Drug susceptibility testing and mortality in patients treated for tuberculosis

Please see this useful study which compared the results of drug-susceptibility testing for TB (and patient outcomes) at the local level in Côte d’Ivoire, DRC, Kenya, Nigeria, South Africa, Peru, and Thailand, with the results obtained in a reference laboratory at the Swiss National Center for Mycobacteria. Locally done DST included Xpert MTB/RIF, line probe assays, and solid or liquid cultures, while the reference lab used MGIT liquid cultures for DST.

The study showed about 20% discordance between DST done in countries versus results obtained at the Swiss reference lab. Compared with concordant DST results, the adjusted odds ratio of death was 7·33 (95% CI 2·70–19·95) for patients with discordant results potentially leading to under-treatment. Everyone in the study received DST and there is no control group where DST was not routinely done. This is relevant because DST is not routinely done for TB patients in most low and middle-income countries. Patient outcomes in such settings will likely be much worse than what was found in this study where everyone received some DST.

Zürcher_LanectID_2019 (1).pdf (216.0 KB)