WHO Medically Important Antimicrobial List 2024

WHO developed the first List of Critically Important Antimicrobials for Human Medicine (“WHO CIA List”) in 2005, now renamed the WHO Medically Important Antimicrobial List (“WHO MIA List”). In 2019, WHO Member States requested the Director-General to maintain and systematically update the WHO CIA List[1].

The WHO MIA List is a risk management tool that can support risk-based decision-making to minimize the impact on antimicrobial resistance in humans from the use of antimicrobials in non-human sectors. The target audience includes national regulators and policymakers in ministries of health and agriculture, authorities responsible for regulating, monitoring, and assuring the responsible and prudent use of antimicrobials, and professional prescribers in different sectors. Antibacterial agents are ranked into one of three categories using the following criteria: their relative importance for human medicine, the risk of developing resistance, and the implications for human health from their use in non-human sectors. The categories are: (1) critically important antimicrobial (CIA); (2) highly important antimicrobial (HIA); and (3) important antimicrobial (IA) to human medicine.

The WHO MIA List was developed in close collaboration with the Food and Agriculture Organization (FAO), the United Nations Environmental Programme (UNEP) and the World Organization for Animal Health (WOAH) as a joint effort to harmonize and align related guidance and lists developed by the four organizations. Best practice statements included in the document are aligned with the position of the Quadripartite organizations (FAO, UNEP, WHO, and WOAH) and are critical to preserving the effectiveness of the agents in the WHO MIA List. Further work is ongoing to harmonize guidance on the prudent use of antimicrobials across all four organizations and this WHO antimicrobial list and the WOAH List of antimicrobial agents of veterinary importance.