Surveillance of resistance to antituberculosis drugs in developing countries.

Resistance to antituberculosis drugs is caused by poor management of tuberculosis control. It gives rise to treatment failure, relapse, further transmission of resistant tuberculosis, and multidrug-resistant tuberculosis. Widespread occurrence of multidrug-resistant tuberculosis would constitute a major threat to tuberculosis control in resource-poor countries. Although the impact of HIV on drug resistance is not yet fully understood, it is likely to exacerbate problems caused by drug resistance. In particular, HIV-related adverse effects of thiacetazone, together with the risks of transmission of HIV by parenteral administration of streptomycin, reduce the armamentarium available to tuberculosis control programmes in high HIV prevalence countries, and could encourage the development of resistance to the remaining drugs. While the prime need is to ensure, by good management and supervision, that resistance does not occur in the first place, surveillance of drug resistance is essential to determine the current scale and nature of the drug resistance problem, as well as to define the correct solutions.