Molecular typing of Mycobacterium tuberculosis isolates from different parts of India based on IS6110 element polymorphism using RFLP analysis.

BACKGROUND & OBJECTIVE: IS 6110 based typing remains the internationally accepted standard and continues to provide new insights into the epidemiology of Mycobacterium tuberculosis. The aim of the study was to characterize M. tuberculosis isolates obtained from different parts of India based on IS6110 element polymorphism using restriction fragment length polymorphism (RFLP) analysis. METHODS: RFLP was analyzed among 308 isolates of M. tuberculosis deposited in the Mycobacterial Repository Centre, Agra, from different parts of India. DNAs isolated from these strains were restricted with Pvu II, transferred on to nylon membrane and hybridized with a PCR amplified DIG-labeled 245 bp IS6110 probe. RESULTS: Based on the copy number, M. tuberculosis isolates were classified into four groups, (i) lacking IS6110 element; (ii) low copy number (1-2); (iii) intermediate copy number (3-5); and (iv) high copy number (6-19). Copy number higher than 19 however was not observed in any of the isolates studied. At the national level, 56 per cent of the isolates showed high copy number of IS6110, 13 per cent showed intermediate copy number, 20 per cent showed low copy number, whereas 11 per cent isolates lacked IS6110 element. At the regional level, there was not much difference in the RFLP profiles of isolates (IS6110 copy numbers/patterns) from different parts of the country. INTERPRETATION & CONCLUSION: IS6110 DNA based fingerprinting could be a potentially useful tool for investigating the epidemiology of tuberculosis in India.

Treatment of tuberculous pleural effusion patients and their satisfaction with DOTS - 1½ year follow up.

Background: Under the Revised National Tuberculosis Control Programme, patients who are sputum negative after 3 smear examinations are subjected to radiological examination after they fail to respond to a course of antibiotics for a period of two weeks. Those showing radiological evidence of pleural effusion are examined physically and investigated further by tuberculin testing and diagnostic aspiration. Those confirmed to be suffering from tuberculous pleural effusion by naked eye examination, biochemical tests and cytology of pleural fluid are given a fixed schedule of drugs. The treatment is stopped after six or eight months as per category, and outcome is reported as “Treatment Completed”. Many a time, patients question the validity of stopping treatment without radiological examination. Physicians treating are also at times not confident themselves and often fail to reassure such patients. Presence of residual symptoms in such patients before stopping treatment creates further uneasiness among the treating physicians. Methodology and Results: A study carried out among 58 patients of TB pleural effusion, of which 36 (62.1%) could be followed for a period of 1½ years, revealed that 63.9% were satisfied with the DOTS policy of stopping treatment without x-ray at the end of treatment whereas 36.1% expressed dissatisfaction with this policy. As many as 16.7% even got their x-rays elsewhere before stoppage of treatment, for their own satisfaction. Conclusion: The 1½ year follow up revealed only one case of relapse i.e. a relapse rate of 2.8% after DOTS therapy. Almost all (97.2%) were, however, satisfied with the medicines dispensed under DOTS.

Tuberculosis in the elderly and their treatment outcome under DOTS.

Summary: A retrospective study of the profile and treatment outcome in the elderly TB patients taking DOTS was carried out in an urban TB clinic of Delhi. Out of 2118 tuberculosis patients treated between 1999-2001, a total of 238 (11.4%) patients were over 50 years of age and of these 45(2.2%) were over 65 years of age. A total of 78.6% of the 283 TB patients of all the categories included in the study had a successful outcome (cure/ completion). The overall case fatality, default and failure rates among the TB patients over 50 years were found to be 7.1%, 8.8% and 4.6%, respectively, despite directly observed treatment being given under RNTCP. The case fatality rate was significantly higher (15.6%) in the age group >65 years as compared to patients between 50-65 years (5.2%). The failure rate was significantly higher (13.3%) in the age group >65 years than among patients in the 50-65 years age-group (2.6%). This emphasizes the need for intensive motivation and stringent monitoring among tuberculosis patients over 65 years of age.