ABSTRACT
The human immunodeficiency virus (HIV) epidemic has had an enormous impact on tuberculosis (TB) worldwide. With the spread of HIV, incidence of TB rose dramatically both in endemic countries as well as in those with previously declining rates. By lowering host immune responses to mycobacteria, infection with HIV heightens the susceptibility to TB infection and the risk of progression to active disease. Because atypical clinical presentations and other concurrent infections are common, the diagnosis of TB is often delayed in HIV-infected individuals. On the other hand, in countries with a high prevalence of coinfection, increased awareness and clinical suspicion lead to many patients being started on anti-TB treatment without bacteriologic confirmation. Incidence rates ofTBhave risen toa greater extent than prevalence rates in settings with a high prevalence of HIV, suggesting that the duration of disease prior to diagnosis is shorter among coinfected patients in these settings (1). Common social risk factors such as poverty and crowded living situations place coinfected patients at a high risk for primary TB infection. All these factors, together with an accelerated course of disease, render HIV-infected patients with TB at high risk for death. In fact,
coinfected individuals have a higher mortality than those with TB alone, and, in turn, TB accounts for the majority of deaths in HIV-infected individuals.
