Productivity, water use efficiency and economics of system of rice intensification (SRI) in Nichabanadhi sub basin of southern Tamil Nadu

Four hundred and sixteen on-farm demonstrations on system of rice intensification (SRI) were carried out in 350 hectares of farmer’s fields in Sankarankovil, Vasudevanallur and Kuruvikulam blocks of Tirunelveli district of Tamil Nadu from 2008-09 to 2010-11 under Tamil Nadu – Irrigated Agriculture Modernization and Water Bodies Restoration and Management (TN-IAMWARM) project. Two methods viz., SRI and conventional were compared. The results revealed that the adoption of SRI favorable influenced yield attributes and yield of rice. The maximum grain yield (8222 kg ha-1) obtained from SRI which was higher than conventional method (6534 kg ha-1). Higher grain yield coupled with substantial water saving to the tune of 37.1 per cent resulted in higher water use efficiency of rice under SRI method. The best net income ( Rs. 50, 587) and benefit: cost ratio (3.64) were also associated with SRI than conventional method of rice cultivation. The cost of cultivation was comparatively lesser in SRI which re-sulted in gaining an additional income of Rs. 8080 ha-1 as compared to conventional method of rice cultivation. The system of rice intensification (SRI) proved its benefits in this basin

Transportation of lymph node biopsy specimens in selective Kirchner’s liquid medium for culture of tubercle bacilli

Lymph node biopsy specimens, obtained from 297 paediatric and adult patients with tuberculous lymphadenitis at Madurai, were transported in selective Kirchner’s liquid medium (KL-T) to the Tuberculosis Research Centre, Madras and processed for culture. Mycobucterium tuberculosis was isolated from 201 (68%) specimens. Of the 192 specimens received within 4 days of resection, 134 (69.8%) yielded M. tuberculosis on culture and of the 105 specimens received after 5 days, 67 (63.8%) were culture positive; the difference was not statistically significant. By incubating KL-T alone further, after removing the gland for processing, it was found that mere contact with the excised node during transportation was enough to retrieve 77 (38.3%) of the total of 201 positive isolates obtained, the delay did not affect the culture positivity rate. Thus, lymph node specimens for culture of tubercle bacilli can be stored in the refrigerator for up to 15 days and transported in KL-T at ambient temperature for 18-20 h without any loss in culture positivity

Vancomycin for controlling contamination of selective Kirchner’s liquid medium in the culture of gastric lavage for tubercle bacilli

Gastric lavage (GL) was collected for culture of tubercle bacilli from children too young to expectorate sputum. The selective Kirchner’s liquid medium (SKLM), routinely used as one of the media for culture of all extrapulmonary specimens, was found to often get contaminated when cultured with GL. We have shown that vancomycin at a concentration of 10 mg/l successfully reduced the contamination from about 60 to 20 per cent, and enhanced the Isolation rate of tubercle bacilli from 3 to 6 per cent. Decontamination of the liquid culture before subculture on solid medium also helped to reduce the contamination rate. Vancomycin was found to be an effective selective drug for use In the Kirchner’s liquid medium for culture of tubercle bacilli

Seroprevalence of human immunodeficiency virus (HIV) infection among tuberculosis patients in Tamil Nadu

Background & objectives: The dual epidemic of HIV and tuberculosis is a cause for concern in those countries where these two infections are prevalent in epidemic proportions. We undertook a survey at two sites in North Arcot district of Tamil Nadu in 1992-1993, to know the seroprevalence of HIV infection among tuberculosis patients. The objective of this study was to re-examine the prevalence of HIV infection among tuberculosis patients in a repeat survey. Methods: The study was undertaken in four centres: District Tuberculosis Centre (DTC), Vellore, Tuberculosis Sanatorium, Pennathur (Vellore), District TB Centre (DTC), Kancheepuram and the Government Thiruvotteswarar Tuberculosis Hospital (GTTH), Chennai in the northern part of Tamil Nadu during 1997-1998. A total of 2361 newly diagnosed TB patients were registered in this study. HIV serology after pre-test counseling was done along with sputum examination for acid-fast bacillus by smear and culture for mycobacteria for all patients. Results: The overall HIV seroprevalence among TB patients was 4.7 per cent. The highest HIV seropositivity rate was found among patients aged 30-39 yr (10.6%). HIV seroprevalence showed a wide variation among the different centres ranging from 0.6. per cent in DTC, Kancheepuram to 9.4 per cent in Pennathur Sanatorium, Vellore. Sputum smear positivity was 88 per cent among the HIV-negative and 83 per cent among HIV-positive tuberculosis patients. Interpretation & conclusion: HIV infection is on the rise among TB patients in Tamil Nadu. Acid-fast smear microscopy is adequate for the diagnosis of pulmonary tuberculosis, and drug resistance among HIV positive patients is not a major problem at this point of time; hence antituberculosis regimens recommended by the Revised National Tuberculosis Control Program (RNTCP) can be used to treat HIV positive patients with tuberculosis

Simple Direct Drug Susceptibility Tests on Sputum Samples for Early Detection of Resistance in Tubercle Bacilli

Background: Direct sensitivity test either by sputum concentrate (DS) or swab method (DSM) set up along with the primary culture would avoid the delay of four or more weeks required for the indirect test. A comparison of these two methods against the standard indirect sensitivity method under routine laboratory conditions is necessary to prove their merit. Method: Smear positive sputum samples were aliquoted and sensitivity tests were set up by both the direct methods as also an indirect test set up from the primary culture of the same sample. Results: The agreement with the indirect test results for isoniazid (INH) ranged from 97-98% for the DS method and 93- 97% for the DSM method. The corresponding figures were 96-98% by the DS and 94-99% by the DSM method for rifampicin (R). The agreement was less satisfactory for ethambutol (Emb). Conclusion: This study showed that direct sensitivity tests such as DS and DSM methods can detect most of the cultures resistant to INH and R (MDR) from the time growth appears on the primary culture , even as early as the second week of setting up the tests

