biosecurity status (external and internal) of these farms was assessed by means of the Biocheck.UGent scoring system and the correlation between biosecurity and TI were assessed by Pearson's correlation coefficients. Median flock TI was 60 and 58 for broilers and Sonali flocks, indicating that the birds were treated around 60% and 58% of their lifetime with an antimicrobial dose, respectively. Minimum and maximum values of TI ranged from 18 -188 and 31-212 in broilers and Sonali, respectively. Fluoroquinolones, sulfonamides, tetracyclines and aminopenicillins were the most frequently used antimicrobial classes. The mean external and internal biosecurity scores were 39% and 61% for broilers and 44% and 61% for Sonali, respectively. There was a statistically significant difference in the external biosecurity score in broiler farms in the two regions (p ≤ 0.001), whereas, the internal biosecurity score was borderline not statistically significantly different (p = 0.065). The biosecurity score was negatively correlated with AMU in broiler and sonali farms both for external (R =-0.38; -0.36) and internal biosecurity (R =-0.33; -0.32), respectively. As most of the farmers treated their birds with antimicrobials for a very large part of the production, it could be concluded that there is a high overuse of antimicrobials both in broiler and Sonali poultry production in Bangladesh. This study also highlighted a low level of farm biosecurity practices. Overuse of antimicrobials and low level of biosecurity practice may be due to a lack of knowledge, ignorance, avoid loss and/or lack of monitoring by governmental agencies. Therefore, urgent action is required to increase awareness and biosecurity levels and to reduce AMU in these production systems.