Reg. (EU) n. 2019/6 (VMP Regulation) will be applicable from 28 January 2022 and will deeply change the use of antimicrobials in veterinary medicine. Thus, this is something concerning also the dairy industry.
We discussed the impact on prophylactic treatments in a recent article (read Blanket dry cow therapy, ban on prophylaxis from January 2022. Any alternative? Selective treatment).
Among the key measures, the VMP Regulation forms the basis for restrictions on those products used both in human and veterinary medicines. The aim is preserving the efficacy of antibiotics that are of critical importance for the treatment of infections in humans. Restrictions on these products are needed since antimicrobial resistant bacteria can stem from the use of antimicrobials in food animals and spread to humans through the food chain.
Article 37 of the VMP Regulation establishes the reasons for refusal of marketing authorasitation of veterinary medicinal products (VMPs). In particular, in paragraphs from 3 to 6 are defined the rules for refusal of antimicrobial VMPs when they are reserved for treatment of certain infections in humans. Moreover, the European Commission shall adopt delegated acts to supplement the VMP Regulation “by establishing the criteria for the designation of the antimicrobials which are to be reserved for treatment of certain infections in humans in order to preserve the efficacy of those antimicrobials”. In doing this, it will consider the scientific advice of relevant Union agencies, namely EMA, EFSA and others.
Let’s step back a little and make an overview on current aspects related to critically important antibiotics (CIAs) for humans. They are the most important antimicrobial products for treating infections in humans. According to the World Health Organisation’s categorisation, CIAs can be Highest Priority (Category 1 – their use in prophylaxis in animals should be avoided) and High Priority (Category 2 – antibiotics that pose a threat to human health if used in animals).
In 2019, the WHO updated the CIA list. With it, WHO developed and implemented criteria to rank antimicrobial products on the basis of their relative importance in human health.
The aim of the list is to help preserve the effectiveness of antimicrobials available to humans today by promoting their prudent use both in human and veterinary medicine. It includes also the Highest Priority CIAs, namely: quinolones, 3rd and higher generation cephalosporins, macrolides and ketolides, glycopeptides, and polymyxins.
Being OZOLEA at the forefront in the fight against AMR in dairy cows, in particular studying and developing tools for supporting the udder tissue functionality, it is worth mentioning the reason why quinolones and cephalosporins, used in dairy cattle to treat clinical and sub-clinical mastitis caused by E. coli, are included in this Category.
Quinolones are one of the few available substances to treat serious Salmonella and E. coli infections in humans. Also, they are known for they ability to select for quinolone-resistant Salmonella and E. coli in animals. Same issue for 3-rd and higher generation cephalosporins: they are one of the few available therapies for serious Salmonella and E. coli infections in human medicine, particularly in children and are known to select for cephalosporin-resistant Salmonella and E. coli in animals. The incidence of human disease due to Salmonella and E. coli is substantially high: thus, they are needed as the last resort for treatment in human medicine.
At the EU level, last year the European Medicines Agency (EMA) updated its scientific advice, prepared by the AMEG (Antimicrobial Advice Ad Hoc Expert Group) on the categorisation of antibiotics. EMA encourages veterinarians to check and consider this update when prescribing antibiotics for animals. It does not replace general guidelines, and other aspects (Summary of Product Characteristics, restrictions around use in food-producing species, regional peculiarities of disease and AMR, national policies, etc.) should also be considered.
This document is in line with the One-Health approach (see OZOLEA’s article “The One Health approach against antimicrobial resistance”). The new classification introduced by the AMEG currently comprises four categories:
A) “Avoid”: it includes antibiotics currently not authorised in veterinary medicine in the EU. They may not be used in food-producing animals and may be used in individual companion animals only by way of exception;
B) “Restrict”: this category rank critically important antibiotics (quinolones, 3rd- and 4th-generation cephalosporins, polymyxins) in human medicine and their use in animals should be restricted to mitigate any risk related in public health;
C) “Caution”: this category refers to those antibiotics which alternatives in human medicine are generally available in the EU, but only few alternatives exist in specific veterinary indications. Their use should be made only when there are no clinically effective antimicrobials in Category D;
D) “Prudence”: it includes antibiotics intended to be used as first line treatments, whenever possible. These products can be used in animals prudently: therefore, users should avoid unnecessary use and long treatment periods, limiting group treatment to situations in which individual therapy is not feasible.
In EMA’s document, the route of administration was also considered to evaluate its impact on selection of AMR.