IgG antibodies against antigens of various mycobactrial species in children and in pre & Post BCG young adults

IgG antibodies against antigens of various mycobacteria were estimated by ELISA in serum samples collected (a) from 36 children (mean age 4.4 years) belonging to Koppur village in the south Indian BCG Trial area, (b) before and after BCG vaccination of 13 young individuals (mean age 16.5 years) belonging to Trivellore in the same area and (c) before and after BCG vaccination from 20 young British subjects (mean age 14.5 years). In the Koppur children, the antibody levels were highest against M. scrofulaceum and M. avium and lowest against M. bovis and M. tuberculosis H37Rv. In these children, there was no correlation between antibody levels and tuberculin reactivity. In the Trivellore subjects, antibody levels were highest against M. bovis BCG and M. gordonae, and lowest against PPD RT22 and M. terrae and none of the differences in the antibody levels against individual antigens between the preand post-BCG serum samples was statistically Significant (p >.05). The British subjects had the highest levels against M. tuberculosis 7219 while the lowest levels were against M. kansasii and M. tuberculosis 51; after BCG v a c c i n a t i o n t h e a n t i b o d y l e v e l s w e r e selectively increased against M. tuberculosis 7219, M. flavescens and M. gordornae (p <0.05)

First Panel Testing In SAARC Regional Networks of TB Reference Laboratories

Setting: South Asian Association for Regional Co-operation (SAARC) region with disproportionately high burden of TB in comparison of regional population. Objective: To establish a quality assurance on sputum smear microcopy in SAARC regional network of TB reference laboratories. Methods: Panel of slides were prepared and sent to national TB reference laboratories. The laboratory technician read the slides and sent report to SAARC TB center and report were analyzed. Results: Seven laboratories had no error of any type and one laboratory got two minor types of errors. Conclusion: Mot of the laboratories had excellent performance in panel testing

Use of Xpert MTB/RIF in Decentralized Public Health Settings and Its Effect on Pulmonary TB and DR-TB Case Finding in India

Background Xpert MTB/RIF, the first automated molecular test for tuberculosis, is transforming the diagnostic landscape in high-burden settings. This study assessed the impact of up-front Xpert MTB/RIF testing on detection of pulmonary tuberculosis (PTB) and rifampicin-resistant PTB (DR-TB) cases in India. Methods This demonstration study was implemented in 18 sub-district level TB programme units (TUs) in India in diverse geographic and demographic settings covering a population of 8.8 million. A baseline phase in 14 TUs captured programmatic baseline data, and an intervention phase in 18 TUs had Xpert MTB/RIF offered to all presumptive TB patients. We estimated changes in detection of TB and DR-TB, the former using binomial regression models to adjust for clustering and covariates. Results In the 14 study TUs, which participated in both phases, 10,675 and 70,556 presumptive TB patients were enrolled in the baseline and intervention phase, respectively, and 1,532 (14.4%) and 14,299 (20.3%) bacteriologically confirmed PTB cases were detected. The implementation of Xpert MTB/RIF was associated with increases in both notification rates of bacteriologically confirmed TB cases (adjusted incidence rate ratio [aIRR] 1.39; CI 1.18-1.64), and proportion of bacteriological confirmed TB cases among presumptive TB cases (adjusted risk ratio (aRR) 1.33; CI 1.6-1.52). Compared with the baseline strategy of selective drug-susceptibility testing only for PTB cases at high risk of drug-resistant TB, Xpert MTB/RIF implementation increased rifampicin resistant TB case detection by over fivefold. Among, 2765 rifampicin resistance cases detected, 1055 were retested with conventional drug susceptibility testing (DST). Positive predictive value (PPV) of rifampicin resistance detected by Xpert MTB/RIF was 94.7% (CI 91.3-98.1), in comparison to conventional DST. Conclusion Introduction of Xpert MTB/RIF as initial diagnostic test for TB in public health facilities significantly increased case-notification rates of all bacteriologically confirmed TB by 39% and rifampicin-resistant TB case notification by fivefold

Mycobacteriuria in pulmonary tuberculosis patients in Madras, South India

Three consecutive, entire, early morning urine specimens, collected from each of 137 bacteriologically confirmed pulmonary tuberculosis patients aged more than 12 years were processed for culture of M. tuberculosis by the usual centrifugation method. Of the 411 urine specimens, 5 yielded M. tuberculo- sis. About 50 ml each from 405 of the above specimens, from 135 patients, was also processed for culture by a filtration method and M. tuberculosis was isolated from only one of them. In all, mycobacteriuria was present in 5 (3.6%) of 137 patients (95% confidence inter- val being 1.2% to 8.4%). Of these patients, 92 had no history of previous chemotherapy and 3 (3.3%) excreted tubercle bacilli in Urine (95% confidence interval being 0.6% to 9.3%)

Monoclonal antibodies against mycobacterium avium/intracellulare

Ten hybridoma cell lines prodacing monoclonaI antibodies (Mabs) against M. avium/intracellulare (Mai) serotype 8 were raised by the fusion of BALB/c mouse myeloma cells (SPZ) to spleen cells from immunized BALB/c mice. The specificity of the monoclonal antibodies was defined using their differing abilities to bind to sonicates from a range of mycobacterial species and strains. Tbe Mabs showed strain and species specificity. Three Mabs bound only to Mai serotype 8 and 1 Mab bound only to Mai serotypes 8 and 16, the only serotypes tested. The results indicate that Mabs specific for Mai species and serotypes can be produced. These could be useful for serodiagnostic and for epidemiological purposes