In this preprint, the CRyPTIC project proposes the maximum value of minimum inhibitory concentration (MIC) for 13 different anti-TB drugs below which a sample can be considered to be ‘genotypically wild-type’.

It is necessary to establish these values, called epidemiological cutoff values (ECOFFs or ECVs), so that the MICs measured can be converted into binary (resistant/susceptible), or in the case of three drugs ternary (resistant/intermediate/susceptible), predictions.

The preprint draws on 20,637 clinical isolates collected by 14 CRyPTIC laboratories based in 11 countries on five continents.