Institute of Social and Preventive Medicine (ISPM)

Drug-resistant tuberculosis: high mortality rate due to inaccurate tests

Mortality according to drug resistance, concordance or discordance of drug susceptibility test results, and treatment adequacy

08.02.2019 - Inaccurate tests carried out on tuberculosis patients in developing countries often fail to reliablydetect resistance to drugs, leading to incorrect treatment and a higher mortality rate. These are the results of study by an international group of researchers led by a team (Kathrin Zürcher, Marie Ballif, Lukas Fenner, Matthias Egger) at the University of Bern published today.

Around ten million people around the world develop tuberculosis every year and 1.5 million people die from tuberculosis each year. 87% of those affected live in or come from developing countries. According to WHO, resistance to drugs used to treat tuberculosis—as well as the proliferation of multi-resistant tuberculosis strains—is one of the most pressing global health problems. WHO sees an urgent need to improve quality and coverage of diagnosis and treatment of drug-resistant tuberculosis.

This was the starting point for a comparative study led by the Institute of Social and Preventive Medicine (ISPM) at the University of Bern, Switzerland. The study compared the results of tests to detect drug resistance in patients done in developing countries with the results of testing at the Swiss tuberculosis reference laboratory in Zurich. For the first time, researchers were able to demonstrate that many cases of drug resistance remain undetected due to inaccurate tests, and that this led to patients being treated incorrectly and, thus, to more deaths. The results were published in the prestigious journal Lancet Infectious Diseases today.