title: Diagnosing tuberculosis in a resource-poor setting: the value of a trial of antibiotics.
abstract: Diagnosis of smear-negative but culture-positive pulmonary tuberculosis in resource-poor settings is difficult. To determine the value of assessing response to a trial of antibiotics in the identification of patients with positive cultures but negative Ziehl-Neelsen (ZN) smears, we compared clinicians' diagnoses with culture in 334 consecutive adults with suspected tuberculosis in rural South Africa; 142 patients (43%) had culture-positive pulmonary tuberculosis. Diagnosis by ZN smear alone was insensitive (61%) but highly specific (94%). Only half of the smear-negative but culture-positive cases were correctly identified by failing to respond to a broad spectrum antibiotic. The remainder responded to therapy and were discharged. Diagnostic sensitivity therefore increased to 80%, but specificity fell to 78%. A more rigorous algorithm may improve diagnosis of smear-negative pulmonary tuberculosis in resource-poor settings.
authors.affiliation: Centre for Epidemiological Research in Southern Africa, South African Medical Research Council, Hlabisa, South Africa.
authors.forename: D
authors.initials: D
authors.lastname: Wilkinson
authors.forename: K M
authors.initials: KM
authors.lastname: De Cock
authors.forename: A W
authors.initials: AW
authors.lastname: Sturm
mesh_terms: D000328:Adult; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D006801:Humans; D008507:Medically Underserved Area; D012680:Sensitivity and Specificity; D013019:South Africa; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000188:drug therapy
chemical_list: D000904:Antibiotics, Antitubercular