Of the 33.4 million people living with HIV in 2008, nearly a third were estimated to have latent or active tuberculosis (TB); of the 9.4 million cases of TB, an estimated 15% were coinfected with HIV. This journal article reviews the current knowledge of the HIV/TB syndemic (“the convergence of two or more diseases that act synergistically to magnify the burden of disease”) and the epidemiological, clinical, cellular, and molecular interactions between HIV and TB.
The authors observe that many socioeconomic determinants of TB are also drivers of risk behaviors for HIV transmission, and set forth findings indicating that HIV serves as a driver of TB at the population level. They discuss the effect of each disease on the other – TB appears to accelerate the progression of HIV disease, and for persons with TB, HIV increases the risk of progression to active TB in both primary TB infection and the reactivation of latent TB. The authors also describe in detail the effect of combination antiretroviral therapy, and the HIV/TB interactions at the cellular and molecular level.
The authors conclude by offering key topics on which further investigation is warranted, including prevention of TB infection in people with HIV, prevention of progression to active TB in people with HIV, and the effect of timely and appropriate treatment for people with both HIV and TB.