Tuberculosis: current trends in diagnosis and treatment.

Among communicable diseases, tuberculosis (TB) is the second leading cause of death worldwide, killing nearly 2 million people each year. It is estimated that about one-third of the world population are infected with TB (2 billion people) and about 10% of this figure will progress to disease state. Most cases are in the less-developed countries of the world. Tuberculosis incidence has been on the increase in Africa, mainly as a result of the burden of HIV infection. Definitive diagnosis of tuberculosis remains based on culture for Mycobacterium tuberculosis, but rapid diagnosis of infectious tuberculosis by simple sputum smear for acid fast bacilli remains an important tool, as more rapid molecular techniques are being developed. Treatment with several drugs for 6 months or more can cure more than 95% of patients. Direct observation of treatment, a component of the recommended five-element DOTS strategy, is judged to be the standard of care by most authorities. Currently only a third of cases worldwide are treated using this approach. There may be need to modify the treatment modalities especially with the choice of drugs and duration of therapy when TB infection occurs in special situation like pregnancy, liver disease, renal failure or even in coexistence with HlV/AIDS or the drug resistant state.