DIAGNOSIS OF TUBERCULOSIS IN PATIENTS WITH PLEURAL EFFUSION IN AN AREA OF HIV-INFECTION AND LIMITED DIAGNOSTIC FACILITIES

In a prospective study of 118 patients with pleural effusion, tubercul osis (TB) was diagnosed in 112. In 84 patients the diagnosis of TB was made by detection of acid fast bacilli by stain (auramine, Ziehl-Neel sen) or by culture of mycobacteria (Lowenstein-Jensen medium) in pleur al fluid or pleural tissue (obtained by closed biopsy) or by the prese nce of caseating granulomas in histological sections. In 28 patients t he diagnosis of TB was considered probable, based on good response to anti-tuberculous therapy. The highest diagnostic yield was obtained by histology (85%), followed by culture of pleural biopsy (37%) and pleu ral fluid culture (36%). Pulmonary tuberculosis was found in 8 patient s and dissemination of TB to other sites in 25 patients of whom 20 wer e HIV positive. By logistic regression analysis we identified 2 indepe ndent diagnostic markers for TB pleuritis: pleural fluid protein >50 g /l (Odds ratio 12.1, 95% confidence interval (CI): 1.1-128.3) and aden osine deaminase of >10 U/l (Odds ratio 11.08, 95% CI: 1.3-96.4). We co nclude that conventional facilities of a referral hospital are suffici ent to diagnose tuberculous pleuritis as well as disseminated tubercul osis irrespective of HIV infection. However, for regions with overstre tched health services and high prevalences of tuberculous pleurisy in patients with pleural effusion eve suggest a simplified diagnostic app roach based on exclusion of other causes of pleural effusion by simple means and use of these diagnostic markers.