Epidemiology of HIV-TB in Asia.

Tuberculosis (TB) has, for centuries, continued to remain a public health problem of enormous importance, particularly in the developing world, taking a heavy toll of those at their prime of life. The emergence of human immunodeficiency virus (HIV infection) and its close association with TB poses an even greater challenge to the health systems in general and TB programmes in particular, in African and Asian countries. HIV is considered to be the most potent risk factor for progression to active TB among those infected both with TB and HIV; as a result, TB is the most common life threatening opportunistic infection associated with HIV, and biggest cause of death among patients with acquired immunodeficiency syndrome (AIDS). In areas hard-hit by HIV, TB is increasing, leading to greater case load, thereby overstretching the already fragile health infrastructure. The deadly relationship between HIV and TB, each potentiating the effect of the other, requires a clearly defined strategy taking into consideration the natural history of the co-infection and its progression to clinical TB (and AIDS). It is clear that the only way to fight this is by bringing the two programmes to join forces and work creatively and innovatively. The strategy should include not only preventing HIV through community-based behavioural interventions and limiting progression to clinical TB through the use of isoniazid preventive therapy, but also early diagnosis and treatment of HIV-associated TB and AIDS using DOTS strategy and combination antiretroviral therapy respectively. The strategy probably would not succeed unless both the programmes are first strengthened before attempting to forge collaboration based on mutual strengths and comparative advantages. In addition, mobilizing national and international response, building partnerships and mobilizing resources will help a great deal in mounting an appropriate and effective response to HIV/TB in the Asian context.