Terrestrial Animal Health Code

Contents | Index Chapter 6.7. Section 6. Chapter 6.9.

Chapter 6.8.


Risk assessment for
antimicrobial resistance arising from the
use of antimicrobials in animals


Article 6.8.1.


Recommendations for analysing the risks to animal and public health from antimicrobial resistant micro-organisms of animal origin

  1. Introduction

    The use of antimicrobials for therapy, prophylaxis and growth promotion in animals can reduce their efficacy in animal and human medicine, through the development of antimicrobial resistant strains of pathogenic micro-organisms. This risk may be represented by the loss of therapeutic efficacy of one or several antimicrobial drugs and includes the emergence of multi-resistant micro-organisms.

  2. Objective

    The principal aim of risk analysis for antimicrobial resistance in micro-organisms from animals is to provide OIE Members with a transparent, objective and scientifically defensible method of assessing and managing the human and animal health risks associated with the development of resistance arising from the use of antimicrobials in animals.

  3. The risk analysis process

    The principles of risk analysis are described in Section  of this Terrestrial Code.

    A qualitative risk assessment should always be undertaken. Its outcome will determine whether progression to a quantitative risk assessment is feasible and/or necessary.

  4. Hazard identification

    For the purposes of this Chapter, the hazard is the resistance determinant that emerges as a result of the use of a specific antimicrobial in animals. This definition reflects the development of resistance in a species of pathogenic micro-organisms, as well as the development of a resistance determinant that may be passed from one species of micro-organisms to another. The conditions under which the hazard might produce adverse consequences include any scenarios through which humans or animals could become exposed to a pathogen which contains that resistance determinant, fall ill and then be treated with an antimicrobial that is no longer effective because of the resistance.

  5. Risk assessment

    The assessment of the risk to human and animal health from antimicrobial-resistant micro-organisms resulting from the use of antimicrobials in animals should examine:

    1. the likelihood of emergence of resistant micro-organisms arising from the use of antimicrobial(s), or more particularly, production of the resistance determinants if transmission is possible between micro-organisms;

    2. consideration of all pathways and their importance, by which humans could be exposed to these resistant micro-organisms or resistance determinants, together with the possible degree of exposure;

    3. the consequences of exposure in terms of risks to human and/or animal health.


Article 6.8.2.


Analysis of risks to human health

  1. Definition of the risk

    The infection of humans with micro-organisms that have acquired resistance to a specific antimicrobial used in animals, and resulting in the loss of benefit of antimicrobial therapy used to manage the human infection.

  2. Hazard identification

    The identification of the hazard must include consideration of the class or subclass of the antimicrobial(s). This definition should be read in conjunction with point 4) of Article 6.8.1.

  3. Release assessment

    A release assessment describes the biological pathways necessary for the use of a specific antimicrobial in animals to lead to the release of resistant micro-organisms or resistance determinants into a particular environment, and estimating either qualitatively or quantitatively the probability of that complete process occurring. The release assessment describes the probability of the release of each of the potential hazards under each specified set of conditions with respect to amounts and timing, and how these might change as a result of various actions, events or measures.

    The following factors should be considered in the release assessment:

  4. Exposure assessment

    An exposure assessment describes the biological pathways necessary for exposure of humans to the resistant micro-organisms or resistance determinants released from a given antimicrobial use in animals, and estimating the probability of the exposures occurring. The probability of exposure to the identified hazards is estimated for specified exposure conditions with respect to amounts, timing, frequency, duration of exposure, routes of exposure and the number, species and other characteristics of the human populations exposed.

    The following factors should be considered in the exposure assessment:

  5. Consequence assessment

    A consequence assessment describes the relationship between specified exposures to resistant micro-organisms or resistance determinants and the consequences of those exposures. A causal process must exist by which exposures produce adverse health or environmental consequences, which may in turn lead to socio-economic consequences. The consequence assessment describes the potential consequences of a given exposure and estimates the probability of them occurring.

    The following factors should be considered in the consequence assessment:

  6. Risk estimation

    A risk estimation integrates the results from the release assessment, exposure assessment and consequence assessment to produce overall estimates of risks associated with the hazards. Thus, risk estimation takes into account the whole of the risk pathway from hazard identification to the unwanted consequences.

    The following factors should be considered in the risk estimation:

  7. Risk management options and risk communication

    Risk management options and risk communication have to be continuously monitored and reviewed in order to ensure that the objectives are being achieved.


Article 6.8.3.


Analysis of risks to animal health

  1. Definition of the risk

    The infection of animals with micro-organisms that have acquired resistance from the use of a specific antimicrobial(s) in animals, and resulting in the loss of benefit of antimicrobial therapy used to manage the animal infection.

  2. Hazard identification

    The identification of the hazard must include considerations of the class or subclass of the antimicrobial(s). This definition should be read in conjunction with point 4) of Article 6.8.1.

  3. Release assessment

    The following factors should be considered in the release assessment:

  4. Exposure assessment

    The following factors should be considered in the exposure assessment:

  5. Consequence assessment

    The following factors should be considered in the consequence assessment:

  6. Risk estimation

    The following factors should be considered in the risk estimation:

  7. Risk management options and risk communication

    Risk management options and risk communication have to be continuously monitored and reviewed in order to ensure that the objectives are being achieved.

    The relevant recommendations (Articles 2.2.5., 2.2.6. and 2.2.7.) in the Terrestrial Code apply.

    A range of risk management options is available to minimize the emergence and spread of antimicrobial resistance and these include both regulatory and non-regulatory risk management options, such as the development of codes of practice concerning the use of antimicrobials in animal husbandry. Risk management decisions need to consider fully the implications of these different options for human health and animal health and welfare and also take into account economic considerations and any associated environmental issues. Effective control of certain bacterial diseases of animals will have the dual benefit of reducing the risks linked to antimicrobial resistance, in cases where the bacterial disease under consideration has also developed antimicrobial resistance. Appropriate communication with all stakeholders is essential throughout the risk assessment process.

2008 ©OIE - Terrestrial Animal Health Code

Contents | Index Chapter 6.7. Chapter 6.9.