Evaluation of the status of tuberculosis as part of the clinical case definition of AIDS in India

Abstract

Aim: To assess HIV associated tuberculosis in a high tuberculosis prevalence setting and its status in the clinical case definition of AIDS. Methods: All HIV patients attending the infectious disease clinic, Varanasi, India between January 2001 and December 2003 were included in the study. They were stratified into three distinct immunological categories depending on their CD4 levels in accordance to Centers for Disease Control (CDC) classification. Tuberculosis of different organs was defined as detailed below. Results: Tuberculosis was the commonest opportunistic disease, seen in 163 patients. Of these, 68 had exclusively pulmonary tuberculosis, 55 extrapulmonary disease, and 40 the disseminated form. Pulmonary and extrapulmonary tuberculosis had low positive predictive value (PPV) (51% and 42%) for CD4 levels of <200 when compared with the disseminated form (specificity 87% and PPV 75%). Among 86 patients with radiological evidence of tuberculosis, typical radiological features of post-primary tuberculosis were present in 60 cases (70%). Other features such as effusion (14 patients, 16%) and miliary shadows (12 patients, 14%) were comparatively rare. Conclusion: Keeping pulmonary and extrapulmonary forms of tuberculosis in AIDS defining illness should be reconsidered. In a similar way tuberculosis in HIV patients from areas endemic with tuberculosis occurs in patients with a wide range of immune status and has a better prognosis than other AIDS defining illnesses. Therefore the inclusion of tuberculosis in clinical case definition of AIDS is not justified.