Increasing Drug Resistance of Mycobacterium tuberculosis in a Medical Center—What About in Taiwan Overall?

Abstract

Mutation of Mycobacterium tuberculosis in resistance to tuberculosis drugs occurs spontaneously and at random,1 but clinically relevant drug resistance is associated with antituberculosis treatment, appears by selective multiplication of resistant mutants during treatment (acquired resistance), and by transmission of drug-resistant organisms (primary resistance). Proper use of antituberculosis drugs is essential in preventing drug resistance in tuberculosis. The prevalence and trend of drug resistance in tuberculosis is an important indicator of the quality of tuberculosis services.2–8 In 1994, the World Health Organization and the International Union Against Tuberculosis and Lung Disease launched the Global Project on Antituberculosis Drug Resistance Surveillance. The objectives of the Global Project are to measure the prevalence of antituberculosis drug resistance worldwide using a standardized methodology, to monitor the trend of drug resistance, to study the correlation between the level of drug resistance and treatment policies in different settings, and to evaluate the efficiency of treatment programs.9 To date, four global reports on antituberculosis drug resistance in the world have been published.2–5 Guidelines for surveillance of drug resistance in tuberculosis emphasize the following principles:9 1. The sample of specimens should be representative of the tuberculosis patients in the country/geographical setting under study and the sample size should be determined to permit standard epidemiologic analysis. 2. The patient’s history should be carefully obtained to determine whether or not the patient has previously received antituberculosis drugs, which is essential to distinguish between drug resistance among new cases and that among previously treated cases. 3. Optimal laboratory performance should be ensured and maintained through links with a supranational reference laboratory. Several facility-based surveys on drug resistance in tuberculosis in Taiwan were published in past decades.10–19 These reports indicated the importance of and the interest in this subject. However, the findings of these facility-based investigations cannot be generalized to the overall population of tuberculosis patients with certainty and have a limited role in monitoring the trend of drug resistance in tuberculosis. Surveys undertaken with a nationwide representative sample may be more widely applicable. An article, published in the March 2008 issue of this journal, which reported increasing drug resistance of M. tuberculosis in a medical center in northern Taiwan highlighted the problems.18 Su et al18 reported the prevalence of drug resistance in a total of 611 non-duplicate M. tuberculosis isolates from culture-proven tuberculosis cases