Comparative Evaluation of the Rapid Slide Culture and Microscopy with the Conventional Culture Method in the Diagnosis of Pulmonary Tuberculosis 192-194
No. 12 Mount View Enclave, Bettahalasur cross
Bangalore North â€“ 562157, Karnataka, India.
Introduction: Tuberculosis (TB) is a global health problem. An early diagnosis and an effective treatment are essential to prevent the spread of infection and to reduce the disease burden. Though the causative bacterium for this disease was discovered in the eighteenth century, its diagnosis in the twenty-first century is still a dogma.
Objectives: To compare of the rapid slide culture (RSC) method with the growth on Lowenstein Jensen (LJ) media and to know the sensitivity and specificity of the rapid slide culture method and the acid fast smear examination in comparison with the growth on the L J media.
Materials and Methods: One early morning sputum sample was collected from 220 clinically suspected pulmonary tuberculosis cases. All the samples were subjected to three tests: 1. Zeihl Neelsen Staining 2. Rapid slide culture and 3. Culture on Lowenstein Jensen media and the results were compared.
Results: Of the total 220 sputum samples which were tested by all the three methods, 51 samples (23.18 %) were found to be smear positive, 75 (34.09%) were found to be positive by the RSC method, 81 (36.81%) were found to be positive by the LJ culture method and 38(17.27%) samples were found to be positive by all the three methods and 93 (42.27%) samples were found to be positive by any one method. 127 (57.72%) samples were negative by all the three tests The sensitivity of RSC in comparison with the LJ culture was 88.88% with a specificity of 97.8%, whereas the smear showed a sensitivity of 49.4 % and a specificity of 92.1%.
Discussion: The RSC method is rapid, sensitive and more specific than microscopy. Hence, this method can be adopted by any simple laboratory for the diagnosis of tuberculosis.