Tuberculosis in HIV-infected persons in British Columbia during the HAART era

Prior to the introduction of highly active antiretroviral therapy (HAART), active tuberculosis (TB) was a major contributor to HIV-related morbidity and mortality in Canada and other low-incidence regions. We performed this study to examine TB incidence, clinical manifestations and screening uptake in HIV-infected TB patients during the era of HAART therapy.

We performed a retrospective study on all HIV-infected TB patients in British Columbia over a 10-year period (2003-2012). Demographic and clinical characteristics were extracted along with screening and treatment outcomes. Trends in provincial TB incidence, HIV testing and HAART prevalence were also examined.

In total, 2,839 TB cases were identified in BC during this period, including 129 HIV-infected TB patients. Surprisingly, only 64 HIV-infected TB patients (50%) had a documented screening tuberculin skin test (TST) prior to TB diagnosis. Of the 39 HIV-infected TB patients with prior TST positivity, 38 (97.4%) had not completed a course of isoniazid preventive therapy. TB incidence decreased significantly in the HIV-infected population of BC over the study period, from 1.9 to 0.5 TB cases per 1,000 HIV-infected individuals (p<0.001).

The incidence of HIV-TB decreased significantly over the past decade despite suboptimal latent TB infection screening and prevention practices. This decrease in TB incidence is likely attributable to the increased uptake of HAART. Consideration should be given to intensifying prevention efforts to accelerate TB elimination in HIV-infected populations in low-incidence regions.