Accuracy of routine diagnosis of pulmonary tuberculosis in an area of high HIV prevalence. 
Gweru Provincial Hospital, Zimbabwe.  To evaluate the accuracy of the diagnosis of pulmonary tuberculosis (PTB) in routine circumstances.  Prospective cohort study of routinely diagnosed PTB patients between September 2000 and September 2001.  Of 300 patients started on treatment, 161 (53.7%) were positive on direct microscopy.  Of the 139 sputum-negative patients, 51 (36.7%) were positive after concentration of specimens, an additional 30 (21.6%) were positive on culture only and 58 (19.3% of the total) were negative for all laboratory investigations.  There was no difference in sex, human immunodeficiency virus (HIV) serostatus or treatment outcome between the culture-positive and culture-negative presumed PTB patients.  Sputum-negative patients had an increased risk of dying during treatment (RR 2.39, P = 0.015).  The laboratory findings reveal that PTB could be confirmed in more than 80% of patients put on treatment in this setting.  The treatment outcomes of the remainder did not differ from those in patients with microbiologically confirmed PTB.  In a high HIV-prevalent area, clinicians rightly consider the results of the sputum microscopy test as only one element in the decision making process to put a patient on TB treatment.