No abstract

Use of antimicrobials selects for antimicrobial resistance, and this poses a threat for both human and animal health. Although previous studies show that total antimicrobial use in Dutch companion animal clinics is relatively low and decreasing, the majority of antimicrobials prescribed are categorised as critically important for human medicine by the World Health Organization (WHO). Large differences in use between clinics are also observed. Identification of factors that influence the prescribing behaviour of veterinarians is needed to tailor future interventions aimed at promoting prudent use of antimicrobials in companion animals. The aim of this study was to explore factors influencing the antimicrobial prescribing behaviour of companion animal veterinarians in the Netherlands. Face-to-face, semi-structured interviews were used to interview 18 Dutch companion animal veterinarians. Interviews were held until theoretical data saturation was reached. An interview guide was used to structure the interviews, and ATLAS.ti 7.5 was used to manage and analyse the qualitative data. An iterative approach was applied to develop a conceptual model of factors that influence antimicrobial prescribing behaviour. The conceptual model shows four major categories of factors that influence the antimicrobial prescribing behaviour: veterinarian-related factors, patient-related (i.e. owner- and pet-related) factors, treatment-related factors (i.e. alternative treatment options and antimicrobial-related factors) and contextual factors (i.e. professional interactions, further diagnostics and environmental factors). All four major categories of influencing factors should be addressed to improve awareness on antimicrobial prescribing behaviour and to develop an antimicrobial stewardship programme for companion animal clinics.

BackgroundTo curb increasing resistance rates, responsible antimicrobial use (AMU) is needed, both in human and veterinary medicine. In human healthcare, antimicrobial stewardship programmes (ASPs) have been implemented worldwide to improve appropriate AMU. No ASPs have been developed for and implemented in companion animal clinics yet.ObjectivesThe objective of the present study was to implement and evaluate the effectiveness of an ASP in 44 Dutch companion animal clinics. The objectives of the ASP were to increase awareness on AMU, to decrease total AMU whenever possible and to shift AMU towards 1st choice antimicrobials, according to Dutch guidelines on veterinary AMU.MethodsThe study was designed as a prospective, stepped-wedge, intervention study, which was performed from March 2016 until March 2018. The multifaceted intervention was developed using previous qualitative and quantitative research on current prescribing behaviour in Dutch companion animal clinics. The number of Defined Daily Doses for Animal (DDDAs) per clinic (total, 1st, 2nd and 3rd choice AMU) was used to quantify systemic AMU. Monthly AMU data were described using a mixed effect time series model with auto-regression. The effect of the ASP was modelled using a step function and a change in the (linear) time trend.ResultsA statistically significant decrease of 15% (7%-22%) in total AMU, 15% (5%-24%) in 1st choice AMU and 26% (17%-34%) in 2nd choice AMU was attributed to participation in the ASP, on top of the already ongoing time trends. Use of 3rd choice AMs did not significantly decrease by participation in the ASP. The change in total AMU became more prominent over time, with a 16% (4%-26%) decrease in (linear) time trend per year.ConclusionsThis study shows that, although AMU in Dutch companion animal clinics was already decreasing and changing, AMU could be further optimised by participation in an antimicrobial stewardship programme.

Clostridium difficile is emerging as pathogen in both humans and animals. In 2000 it was described as one of the causes of neonatal enteritis in piglets, and it is now the most common cause of neonatal diarrhea in the United States. In Europe, C. difficile infection (CDI) in both neonatal piglets and adult sows has also been reported. Diagnosis of this infection is based on detection of the bacterium C. difficile or its toxins A and B. Most detection methods, however, are only validated for diagnosing human infections. In this study three commercially available enzyme immunoassays ( . We conclude that all tests had an unacceptably low performance as a single test for the detection of C. difficile in pig herds and that a two-step algorithm is necessary, similar to that in cases of human CDI. Of all of the assays, the real-time PCR had the highest NPV compared to both reference methods and is therefore the most appropriate test to screen for the absence of C. difficile in pigs as a first step in the algorithm. The second step would be a confirmation of the positive results by toxigenic culture.

Antimicrobial resistance (AMR) is an increasing threat, both in human and in veterinary medicine. To reduce the selection and spread of AMR, antimicrobial use (AMU) should be optimized, also in companion animals. To be able to optimize AMU, a feasible method to quantify AMU and information on current AMU are needed. Therefore, a method to quantify AMU was developed, using the number of Defined Daily Doses Animal (DDDA). This method was used to explore applied antimicrobial classes and to identify differences in prescribing patterns in time and between veterinary clinics. Antimicrobial procurement data of the years 2012-2014 were collected retrospectively from 100 Dutch veterinary clinics providing care for companion animals. The mean number of DDDAs per clinic per year decreased significantly from 2012 to 2014. A shift in used classes of antimicrobials (AMs) was seen as well, with a significant decrease in use of third choice AMs (i.e., fluoroquinolones and third generation cephalosporins). Large differences in total AMU were seen between clinics ranging from 64-fold in 2012 to 20-fold in 2014. Despite the relative low and decreasing AMU in Dutch companion animal clinics during the study, the substantial differences in antimicrobial prescribing practices between clinics suggest that there is still room for quantitative and qualitative optimization of AMU.