Bleached smear microscopy provides higher yield in diagnosing pulmonary tuberculosis
Keywords:Bleach concentration microscopy, Pulmonary tuberculosis, Direct microscopy, Diagnostic yield
Background: Tuberculosis (TB) remains one of the major deadliest communicable diseases throughout the world. Worldwide, 9.6 million people are estimated to have fallen ill with TB in 2014, India accounts for 23% of total global cases. The study evaluated the performance of direct sputum smear versus bleach concentration smear in diagnosis of pulmonary tuberculosis.
Methods: Patients more than 10 years of age who presented with history of cough for >2 weeks duration were included. One spot specimen and another early morning specimen were collected on two consecutive days. All the sputum smears prepared from direct and bleach concentration were examined under microscope after Ziehl-Neelsen staining.
Results: A total of 290 specimens were examined by microscopy, among which 128/290 (44.1%) were positive on direct smear, additionally 72/290 (24.8%) were positive on bleached smear, and therefore the gain% in the diagnostic yield was 24.8% (P<0.0001). The order of yield was mucoid specimen (28.6%)>blood stained (26.74%) >purulent specimen (20.8%) (p>0.05) and early morning specimens (33%)>spot specimen (22%) (p>0.05), However, these findings were not statistically significant.
Conclusion: Microscopic examination of bleached smear examination has shown a significant yield over conventional method in the detection of pulmonary Tuberculosis. Such superiority was independent of type of sputum and timing of collection of sputum.
WHO. 20th edition Global tuberculosis report WHO Geneva. 2015.
Apers L, Wijarajah C, Mutsvangwa J, Chigara N, Mason P, van der Stuyft P. Accuracy of routine diagnosis of pulmonary tuberculosis in an area of high HIV prevalence. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease. 2004;8(8):945-51.
Srikanth P, Kamesh S, Daley P. Bleach optimization of sputum smear microscopy for pulmonary tuberculosis. The Indian journal of tuberculosis. 2009;56(4):174-84.
Angeby KA, Hoffner SE, Diwan VK. Should the 'bleach microscopy method' be recommended for improved case detection of tuberculosis? Literature review and key person analysis. The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease. 2004;8(7):806-15.
Aung WW, Nyein MM, Ti T, Maung W. Improved method of direct microscopy for detection of acid-fast bacilli in sputum. The Southeast Asian journal of tropical medicine and public health. 2001;32(2):390-3.
Mutha A, Tiwari S, Khubnani H, Mall S. Application of bleach method to improve sputum smear microscopy for the diagnosis of pulmonary tuberculosis. Indian journal of pathology and microbiology. 2005;48(4):513-7.
Ongkhammy S, Amstutz V, Barennes H, Buisson Y. The bleach method improves the detection of pulmonary tuberculosis in Laos. The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease. 2009;13(9):1124-9.
Hepple P, Nguele P, Greig J, Bonnet M, Sizaire V. Direct microscopy versus sputum cytology analysis and bleach sedimentation for diagnosis of tuberculosis: a prospective diagnostic study. BMC Infectious Diseases. 2010;10:276.
Khan MS, Dar O, Sismanidis C, Shah K, Godfrey-Faussett P. Improvement of tuberculosis case detection and reduction of discrepancies between men and women by simple sputum-submission instructions: a pragmatic randomised controlled trial. The Lancet. 2007;369(9577):1955-60.
Technical and operational guidelines for tuberculosis control, Revised National Tuberculosis Control Programme. New Delhi: Central Tuberculosis Division, Directorate General of Health Services, Ministry of Health and Family Welfare, Government of India. 2005.
Gebre N, Karlsson U, Jönsson G, Macaden R, Wolde A, Assefa A, et al. Improved microscopical diagnosis of pulmonary tuberculosis in developing countries. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1995;89(2):191-3.
Kashyap B, Jhamb R, Mishra PK, Kaur IR. Validation of bleach optimization for smear microscopy in pulmonary tuberculosis in resource-constrained settings. Journal of pharmaceutical and biomedical sciences. 2012;24(24):21-5.
Iqbal S, Amin D, Mumtaz A, Shabir I. Significance of appropriate sampling in the diagnosis of tuberculosis (TB)-a comparison of different techniques. Biomedica. 2010;26:39-44.
Pingle P, Apte, P. and Trivedi, R. Evaluation of Increased Sensitivity of Morning Bleach Sample for Detection of Acid Fast Bacilli in Pulmonary Samples. Journal of Tuberculosis Research. 2014;2:119-24.
Anagaw B, Mulu A, Abate E, Belay T, Gelaw A, Alemayehu M, et al. Improved detection of acid-fast bacilli in sputum by the bleach-concentration techinique at Gondar University Teaching Hospital, northwest Ethiopia. Ethiopian medical journal. 2012;50(4):349-54.
Mindolli PB, Salmani MP, Parandekar PK. Improved diagnosis of pulmonary tuberculosis using bleach microscopy method. Journal of clinical and diagnostic research: JCDR. 2013;7(7):1336.
Makunde WH, Makunde, R.A., Kamugisha, L.M., Mgema, S.G. and Liwa, A. Improved Microscopy Diagnosis of Pulmonary Tuberculosis Using Sodium Hypochlorite Concentration Technique In Tanga, Tanzania. Tanzania Health Research Bulletin. 2007;9:87-93.