title: Comparative study of Smear Microscopy, Rapid Slide Culture, and Lowenstein - Jensen culture in cases of pulmonary tuberculosis in a tertiary care hospital.
abstract: BACKGROUND
  Tuberculosis (TB), a dreadful disease known to mankind continues to be a problem in a developing country like India. The incidence of people getting infected with TB is on the rise due to compounding factors like coinfection with the human immunodefiency virus and multidrug-resistant strains. There is a definitive need for early diagnosis and treatment of TB to curb transmission of the infection. Direct smear microscopy, though cheap and rapid, lacks sensitivity. Isolation of Mycobacterium tuberculosis in culture requires a long time, because of which there is a need for a rapid method which has good sensitivity and specificity for the detection of M. tuberculosis. The present study was undertaken to determine the test which diagnoses TB rapidly and to compare the sensitivity of smear microscopy, concentration method, rapid slide culture, and Lowenstein - Jensen (LJ) culture.
  
  
  METHODS
  Sputum samples of 200 patients were subjected to direct smear and concentration by modified Petroff's method. The concentrated sputum was also taken for slide culture using human blood medium and inoculated on LJ media.
  
  
  RESULTS
  LJ culture was positive in 47 (23.5%) cases, of which three were nontubercular mycobacteria. Using LJ culture as the standard method, the sensitivity of direct smear, concentration method, and rapid slide culture method was 68, 83, and 89%, respectively, and specificity was 100% in all the three tests.
  
  
  CONCLUSIONS
  Rapid slide culture showed good sensitivity which was comparable to and next in efficacy to LJ culture and this technique can be adopted in the Revised National Tuberculosis Control Program (RNTCP) as it is a rapid, cheap, sensitive, and specific method.
authors.affiliation: Department of Microbiology, Basaveshwara Medical college, Chitradurga, India.
authors.forename: Ravish Kumar
authors.initials: RK
authors.lastname: Muddaiah
authors.affiliation: Department of Microbiology, Basaveshwara Medical college, Chitradurga, India.
authors.forename: Pratibha Malini
authors.initials: PM
authors.lastname: James
authors.affiliation: Kempegowda institute of medical sciences, Banashankari 2 stage, Bangalore, India.
authors.forename: Ravikumar Kadahalli
authors.initials: RK
authors.lastname: Lingegowda
keywords: Direct microscopy; Lowenstein - Jensen media; pulmonary tuberculosis; rapid slide culture