Prevalence of multidrug-resistant tuberculosis among Category II pulmonary tuberculosis patients.

Background & objectives: Multidrug-resistant tuberculosis (MDR-TB) has emerged as a significant global health concern. The most important risk factor for the development of MDR-TB is previous anti-tuberculosis therapy. Category II pulmonary TB includes those patients who had failed previous TB treatment, relapsed after treatment, or defaulted during previous treatment. We carried out this study to ascertain the prevalence of MDR-TB among category II pulmonary TB patients. Methods: This was a cross-sectional, descriptive study involving category II pulmonary TB patients diagnosed between 2005 and 2008. All sputum-positive category II TB cases were subjected to mycobacterial culture and drug-susceptibility testing (DST). MDR-TB was defined as TB caused by bacilli showing resistance to at least isoniazid and rifampicin. Results: A total of 196 cases of sputum-positive category II pulmonary tuberculosis patients were included. Of these, 40 patients (20.4%) had MDR-TB. The mean age of MDR-TB patients was 33.25 ± 12.04 yr; 9 patients (22.5%) were female. Thirty six patients showed resistance to rifampicin and isoniazid; while 4 patients showed resistance to rifampicin, isoniazid and streptomycin. The prevalence of MDR-TB among category-II pulmonary tuberculosis patients was 20.4 per cent. Interpretation & conclusions : The prevalence of MDR-TB in category II TB patients was significant. However, nation-wide and State-wide representative data on prevalence of MDR-TB are lacking. We stress the importance of continuous monitoring of drug resistance trends, in order to assess the efficacy of current interventions and their impact on the TB epidemic.

Efficacy of repeat sputum examination in RNTCP.

BACKGROUND: The guidelines of repeat sputum smear examination in initial smear negative patients (ISN), who also fail the antibiotic trial of three samples have been incorporated in the RNTCP diagnostic algorithm in India in 2005. This study was conducted to assess the utility of repeat sputum smear examination in symptomatic initial smear negative patients to detect new smear positives in the state of Delhi. MATERIAL AND METHODS: The monthly records of the laboratory abstracts for the six quarters for all the 24 districts of Delhi were analysed w.e.f. first of January 2006 to 30th June 2007. RESULTS: A total of 243,244 TB suspects were examined for diagnosis during the six quarters w.e.f. January 2006. Of these, 37,666 were found positive on sputum smear microscopy giving a positivity rate of 15.4%. During the same period, a total of 2,195 (1% of ISN ) TB suspects underwent repeat sputum examination, of which 272 were found positive giving a mean positivity of 12.3%. CONCLUSION: A significant number of apparently smear negative TB cases may in fact be smear positive due to various reasons and can be detected by a simple repeat sputum examination. Yield of sputum positive cases in sputum reexamination is almost the same as in initial sputum examination i.e. 10-15%. Therefore, the policy of repeat sputum examination in symptomatic initial sputum negative cases failing the antibiotic trial should be meticulously followed as advocated in the RNTCP diagnostic algorithm.

Outcome of multi-drug resistant tuberculosis cases treated by individualized regimens at a tertiary level clinic.

AIM: To determine the clinical, radiological and drug resistance profile as well as the factors associated with treatment outcome of Multi-Drug Resistant Tuberculosis (MDR-TB). MATERIAL AND METHODS: All newly diagnosed patients with pulmonary MDR-TB from August 2002 to December 2004 enrolled at New Delhi Tuberculosis Centre, were included in the study. They were followed up clinically, radiologically and bacteriologically by sputum smear, culture and Drug Susceptibility Testing (DST) at regular intervals. According to their DST pattern and previous history of Anti-Tubercular Treatment (ATT), individualized treatment regimens were tailored for each patient. RESULTS: Out of total 27 bacteriologically proven cases of MDR-TB included in this study, 19 were males (mean age and weight 38.5 years and 52.6 kgs, respectively) and eight females (mean age and weight 34.3 years and 40.7 kgs, respectively). A majority (18) were residents of Delhi and the rest hailed from different parts of North India. All of them had a history of previous treatment ranging from six to 34 months. Cavity on chest X-rays was seen in 81%, while 44% showed extensive involvement. The patients received at least four "second line drugs" during their treatment with a mean of 6.2 anti-tubercular drugs during their intensive phase. Of the 27 patients, 13 were cured, 10 defaulted, one died, one is still on treatment and two were referred for surgery. Radiological improvement was observed in two third of cases and chest X-ray of two patients showed a complete resolution. Six predictors were identified for successful outcome of MDR-TB. They include weight gain at six months, culture conversion, radiological improvement during treatment, disease with M. tuberculosis strains exhibiting resistance to less than or up to three anti-tubercular drugs, use of less than or up to three second line drugs in treatment and no change of regimen during treatment. CONCLUSION: Default from treatment was observed to be a major challenge in the treatment of MDR-TB due to long duration and expense of ATT.

Prevalence of initial drug resistance to M. tuberculosis in new sputum positive RNTCP patients.

There is an increased prevalence of drug resistant M. tuberculosis strains and of these, multi drug resistant organisms are of particular concern. With the implementation of Revised National Tuberculosis Control Programme (RNTCP) allover the state of Delhi, Initial drug resistance (IDR) to Isoniazid and Rifampicin assumes great importance and needs to be monitored on a regular basis. We undertook to study the IDR against the first line essential drugs i.e. Isoniazid (H), Rifampicin (R), Ethambutol (E) and Streptomycin (S) from April 1999 to March 2000 in newly diagnosed sputum positive cases of pulmonary tuberculosis attending TB clinics under RNTCP in Delhi. A total of 157 consecutive new smear positive patients attending TB clinics under RNTCP were taken into the study. All sputum samples were subjected to culture and drug sensitivity tests on LJ medium after decontamination of samples by Petroff's method. Resistance was expressed as the percentage of colonies that grow on critical concentration of the drugs. To determine the proportion of resistance, the number of colonies on the control and the number of colonies on the drug medium were determined. A total of 94.77% samples were sensitive to the four first line essential drugs and IDR to any drug was 5.22%. The resistance to Rifampicin alone was nil but the resistance to Isoniazid alone was 2.24%. Combined resistance to both Rifampicin and Isoniazid was 2.98 %. The incidence of resistance to first line drugs in tuberculosis is not very high among new sputum positive patients attending TB clinics under RNTCP.

Hypomagnesemia and clinical implications in children and neonates.

The prevalence of hypomagnesemia was studied in neonates and children. The specimens were selected randomly from those submitted to the clinical chemical laboratory for blood test. A serum magnesium concentration less than 0.74 mmol/L was considered hypomagnesemic. A total serum magnesium determinations of 910 patients showed that 188 (21.7% prevalence rate) patients contained low serum magnesium levels. Frequently encountered hypomagnesemia was found among neonates with clinical conditions as diarrhea 41 (21.8%), premature births 24 (12.8%), neonatal hepatitis 20 (10.6%) and respiratory distress syndrome 5 (2.7%). In children the clinical conditions most frequently encountered with low serum magnesium were seizure 30 (16%), renal disease 26 (13.8%), metabolic acidosis 18 (9.6%), ideopathic apnea 14 (7.4%) and tachycardia 10 (5.3%). The statistical analysis of low serum magnesium values of patients in various clinical groups showed a significant difference (p < 0.0001) upon using homogeneity of variances but this was insignificant with the application of Kruskal-Wallis 1-Way ANOVA since Chi-square = 12.5748.