Tuberculosis researchers discuss challenges, next steps for addressing XDR-TB, MDR-TB in Africa at TB symposium

Sep 22 2008

As many as 30% of people with drug-resistant tuberculosis can be successfully treated with first-line drugs, Paul van Helden of the University of Stellenbosch's Center of Excellence for Biomedical TB Research said recently while presenting research on drug-resistant TB at a TB symposium in Maputo, Mozambique, Africa Science News Service reports.

Van Helden recommended scaling-up TB control efforts and increasing public support for institutionalized treatment to curb the spread of the disease. According to van Helden, routine drug-susceptibility tests underestimate the prevalence of drug-resistant TB, which accounts for 40% of all TB cases worldwide -- 20% of which are multi-drug resistant TB cases and 20% of which are extremely drug-resistant TB cases -- according to CDC estimates. XDR-TB is resistant to the two of the most potent first-line treatments and at least two of the classes of second-line drugs.

At the symposium, van Helden warned against inaction in managing MDR-TB and XDR-TB, adding that genotyping demonstrates that XDR-TB strains may have evolved from prevalent MDR-TB strains. Martin Grobusch of the National Health Laboratory Service, who also is chair of the Department of Clinical Microbiology and Infectious Diseases at the University of Witwatersrand, added that many factors contribute to the spread of drug-resistant TB in Africa, including a "massive number of cases, inadequate DOTS implementation, high treatment failures, low adherence to drugs." In addition, HIV prevalence, lack of access to health clinics, late detection of drug-resistant TB, inconsistent policy implementation and delays in receiving laboratory results also affect the spread of drug-resistant TB. Grobusch said that improvements in communication, infrastructure, information systems and transportation could help improve the situation (Neondo, Africa Science News Service, 9/18).