Reduced antimicrobial use in weaned pigs through an intervention program supporting veterinarians' adherence to the clinical practice Streptococcus suis guideline.

Veterinary guidelines have been published in the Netherlands to promote antimicrobial stewardship. An evidence-based intervention program using Implementation Mapping and performance indicators was developed to enhance veterinarians' adherence to the veterinary guideline "Streptococcus suis in weaned pigs". The present study evaluates the effect of this eight-month intervention program in a multicenter, pragmatic, stepped-wedge cluster design trial. Of the 49 veterinarians that participated, 33 provided data from 125 S. suis problem farms. A baseline measurement (M0) before the intervention program, and two measurements during (M1) and partly after (M2) the intervention program were conducted. A significant reduction in farm-level antimicrobial use of 25% in M1 and 49% in M2 was achieved compared to M0. For the performance indicators at veterinarian level, a significant reduction (- 36%) was found for antimicrobial prescription in M2, a significant increase occurred in argumentation for 2nd choice antimicrobials (M2) and the usage of bacteriological examination (M1). Two other performance indicators (ratio of 1st to 2nd or 3rd choice antimicrobials and corticosteroids) did not change significantly. These results show how an evidence-based intervention program to foster adherence to an existing veterinary clinical practice guideline achieved a significant reduction in antimicrobial prescriptions by swine veterinarians.