Date:12/10/2006 URL: http://www.thehindu.com/2006/10/12/stories/2006101201621000.htm

Opinion - Editorials

A warning signal

The recent outbreak of a highly virulent, extremely drug resistant tuberculosis strain (XDR-TB) — in KwaZulu-Natal province in South Africa — highlighted at the XVI International AIDS Conference in Toronto in August has added a disturbing dimension to the fight against tuberculosis. According to the data presented at the conference, of the 536 patients tested, 53 were found infected with XDR-TB; and 52 of these — many of whom tested positive for HIV — had fallen prey to the new strain within 25 days. This is not the first time that such strains have been identified. A survey carried out between 2000 and 2004 by the World Health Organisation and the Atlanta-based Centers for Disease Control and Prevention, which identified these strains in all regions of the world, confirms their prevalence. As an editorial in a recent issue of the British Medical Journal points out, the emergence of such strains was only to be expected, given the poor control practices. If the global incidence of tuberculosis is estimated to be growing at one per cent a year, about 4.5 lakh new cases are of the multidrug-resistant tuberculosis (MDR-TB) type — clearly the result of the failure of all stakeholders to adhere to correct strategies for fighting TB, despite the extensive adoption of the directly observed treatment short-course (DOTS).

While treating multidrug-resistant TB is possible by using at least four second-line drugs, treating patients suffering from extremely drug-resistant TB is currently not possible as the bacilli are resistant to three or more of the six classes of second-line drugs. That the possibility of developing a new class of TB drugs is at least four years away further compounds the problem. Though the fact that "... a strain resistant to so many drugs is not virulent enough to make healthy people seriously ill," as reported in Nature, is comforting, it can prove lethal to those who are HIV positive, estimated to number over five million in India. The only recourse, therefore, is to ensure that the incidence of multidrug-resistant TB is reversed. Adoption of incorrect prescription practices by many private practitioners is one of the major contributory factors. Despite the DOTS programme being in place throughout the country, and the prevalence of multidrug-resistant TB well known, estimates on a national scale are not available. With the emergence of XDR-TB, the original road map to have these estimates by 2010 covering nearly 50 per cent of the population has to be revisited. Concerted efforts are needed to make the DOTS-Plus programme, designed to address the management of multidrug-resistant TB, operational quickly. In the wake of XDR-TB, there is no room for complacency.