On-site tests for high priority foodborne pathogens and an assessment of their readiness for deployment.

On-site diagnostic tests can provide rapid detection of foodborne pathogens, help ensure food safety and aid in safeguarding public health. In this review, we discuss on-site diagnostic tests, their development for priority foodborne pathogens and analyse key barriers in their progression towards deployment. We assess the readiness of these tests using a deployment readiness level (DRL) framework which is an adaptation of the Technology Readiness Level (TRL) framework which focuses on the maturity of a technology. The DRL framework emphasises that diagnostic tests, even when using the same technology, can vary in their stage of development and thus require separate assessment. Only a limited number of tests based on technologies such as, loop-mediated isothermal amplification (LAMP), and portable real-time PCR have reached advanced DRLs with potential for application in the food sector. Most tests remain at stages lacking validation in the hands of end-users or, if validated, validation data is not publicly available for objective evaluation. The most prominent barriers include performance gaps compared to gold-standard methods, a funding gap between innovation and commercialisation, absence of integrated testing formats, unpublished validation data, and a lack of regulatory frameworks. Advancing on-site diagnostics will require aligning test development with areas of greatest impact and addressing these critical limitations.