It is critical that HIV programs include a strong TB component, the second pillar of PIH’s approach to comprehensive care. HIV infection is the most potent risk factor yet identified for the development of TB. HIV infection enhances susceptibility to TB infection; facilitates the progression of latent infection to active TB; and increases the likelihood of treatment failure, relapse, and reinfection. Due to this biologically mediated risk and the ubiquitous and aggressive nature of TB in the developing world, TB is the most common cause of death in HIV-positive persons worldwide.³⁰

HIV-positive persons are 100 times more likely than HIV-negative individuals to develop active TB.^31–33 Additionally, molecular studies have confirmed that HIV-positive persons are more susceptible to exogenous re-infection by a second strain of TB, even after adequate anti-TB treatment has been provided. ^34–37 The risk of poor response to TB treatment—failure, relapse, and death—is also greater among HIV-positive individuals.^38–41 In addition to the markedly increased risk of developing active TB, once a person who has HIV develops active TB, the progression to AIDS and death is more rapid than for HIV-positive patients who do not have active TB.^42–44 However, when indicated, ART can improve survival in co-infected patients and decrease the risk of the progression of HIV to AIDS.⁴⁵