The "antibiotic-resistance" phenomenon and the Ministry of Health guidelines on the use of antibiotics in farms
Since the discovery of penicillin, in 1929, antibiotics have been a powerful tool alongside public medicine, for the treatment of bacterial infections of important infectious diseases with high incidence and with levels of lethality relevant to humankind. In the last forty years, they have been of great support to livestock production, encouraging the increase of the availability of animal proteins for developing countries, and indirectly contributing to the improvement of the "health" conditions of the new generations. However, the use of antibiotics is not free from "side effects". In fact, the use of various classes of molecules with antibiotic action has unfortunately favoured the "selection" and the diffusion of resistant populations of pathogenic and opportunistic bacterial agents. On the one hand, the phenomenon of antibiotic resistance is a "natural phenomenon". It is based on the selection of organisms able to survive in a given unfavourable environment, thanks to genetic mutations or for acquisition from other organisms of resistance genes already "pre-constituted". On the other hand, the use of antibiotics in the human and in the veterinary sectors has greatly amplified this phenomenon
Currently, almost all the classes of antibiotics used in human therapy are registered for veterinary use. The availability and the quantities used in the veterinary sector have favoured in the last decades the emergence and diffusion of resistance to all classes of antibiotics used in bacteria of animal origin, including zoonotic (e.g. Salmonella, Campylobacter) and opportunist bacteria (e.g. Escherichia coli, Enterococcus sp.).
In recent years, the phenomenon of antibiotic resistance is amplified and accelerated by excessive and/or inappropriate use of antibiotics, both in human and veterinary medicine. Antibiotics, exerting strong selective pressures on the microbial population, can produce deleterious effects on the health of humans and animals due to the loss of efficacy of the therapies with consequent risk of greater severity and /or spread of the diseases.
The importance of the "antibiotic-resistance" is not recent. Back in the 1998, the World Health Organization (WHO) adopted a resolution that formally invited Member States to take counter-measures against antibiotic resistance. More recently, the European Centre for Disease Prevention and Control (ECDC), the European Medicines Agency (EMA), and the European Food Safety Authority (EFSA) estimated that around 25,000 patients die each year for infections caused by multi-resistant bacteria, and the relative costs are estimated at around 1.5 billion euro per year.
From 2019, with the entry into force of the electronic veterinary recipe and the computerized system for traceability of the drugs, it will be easier to monitor the correct use of antimicrobials and, above all, to reinforce the antimicrobial-resistance actions.
The "Guidelines for the promotion of the prudent use of antimicrobials in zoo technical farms for the prevention of antimicrobial resistance and alternative proposals", has been set up by the Section for Pharmacological Surveillance on Veterinary Medicinal Products of the Technical Committee for Nutrition and Animal Health (Ministerial Decree of 30 March 2016). The Guidelines provide useful indications to prevent the inappropriate use of antimicrobials, which, in veterinary medicine, represent a real risk for animal health and for breeders, and is responsible for both the reduction of production and the inefficiency of herds. The document is a practical guide for competent Authorities, freelance veterinarians and sector operators, and provides guidance on reducing the inappropriate use of antimicrobial medicines, for a prudent and conscious approach to animal health, animal husbandry and therefore of consumers. Moreover, the strict observance of the principles contained in the guidelines can maximize the number of healthy animals, minimizing the need to resort to the use of antimicrobials. The document, to be evaluated and customized for each farm, is enriched by a study, the first of its kind, on the vaccination strategy as an alternative to the use of antibiotics, especially in cases where they are used, in accordance with the conditions established at the time of marketing authorization, for the prevention of diseases of bacterial origin.
Specifically, the guidelines dedicate particular attention to the measures to be implemented to counteract the antibiotic-resistance phenomenon, measures concerning in particular hygiene, nutrition, control of infectious diseases and vaccination campaigns, taking into account the possibility of administering vaccines instead of antibiotics.
Improvement actions
- Abandoning the use of antibiotics for preventive purposes or, if considered indispensable, only as a result of suitable documented justifications;
- Predict their use only Follow Using accurate diagnostic tests, including sensitivity tests;
- Pay particular attention to compliance with the indications and conditions of use envisaged for achieving the results shown in the indications;
- Evaluate the efficacy of antibiotics and the validity of their associations and promptly report any adverse reactions;
- Promote /update training / information aimed at understanding the incidence of existing / persistent bacterial diseases in different geographic areas;
- Promote the availability of immunizing devices;
- Keep an updated list of all the stabulogens vaccines produced by the Public animal health research Institutes (Istituti Zooprofilattici Sperimentali) and verify their congruity with regards to the diagnostic tests performed, the epidemiological situation reported for the areas of specific competence, and the monitoring of their effectiveness in the field;
- Promote the availability of diagnostic tools.
Recommendations for prudent use
For prudent use we mean "a series of practical measures and recommendations that confer benefits to animal and public health" (OIE - Terrestrial Code) or "the use of antimicrobials that maximizes the therapeutic effect and minimizes the development of the antimicrobial- resistance "(WHO). In practice, through "prudent use" it is possible to:
- Preserve and maintain the therapeutic efficacy and safety of antimicrobials;
- Keep animals healthy;
- Prevent and/or reduce the selection of resistant microorganisms, the transfer of resistance determinants;
- Maintain the efficacy of antimicrobials used in human medicine;
- Protect consumer health by ensuring the safety of food of animal origin, in terms of both residues and the transfer of resistant microorganisms to humans.
Vaccines for the reduction of the use of antibiotics
Vaccination can provide a valuable aid to strategies to reduce the use of antimicrobials. The adoption of targeted company vaccination programs and their adaptation according to the monitoring of the health status of the farm, through laboratory diagnostics and surveillance at the slaughterhouse, remain fundamental elements.
The vaccination plans must be set according to the characteristics of the vaccine adopted (type, onset and duration of immunity, etc.) and vice versa. Vaccines must be chosen based on their characteristics of safety and efficacy and administered correctly. In particular, they must be stored and administered according to the indications contained in the Summary of Product Characteristics. In special situations, where the veterinarian sees the opportunity, in order to limit the use of antimicrobials, it is possible to resort to the use of stabulogen vaccines.
In conclusion, an integrated approach to the phenomenon of antimicrobial resistance plays a fundamental role in the prevention of diseases. It is necessary to promote compliance with animal welfare conditions, proper nutritional management, the implementation of appropriate biosecurity and hygiene measures, through programs for the eradication and monitoring of infectious diseases and appropriate animal vaccination campaigns.
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References
- Ministero della Salute. Sezione per la Farmacosorveglianza sui medicinali veterinari del Comitato tecnico per la nutrizione e la sanità animale. Linee guida per la promozione dell’uso prudente degli antimicrobici negli allevamenti zootecnici per la prevenzione dell’antimicrobico-resistenza e proposte alternative”, 2018.
Web References
- http://www.quotidianosanita.it/scienza-e-farmaci/articolo.php?articolo_id=65995
- http://www.anmvioggi.it/in-evidenza/67104-uso-prudente-negli-allevamenti-dal-minsal-una-linea-guida.html
- https://www.anmvi.it/anmvi-notizie/814-pubblicato-il-piano-nazionale-contro-l-antibiotico-resistenza.html
Simona Iannetti
Centro di Rreferenza per l’Epidemiologia Veterinaria, la Programmazione, l’Informazione e l’Analisi del Rischio
Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale"
