Assessment of Sputum Preparation Techniques for Diagnosis of Pulmonary Tuberculosis in Khartoum State

Abstract

This study was carried out in Khartoum State during the period between May 2013 to February 2014, aimed to evaluate twotechniques smear preparation methods for Ziehl–Neelsen (ZN) staining for acid fast bacilli (AFB) in patients with signs and symptoms of tuberculosis and compared with PCR as reference method. Ninety sputum samples were collected from different TB centers in Khartoum State including Abu Anga Hospital, the National Reference Tuberculosis Laboratory, and Elsha’ab Teaching Hospital. The results revealed that from the total of 33 positive samples by PCR, 8 specimens were found to be positive in direct, 24 positive with concentrated smear microscopy. The study concluded that use of the concentrated method for preparing smears for AFB microscopy increases sensitivity without a loss of specificity in identifying positive TB cases, which proved to be a better method for diagnosis of the disease.