Extremely drug-resistant tuberculosis strain emerges in South Africa

September 10, 2006 New research findings from South Africa on an extremely drug-resistant (XDR) strain of the bacterium that causes tuberculosis (TB) alarm experts. XDR-TB is defined as resistance to three or more second line antibiotics for TB. The condition remains treatable with other types of medications, but those are less effective, costlier and toxic. If the afflicted persons can't be diagnosed timely and given proper treatment, they can die within a month. Of 53 patients who had this form of the lung infection in the study, 52 died, reports ABC News.

Dr. Tony Moll discovered the Extremely Drug Resistant Tuberculosis (XDR-TB) in the South African region KwaZulu-Natal. In an interview, he said the new variant was "very highly troubling and alarming because of the very high fatality rate." Some patients might have contracted the bug in the hospital, Dr. Moll thinks, and at least two were hospital health workers. In one year's time, an infected person may infect 10 to 15 close contacts. However, the percentage of XDR-TB in the entire group of people with tuberculosis still seems to be low; 6,000 of the total 330,000 people infected at any particular moment in South Africa.

The typical symptoms of TB (like prolonged coughing, fever, night sweats, weight loss and chest pain), and signs on X-ray are identical for XDR-TB. To ascertain the presence of this resistant form, a laboratory test on the patient's sputum is necessary, but these tests are often too expensive in the poor countries where TB is present. Also, these countries frequently have high HIV-rates too; 44 patient's in the study by Dr. Moll were seropositive. These patients are particularly vulnerable. Dr. Karin Weyer, director of the South African Medical Research Council's Unit for TB Research, cautioned that "In a country with such high prevalence of HIV, the emergence of XDR-TB is a nightmare." Because TB is often a hallmark of AIDS, many people afraid of the social stigma don't seek medical attention.

These distressing findings urged a two-day meeting in Johannesburg to discuss the situation. Experts like Dr. Moll believe the new strain is also present in other provinces than Kwazulu-Natal. Conference organizers report cases in Mozambique and Botswana too. The World Health Organization has called for renewed efforts to combat the disease. Meanwhile, officials of the Health Ministry are suspected to be enforcing a media ban on the topics of AIDS and possibly TB.

During the 1990s, multidrug-resistant tuberculosis (MDR-TB), defined as resistance to at least isoniazid and rifampin, emerged as a threat to TB control, both in the United States and worldwide.