Diagnostic methods of primary tuberculous pleural effusion in a region with high prevalence of tuberculosis - A study in Mexican population

Study objectives. 1) To determine the age distribution of the patients with pleural tuberculosis in a region with high prevalence of tuberculosis; and 2) to evaluate the efficiency of the methods used in its diagnosis. Setting. The National Institute of Respiratory Diseases in Mexico City, a tertiary reference center for pulmonary diseases. Design. A retrospective study. Patients. 452 consecutive inpatients with diagnosis of pleural effusion from January 1991 to September 1996 were reviewed: 133 patients had a diagnosis of tuberculous pleural effusion of primary origin without parenchymal abnormalities by chest roetgenogram. The others were excluded because of reactivated tuberculosis or non-tuberculous effusion. Measurements and results. The patients had a mean age of 42 +/- 17 years (98 male, 35 female). Pleural granulomas in the morphological study were found in 87% whereas the baciloscopy and the culture of the fluid were positive in only 8% and 19% respectively. The determination of adenosine deaminase (ADA) gave a diagnostic yield of 84%. conclusions. 1) Primary tuberculosis pleural effusion, reported in the English literature, was also present in our adults; 2) the pleural biopsy continued to be the most effective method in the diagnosis of this pathology; and 3) the determination of ADA in an area with high prevalence of the disease was a reliable and unexpensive diagnostic method.