Applying a Systems Approach to Validation and Proficiency Testing in Plant Virology to Meet ISO 17025 Accreditation Requirements

Recent changes in European Union plant health regulations require diagnostic laboratories to obtain ISO/IEC 17025 accreditation for all tests on regulated pests conducted under official controls. However, meeting all requirements of this standard is challenging due to the vast number of pest, host, and matrix combinations that require test validation and proficiency testing. In plant virology, adopting a risk-based systems approach to validation can help to meet ISO/IEC 17025 accreditation requirements. This approach acknowledges that workflows, which may consist of single or multiple tests, are used for the detection and identification of specific viruses, viroids, and phytoplasmas. For each test within a workflow, validation is determined through a risk analysis based on its specific purpose, and the entire diagnostic process is validated through the combination of tests. This approach could fit within the definition of a “flexible scope” as defined by the European co-operation for Accreditation. When combined with diagnostic expertise and contextual understanding in plant health diagnostics, as well as proficiency testing at the method level, this approach improves overall diagnostic proficiency in a cost-effective way and may facilitate accreditation and compliance with plant health regulations in the European Union. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2026.