The global situation of MDR-TB

Area of Science:

• Public Health
• Infectious Diseases
• Epidemiology

Background:

• Drug-resistant tuberculosis has been documented since chemotherapy's inception, with early data primarily from developed nations.
• A 1992 congress highlighted a lack of global information on multidrug-resistant tuberculosis (MDR-TB), defined as resistance to isoniazid and rifampicin.
• The WHO/IUATLD Global Project on Drug-Resistance Surveillance (launched 1994) aimed to address this data gap.

Purpose of the Study:

• To determine the global magnitude of multidrug-resistant tuberculosis (MDR-TB).
• To identify regions with critical levels of MDR-TB.
• To inform control and containment strategies for MDR-TB.

Main Methods:

• Global surveillance data collection through the WHO/IUATLD Global Project on Drug-Resistance Surveillance.
• Analysis of drug resistance patterns in tuberculosis cases across surveyed countries.
• Mathematical modeling to estimate the global burden of MDR-TB.

Main Results:

• Globally, MDR-TB prevalence was a median of 1% in 64 surveyed sites, significantly lower than drug-susceptible tuberculosis.
• Specific "hot spots" with critical MDR-TB levels were identified in Estonia, Latvia, Russia (Ivanovo, Tomsk), and China (Henan, Zhejiang).
• Mathematical modeling estimated 3.2% (273,000 cases) of new global tuberculosis cases in 2000 were MDR-TB.

Conclusions:

• MDR-TB is currently characterized by local epidemics rather than a uniform global crisis.
• Effective control requires preventing new resistant strains via DOTS and judicious use of second-line drugs for MDR-TB treatment.
• Further data from non-reporting countries, particularly high-burden nations, are crucial for a comprehensive understanding.