Tuberculosis and the poverty-disease cycle

On 24 March 1882, Robert Koch announced his discovery of the cause of tuberculosis, and since 1982 the anniversary date has been designated World TB Day2. Despite the declaration of tuberculosis as a global emergency by the World Health Organization in 1993, the incidence of the disease continues to increase world-wide. It is the most prevalent infectious cause of death, killing around 3 million people, principally young adults in the world's poorer countries, each year2. Matters have been made worse by the HIV pandemic and the emergence of multidrug resistance. Infection by HIV greatly increases the likelihood that a person infected with the tubercle bacillus will develop active tuberculosis: in 1999, HIV infection will account for an estimated one million additional cases of tuberculosis10% of the total number of cases-and tuberculosis will cause 30% of the predicted 2.5 million AIDS-related deaths3. At present only 2% of cases of tuberculosis are multidrug resistant but the rate is much higher in certain 'hotspots', including parts of the former USSR4. Why does tuberculosis continue to flourish despite the availability of therapy that is both highly effective and, in terms of years of human life saved, highly cost-effective5? To address this paradox, the World Health Organization has advocated DOTS (Directly Observed Therapy, Short course), hailed by some as the medical breakthrough of the 1990s6. This strategy calls for government commitment to tuberculosis control programmes, a regular supply of antituberculosis drugs, microscopy services for diagnosis, evaluation of the impact of the programme and administration of the drugs under direct supervision. The last component is regarded by many as the key to success-but the implication is that failure to control tuberculosis is the result of deviant behaviour by 'non-compliant' patients. Lately, however, the concept of compliance has been criticized by social scientists and anthropologists who postulate that non-compliance stems from a multitude of factors over which the patient has little or no control. Thus, )768