The guidelines are based on available scientific evidence, and for every combination of class of antimicrobials, swine disease and pathogen, an assessment of prudent use is provided in a simple spreadsheet online by the Danish Veterinary and Food Administration (DVFA).
The spreadsheet present all currently registered veterinary antimicrobial products for the specific diseases in drop down lists with recommended dosages and treatment periods registered along with a colour-coding indicating the most prudent choices based on four criteria: Efficiency, susceptibility, pharmacokinetics and human importance. The guidelines are dynamic lists, which can be changed on request or if new information or new antimicrobial agents emerge.
Download prudent use guidelines for pigs
The new guidelines are the third step elaboration of prudent use treatment guidelines; the guidelines are part of the ongoing risk management strategy in Denmark for optimisation of antimicrobial consumption and reduction of antimicrobial resistance. The DVFA commenced elaboration of dynamic prudent use treatment guidelines for food-producing animals, starting with swine in 2005, followed by a reviewed concept for treatment guidelines for cattle in 2008, and now these new dynamic evidence based prudent use treatment guidelines for swine.
The guidelines demonstrate the need for collaboration between the human and veterinary side in a one health concept in order to combat risk of development of resistant bacteria. The one health concept, results from a strong collaboration between all stakeholders in a task force hosted by the DVFA. Members of the task force are: the Danish Veterinary Association, the Danish Animal Health Industry, epidemiologists and risk assessors from the Danish Meat Association and DVFA, researchers in pharmacology and swine diseases from the Faculty of Life Sciences, Copenhagen University as well as researchers from the Statens Serum Institut, the National Food Institute and the National Veterinary Institute.
Based on the available evidence, the different classes of antimicrobials are assessed by the following four criteria: a) clinical documentation of efficacy, b) susceptibility based on national microbiological data, c) pharmacokinetics and d) risk profiling of the human health concerns when the antimicrobial agents are used for veterinary antimicrobial treatment. In the new dynamic guidelines, the actual ranking is based on the scoring shown in Table 1, and the documentation for the ranking is included in the guideline spreadsheet.
Table 1: Categorisation of antimicrobial agents in the guidelines
1 = documented in summary of product characteristics (SPC)
2 = documented in peer-reviewed papers, EMEA or FDA papers.
Percent susceptible, among isolates sent to the National Food Institute and National Veterinary Institute.
Score based on MICKill/MIC50: 1 = range 0 - 0.19; 2 = range 0.2 - 0.39; 3 = range 0.4 - 0.59; 4 = range 0.6 - 0.79 and 5 = >0.8
Based on estimated MICKill where 80% of the dosage is covered by a concentration above MIC50, estimated from national data
1 = very high; 2 = high; 3 = medium; 4 = low and 5 = very low. Follows FDA and OIE guidelines
The risk profiling is done according to the principles of FDA guidance 152 "Evaluating the safety of antimicrobial new animal drugs with regard to their microbial effects on bacteria of human health concern", as well as the principles in OIE-guidelines. For every antimicrobial group, it is estimated whether the probability for selection antimicrobial resistance, exposure of humans and human consequences are very high, high, medium, low or very low. Based on these estimates, a common estimate for the human health consequences of the use of this antimicrobial group for swine is estimated. The common estimate gives a qualitative ranking of the expected future human health consequences by antimicrobial usage for swine of the different antimicrobial groups (Table 1).
Another new feature is that recommendations of usage of antimicrobial classes for the specific diseases (site of action) and specific pathogens are indicated by three different colours - green, yellow and red - in order to simplify the veterinary practitioner’s choice of a prudent antimicrobial (Figure 1).
See figure 1 here
Green indicates antimicrobials that are recommended to be used for that specific disease and pathogen combination. The green-labelled antimicrobials will have susceptibility above 80%, good pharmacokinetics and a risk profiling of human health consequences assessed to have no or only low consequences and preferably also evidence based documentation of clinical efficacy. Examples of green-labelled antimicrobials with good ranking in all four categories for specific diseases and pathogens are: benzylpenicillinprocain, tiamulin, valnemulin and colistin sulphate.
Yellow indicates antimicrobials that can be used, but better alternatives are available.
Red indicates antimicrobials not recommended due to high human health consequence or a very low susceptibility. Examples of red-labelled antimicrobials are enrofloxacin, marbofloxacin, cefquinom and other cephalosporins, but also other antimicrobials with a low score on susceptibility for a specific pathogen will be labelled with a red colour.
To be used by the veterinary practitioners
The guidelines are directed towards veterinary practitioners. In Denmark, all veterinary medicinal products are prescription only and this places the veterinary practitioners as key persons in prudent antimicrobial usage. The veterinary practitioners may use the guidelines as a working tool in their counselling of preventive veterinary strategies in herds, thereby optimising antimicrobial usage with due consideration to both human and animal health.
They can look up a specific disease and pathogen in the guidelines, use the colours to choose a prudent antimicrobial and the drop down lists to find products, dosage and treatment period. If they want to know how or why a certain treatment have a good or pour ranking in one or more of the categories, they can use the documentation spreadsheets within the guidelines to study the evidence behind.