Tuberculin skin testing in intravenous drug users: differences between HIV‐seropositive and HIV‐seronegative subjects

Abstract

The prevalence of tuberculin skin test reactions among intravenous drug abusers and differences in tuberculin skin test positivity between HIV-seropositive and HIV-seronegative subjects were evaluated in a cross-sectional study of 1131 subjects. They were recruited from a therapeutic community, from those who attended the centre for the treatment of drug addiction and from those who visited for any reason an acute tertiary-care hospital in Vitoria-Gasteiz, Basque Country (Spain). All subjects underwent skin testing with purified protein derivative (PPD) tuberculin and testing for HIV antibodies. CD4(+) T-lymphocyte count was determined in HIV-seropositive individuals. Positive PPD tests were recorded in 35% of drug users who were HIV-seropositive and in 65% in those who were HIV-seronegative. In the HIV-infected group, there was a significant association between results of the tuberculin test and CD4(+) T-lymphocyte count. When the CD4(+) T-lymphocyte count was > or = 500 cells/mm(3), percentages of positive PPD tests were similar in HIV-seropositives and HIV-seronegatives (47% versus 65%) but when the CD4(+) count was < 500 cells/mm(3), positive PPD tests occurred in only 21% of HIV-seropositives. The PPD test showed a decreased sensitivity for detecting tuberculosis infection in HIV-infected intravenous drug users with CD4(+) T-lymphocyte counts fewer than 500 cells/mm(3).

Latent tuberculosis infection in a Malaysian prison: implications for a comprehensive integrated control program in prisons

“…This study corroborates earlier reports that the immunosuppressive effect of HIV infection itself impairs TST reactivity and may contribute to cutaneous anergy and potentially reduces its ability to detect LTBI [36,37]; this may be particularly true since almost half (45.6%) of the HIV-infected prisoners in this sample had a CD4 ≤350 cells/μL. Among PWIDs in the U.S., Graham et al .…”

Latent and Active Tuberculosis: Evaluation of Injecting Drug Users

“…The possible reason for these discrepancies can be explained by the differences between CD4+ counts in HIV infected patients which results different immunoresponse to PPD test. As Portu et al (19) indicated that in HIV positive group there was a significant association between results of PPD test and CD4+ T-lymphocyte count. The rate of positive PPD test was similar in HIV seropositive and seronegative cases when the CD4+ count was equal or greater than 500 cells/mm3.…”

Mycobacterium tuberculosis infection among persons who inject drugs in San Diego, California

“…Somewhat paradoxically, HIV prevalence was lower among PWID who were QFT-positive, but others have reported similar findings. 17,24 Other studies used TST, which is known to have reduced sensitivity among individuals with HIV due to immunosuppression. The current study used QFT, which has greater sensitivity than TST among individuals with HIV and produces indeterminate—rather than negative—results if the subject is severely immunosuppressed.…”