Stewardship Program Reduces Antimicrobial Resistance at Equine Hospital

International guidelines support the One Health approach and recommend antimicrobial stewardship programs in veterinary medicine. National data on antimicrobial-resistant (AMR) bacterial colonization rates in horses are limited. Researchers in the United Kingdom performed a clinical audit to evaluate the efficacy of an antimicrobial stewardship program in reducing AMR bacterial colonization rates in a veterinary teaching hospital.

AMR Surveillance at a Veterinary Hospital

In Autumn 2021, the researchers planned their active AMR surveillance in perinatology/reproduction and internal medicine units. The first audit cycle (A1) took place from January to July 2022. In fall of 2022, they reviewed findings and implemented biosecurity policies. The reaudit (A2) took place from January to July 2023 after the hospital applied the biosecurity policies.

The study included 328 hospitalized horses (foals and adults). The researchers tested nasal and rectal swabs collected at admission/birth and discharge/euthanasia/death for methicillin-resistant Staphylococci (MRS), third-generation cephalosporins-resistant Gram-negative bacteria, and carbapenem-resistant Gram-negative bacteria. Fisher’s exact test and Mann-Whitney U test evaluated differences in AMR bacterial colonization rates, antimicrobial use, and hospitalization length between A1 and A2.

Study Findings

In A2, there was a significant reduction in overall AMR bacterial colonization rates (foals: OR = 0.27, 95% CI 0-0.87, p = 0.03; adults: OR = 0.39, 95% CI 0-0.77, p = 0.01), MRS colonization rates (foals: OR = 0.30, 95% CI 0-0.57, p < 0.001; adults OR = 0.42, 95% CI 0-0.83, p = 0.01), third-generation cephalosporins-resistant Gram-negative bacteria colonization rates (adults: OR = 0.47, 95% CI 0-0.89, p = 0.02; total: OR = 0.53, 95% CI 0-0.87, p = 0.01), and carbapenem-resistant Gram-negative bacteria colonization rates (foals: OR = 0.26, 95% CI 0-0.90, p = 0.03; total: OR = 0.24, 95% CI 0-0.78, p = 0.02). Highest priority critically important antimicrobial use decreased (foals: OR = 0.17, 95% CI 0-0.41, p < 0.001; total: OR = 0.20, 95% CI 0-0.43, p < 0.001), as did antibiotic treatment duration (foals: A1 7.75 ± 11.5, A2 3.70 ± 4.63 days, p < 0.001; adults: A1 3.70 ± 4.63, A2 0.74 ± 2.27 days, p = 0.04) and hospitalization length (foals ≤ 30 days old: A1 18.1 ± 18.9, A2 9.77 ± 7.01 days, p = 0.05; total: A1 16.0 ± 15.1, A2 12.6 ± 11.4 days, p = 0.03).

Bottom Line

This clinical audit confirmed the efficacy of the implemented antimicrobial stewardship program and supported its adoption in comparable veterinary settings.

https://beva.onlinelibrary.wiley.com/doi/10.1002/evj.70171

Related Reading

• Disease Du Jour: Antimicrobial Stewardship in Equine Practice
• Merging Equine Clinical Practice and Antimicrobial Stewardship
• Preventing Incisional Infections Following Colic Surgery

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