Twenty years of global surveillance of antituberculosis drug resistance

The development of drug resistance in Mycobacterium tuberculosis was first documented in the late 1940s, soon after antibiotic therapy was introduced for tuberculosis treatment.It quickly became obvious that combination chemotherapy could prevent the emergence of drug resistance and that patients infected with drug-resistant strains were less likely to be cured.Nevertheless, it was only in the early 1990s that drug-resistant tuberculosis began to receive global attention as a public health threat. This coincided with the detection of outbreaks of multidrug-resistant tuberculosis (defined as resistance to at least rifampin and isoniazid) that were associated with high mortality among patients coinfected with HIV. The urgent need for a global mechanism to monitor the emergence and spread of resistance to antituberculosis drugs became clear.