[Treatment of tuberculosis infection]

Tuberculosis is a chronic bacterial infection caused by Mycobacterium tuberculosis. It continues as an important cause of morbidity and mortality worldwide, especially in impoverished countries and where human immunodeficiency virus infection is endemic. The modern treatment of tuberculosis is based on the administration of effective drugs. Regimens do not differ for pulmonary and extra-pulmonary tuberculosis. In order to prevent the emergence of drug-resistant organisms, which is present initially in very small numbers, at least two effective drugs are always required. Short-course therapy has been developed to mitigate the consequences of patient default. It is best considered as consisting of two phases. An initial 2-month intensive phase of daily therapy should include isoniazid, rifampin, ethambutol and pyrazinamide. A consolidation phase of daily therapy with isoniazid and rifampin should be continued for an additional 4 months, preferably more for special clinical circumstances. This standardized drug strategy is successful only if the resources conserved by shortening treatment are used to maintain patient compliance. Completely supervised regimens have been also developed with success. Defaults lead not only to treatment failure but also the emergence and transmission of drug-resistant organisms. Treatment of confirmed or suspected drug-resistant tuberculosis is difficult and should only be made on experts consultation. More difficult to use and/or less effective than first line drugs, second line drugs could be chosen and associated. However drug toxicities should be monitored, with greatest concern to hepatitis. Follow-up of patients must be organised until 2 years after the completion of therapy to detect relapses. Treatment includes prophylactic measures which are a major modality for decreasing the spread of infection.