By Aggarwal, Deepak Mohapatra, P R; Rekha, V V Banu; Balasubramanian, R; Swaminathan, S; Ramachandran, R; Rahman, F; Sundaram, V; Thyagarajan, K; Selvakumar, N; Adhilakshmi, A R; Iliayas, S; Narayanan, P R
Sir, Banu Rekha and colleagues’ in their study found that at the end of intensive phase of tuberculosis treatment among sputum positive cases, the smear conversion rates were 58, 61, 62 per cent and culture conversion 86, 88 and 92 per cent respectively. Also, the patients with HIV infection or diabetes had marginally better conversion rate than pulmonary tuberculosis patients without any co- morbidity. According to Revised National Tuberculosis Control Programme (RNTCP), the minimum duration of treatment to assess outcome of pulmonary tuberculosis patients is 6 months. However, the authors’ have discussed the smear conversion rate after two months (intensive phase) without mentioning treatment outcome at the completion of continuation phase (after 6 months of initiation of therapy).
This sputum conversion at the end of intensive phase can be attributed to fall and rise phenomenon2, where within weeks of starting anti-tubercular treatment there is a decrease in number of drug susceptible mycobacteria and sputum smear may turn negative. But, at the same time, resistant bacilli are not affected and they continue to multiply. As a result, after a certain time, bacillary content of the sputum rises again and sputum smear becomes positive for acid fast bacilli. Due to occurrence of this phenomenon, sputum conversion at 2 months is not an ideal parameter to predict and compare treatment outcomes among pulmonary tuberculosis patients with or without comorbid conditions.
It will be of immense help if the authors can provide the final outcome of the study after completion of treatment among the patients whose data are available. Sputum conversion at 6 months and after completion of therapy (not at 2 months) can substantially validate the current policy of RNTCP to treat all pulmonary tuberculosis patients, with or without co-morbidities, with category- I regimen.
Deepak Aggarwal & P.R. Mohapatra*
Department of Pulmonary Medicine
Government Medical College & Hospital
Sector 32
Chandigarh 160 030, India
* For correspondence:
References
1. Banu Rekha VV, Balasubramanian R, Swaminathan S, Ramachandran R, Rahman F, Sundaram V, 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.
2. Crofton J, Mitchison DA. Streptomycin resistance in pulmonary tuberculosis. Br Med J 1948; 2 : 1009-15.
Authors’ response
Sir,
This publication was an interim report on the first indicator of the efficacy of the regimen1. At the Tuberculosis Research Centre, Chennai, all patients are followed up with monthly smear and culture examination during treatment. The status of the pulmonary tuberculosis with associated diabetes mellitus or HIV infection at the end of treatment have shown that at the end of treatment smear conversion was 95 and 85 per cent for patients with diabetes mellitus or HIV infection, respectively23. Thus, the conversion observed at the end of intensive phase was a true indicator and the response was similar at the end of treatment in these groups. For patients receiving category-I regimen in the RNTCP, smear conversion at the end of intensive phase is emphasized as an important early predictor of treatment success. In this background, it is essential to evaluate associated co-morbid conditions like HIV infection and diabetes mellitus among TB patients that are likely to influence smear conversion. We agree that the sputum conversion at 6 months can substantially validate the current RNTCP policy of treatment all pulmonary tuberculosis patients with or without co-morbid conditions with category-I regimen. We are planning to publish the comparison of results of these groups of patients at the end of treatment and relapse up to 6-month of follow up.
V.V. Banu Rekha, R. Balasubramanian
S. Swaminathan, R. Ramachandran*, F. Rahman
V. Sundaram, K. Thyagarajan, N. Selvakumar
A.R. Adhilakshmi, S. Iliayas & P.R. Narayanan
Tuberculosis Research Centre (ICMR)
Mayor V.R. Ramanathan Road, Chetput
Chennai 600 031, India
* For correspondence:
References
1. Banu Rekha VV, Balasubramanian R, Swaminathan S, Ramachandran R, Rahman F, Sundaram V, 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.
2. Balasubramanian R, Ramanathan U, Thiagarajan K, Ramachandran R, Rajaram K, Bhaskar D, et al. Evaluation of an intermittent six- month regimen in new pulmonary tuberculosis patients with diabetes mellitus. Indian J Tuberc 2007; 54 : 168-76.
3. Swaminathan S, Sangeetha M, Arun Kumar N, Menon PA, Thomas B, Shibi K, et al. Pulmonary tuberculosis in HIV positive individuals: Preliminary report on clinical features and response to treatment. Indian J Tuberc 2002; 49 : 189-93.
Copyright Indian Council of Medical Research Apr 2008
(c) 2008 Indian Journal of Medical Research. Provided by ProQuest LLC. All rights Reserved.
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