The efficiency of methods of diagnosing pulmonary tuberculosis: An investigation in a chest clinic in algiers

During a four month period 529 patients with respiratory symptoms attended a chest clinic in Algiers. Questioning, sputum examinations, chest x-rays and tuberculin tests were done in all. The results were used to evaluate the relative efficiency of these routine diagnostic measures, alone and in combination. Seventy-one patients (13%) had sputum positive on microscopy (55) or on culture only (16). From the single specimen of sputum collected at the first visit 45 cases (63% of the discovered cases), were detected. If sputum had been examined from only the 222 who complained of haemoptysis, 73% of the 45 cases would have been detected by examining only 42% of the number of smears needed to detect all cases. If sputum had been examined from only those with tuberculin reactions greater than 5 mm. diameter, 91% of the microscopy-positive cases would have been detected with a saving of 20% of sputum examinations. Ninety of the 529 patients had x-rays interpreted as 'active tuberculosis'. A single specimen of sputum from these 90 patients detected all the 45 microscopy-positive patients-less than 20% of the total smear examinations needed if all patients had sputum examined. In a hypothetical clinic with only microscopy facilities 57% of sputum-positive patients could be detected by examining up to four specimens from only those complaining of haemoptysis-five patients for one positive. If an x-ray apparatus were available 76% could be detected by examining sputum from those with chest x-rays reported 'active tuberculosis'-less than two patients for one positive. If, in addition, culture facilities were available, 90% could be detected by examining sputum only from the radiographically, 'active tuberculosis' group-again less than two patients for one positive.