Risk for developing tuberculosis among intravenous drug users with human immunodeficiency virus (HIV) infection

Approximately one third of people living with human immunodeficiency virus (HIV) infection are co-infected with tuberculosis (TB), and TB accounts for up to a third of deaths from AIDS worldwide. Injectable drug use is an important factor in epidemiology of both TB and HIV. This study was carried out to assess the risk of intravenous drug use for developing TB in HIV infected patients. A cross-sectional study was conducted from January, 2009 to December, 2011. Equal numbers of HIV seropositive patients with and without history of intravenous drug use (IVDU) attending Department of Microbiology, BP Koirala Institute of Health Sciences for CD4 cells counting were enrolled to study the prevalence of pulmonary tuberculosis. Three early morning sputum specimens on consecutive days were collected from all participants and processed for microscopy (Auramine-O and Ziehl-Neelsen staining) and culture on Lowenstein-Jensen (L-J) media. Observation was noted. Of a total of 336 subjects enrolled in our study, group I and group II comprised HIV patients with IVDU (n = 168) and without IVDU (n = 168), respectively. In group I, Mycobacterium tuberculosis was detected in 40 (23.8%) patients. There was no statistical association between duration of intravenous drug use and finding of M. tuberculosis positivity (p > 0.05). In group II, M. tuberculosis was detected in 32 (19%) patients. Univariate analysis revealed that TB in HIV seropositive patients appeared with higher frequency in intravenous drug users (odds ratio (ORa) = 1.3; CI 95%, 0.786 to 2.242) than the non-users. Average CD4 cells count among HIV positive patients in group I and II was 248.6 and 292.7, respectively; with 47 patients (27.9%) in group I and 40 patients (23.8%) in group II having counts below 200. Rate of TB is high in intravenous drug user populations infected with HIV.