Title: Impact of BCG Vaccination Status on Sputum Conversion Rate in New Sputum Positive cases of Pulmonary Tuberculosis
Authors: Priyam Goswami, Basanta Laskar, Jayanta Kumar Nath
DOI: http://dx.doi.org/10.18535/jmscr/v4i8.40
Objectives: Sputum conversion rates (SCR) at the end of intensive phase of treatment of pulmonary tuberculosis varies and knowledge of factors involved is, inadequate. It has been reported that presence of a BCG scar was associated with greater rate of sputum conversion at the end of intensive phase (IP) of treatment. Hence, this study was undertaken with aim of studying the relationship between BCG vaccination status and sputum conversion rate in pulmonary tuberculosis (PTB) patients. Materials And Methods: This was a hospital based observational study done at Assam Medical College and Hospital, Dibrugarh from July 2012 to June 2013. All new sputum smear positive (SSP-PTB) patients were put on antitubercular therapy under DOTS and followed up with repeat sputum microscopy at the end of intensive phase. A comparative study on the outcome was done between BCG scar positive and negative cases and statistical analysis done. Results: All the 102 new SSP-PTB cases successfully completed intensive phase treatment under DOTS. Out of these 19 patients had to be put on extended IP of 1 month. BCG scar was present in 64.17% cases and absent in 35.29%. Overall, 81.37% of new sputum positive (NSP) cases converted at the end of second month IP on DOTS. In BCG scar present group, sputum conversion rate (SCR) was 90.90% whereas in scar absent group it was 63.89%, showing a significant ‘p’ value of 0.0013.In the extended IP group 94.48% cases with scar converted, while 22.22% without BCG scar remained non-converted with a significant ‘p’ value of 0.0009. Conclusion: New SSP-PTB patients with evidence of previous BCG vaccination, show a significantly better sputum conversion rate at the end of intensive phase of DOTS. Keywords: Pulmonary tuberculosis, BCG vaccine, Sputum conversion rate. 1. Kidola Jeremiah, George Pray God Daniel Faurholt-Jepsen et al: BCG vaccination status may predict sputum conversion in patients with pulmonary tuberculosis; a new consideration of old vaccine BMJI Journal, Issue1, 2011 2. WHO Global TB Report,2010 Update 3. World Health Organization, Treatment of Tuberculosis, guidelines for national programme, Fourth Edition,2010, WHO 4. Rieder, H.L. Sputum smear conversion during directly observed treatment for Tuberculosis. Tubercle. Lung. Dis. 1996; 77: 124-129. 5. C.Kuaban, R.Bame, L. Mouangue, S.Djella and C. Yomgni on East African Medical Journal Vol.86 No.5 May 2009 6. Sterne JA, Rodrigues LC, Guedes IN. Does the efficacy of BCG decline with time since vaccination? Int J Tuber Lung Dis. 1998;2:200-7 7. Telzak EE ,Fazal BA ,Pollard CL et al: factors influencing sputum smear and culture conversion time among patients with new case pulmonary tuberculosis. 8. Gular M, Unsal E, Dursun B, et al. factors influencing sputum smear and culture conversion time among patients with new case pulmonary tuberculosis. Int J Clin Pract 2007;61:231-5. 9. Gopi PG, Chandrasekaran V, Subramani R, et al. Association of conversion and cure with initial smear grading among new smearcase pulmonary tuberculosis patients treated with category 1 regimen. India J Med Res 2006;123:807-14. 10. Banu Rekha VV. Balasubramanian R, Swaminathan S, et al. Sputum conversion at the end of intensive phase of category-1 regimen in the treatment of pulmonary tuberculosis patients with diabetes mellitus or HIV infection: an analysis of risk factors. Indian J Med Res 2007;126:452-8 11. Tanzanian/BMRC collective study 1985, Tuberculosis in Tanzania –A national survey of newly notified cases. Tubercle 66:161 12. Marcelo fouad Rabahi, Adriana Batista Rodriquez, Fernanda queiroz De Mello, Joaquim Caetano de Almeida Netto Afranio Lineo, Kritski, Clementito, Filho University, Federal University of Rio De Janerio, RJ, 1998. 13. Colditz GA, Brewer, TF, Berkey CS, Wilson ME, Burdick E, Fineberg HV, et al. Efficacy of BCG vaccine in the prevention of tuberculosis. Meta-analysis of the published literature. JAMA. 1994;271:698-702. 14. Tiwari S, Kumar ,Kapoor SK (2012) :National Tuberculosis Institute (DBT); Relation of SCR and pretreatment sputum smearing grading. 15. Comstock GW, Edwards PQ. An American view of BCG vaccination, illustrated by results of a controlled trial in Puerto Rico. Scand J Resp Dis. 1972;53:207-17. Abstract
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