Recurrence of pulmonary tuberculosis in India: Findings from the 2019-2021 nationwide community-based TB prevalence survey

Recurrent Tuberculosis patients contribute to a significant proportion of TB burden in India. A nationwide survey was conducted during 2019-2021 across India among adults to estimate the prevalence of TB. A total of 322480 individuals were screened and 1402 were having TB. Of this, 381 (27.1%) had recurrent TB. The crude prevalence (95% CI) of recurrent TB was 118 (107-131) per 100,000 population. The median duration between episodes of TB was 24 months. The proportion of drug resistant TB was 11.3% and 3.6% in the recurrent group and new TB patients respectively. Higher prevalence of recurrent TB was observed in elderly, males, malnourished, known diabetics, smokers, and alcohol users. (p<0.001). To prevent TB recurrence, all treated tuberculosis patients must be followed at least for 24 months, with screening for Chest X-ray, liquid culture every 6 months, smoking cessation, alcohol cessation, nutritional interventions and good diabetic management.

Prevalence and factors associated with tuberculosis infection in India

BACKGROUND

The risk of tuberculosis (TB) disease is higher in individuals with TB infection. In a TB endemic country like India, it is essential to understand the current burden of TB infection at the population level. The objective of the present analysis is to estimate the prevalence of TB infection in India and to explore the factors associated with TB infection.

METHODS

Individuals aged > 15 years in the recently completed National TB prevalence survey in India who were tested for TB infection by QuantiFERON-TB Gold Plus (QFT-Plus) assay were considered for this sub-analysis. TB infection was defined as positive by QFT-Plus (value >0.35 IU/ml). The estimates for prevalence, prevalence ratio (PR) and adjusted risk ratio (aRR) estimates with 95% confidence intervals (CIs) were calculated.

RESULTS

Of the 16864 individuals analysed, the prevalence of TB infection was 22.6% (95% CI:19.4 -25.8). Factors more likely to be associated with TB infection include age > 30 years (aRR:1.49;95% CI:1.29-1.73), being male (aRR:1.26; 95%CI: 1.18-1.34), residing in urban location (aRR:1.58; 95%CI: 1.03-2.43) and past history of TB (aRR:1.49; 95%CI: 1.26-1.76).

CONCLUSION

About one fourth (22.6%) of the individuals were infected with TB in India. Individuals aged > 30 years, males, residing in urban location, and those with past history of TB were more likely to have TB infection. Targeted interventions for prevention of TB and close monitoring are essential to reduce the burden of TB in India.

High incidence of pulmonary tuberculosis in an indigenous Saharia tribe in Madhya Pradesh, central India-A prospective cohort study

BACKGROUND

Lack of TB incidence data is an important evidence gap among Saharia-a high TB burden indigenous community in Madhya Pradesh, central India. The present study was undertaken to calculate the incidence of pulmonary tuberculosis in this tribe.

OBJECTIVE

To calculate the incidence of pulmonary tuberculosis (PTB) among the Saharia tribal population in Madhya Pradesh, central India.

METHODS

A prospective cohort study was conducted among the Saharia tribal population (aged 15 years and above) of Shivpuri district in Madhya Pradesh state in central India. A total of 9,756 individuals were screened for TB in the baseline TB prevalence survey during 2012-13. All available household members were screened for symptoms suggestive of pulmonary TB (presumptive TB). Two sputum specimens were collected from persons having symptoms suggestive of TB and examined by smear and culture tests. A cohort of all non-TB individuals in the baseline survey was followed-up for one year and re-screened for the sysmptoms of PTB in the year 2014-15. Based on the data collected, the incidence of TB over one year period was estimated per 100,000 population.

RESULTS

A total of 9756 and 9044 individuals (≥ 15 years) were screened for symptoms suggestive of PTB during baseline and endline surveys respectively. The sputum specimens of presumptive TB cases were collected and examined by smear and culture tests. The overall incidence of bacteriologically positive (smear and/or culture) PTB over one year period was 1504 (95% Confidence Interval (CI): 1273-1776) per 100,000 in the study population, the incidence of smear-positive PTB was 1106 (95% CI: 910-1343), and the incidence of culture-positive PTB was 1084 (95% CI: 890-1319) per 100,000 population. The incidence for both smear and culture-positive PTB was 686 (95% CI: 535-878) per 100,000 population in the year 2014-15. The incidence of PTB was 2.8 times higher in males compared to females (2259 vs 807 per 100,000) and was positively correlated with age.

CONCLUSION

The findings of the study, the first of its kind in the Saharia tribal population, indicate a high incidence of TB in this tribal community thereby highlighting the urgent need for focused and intensified efforts to achieve the goal of TB elimination in the country.

TB free India: Reaching the unreached tribal population under National Tuberculosis Elimination Programme

India is the highest TB burden country in the world. The burden however is not uniform in different strata including tribal population - one of the key affected populations in the country. As the evidences from tribal population are hardly available, most of the policies and strategies implemented under National Tuberculosis Elimination Programme (NTEP) are usually based on the evidences from general populations. NTEP is continuously taking steps to strengthen TB services in tribal areas. The Social Action Plan including Tribal Action Plan is in place and the appropriate strategies are incorporated in the National Strategic Plan (NSP) to ensure universal access to quality TB services to vulnerable population groups. However, its implementation becomes challenging especially in tribal areas as different tribal groups have their own unique ways of dealing with health issues. These issues are therefore required to be addressed holistically involving all the stakeholders. In view of this a symposium was jointly organized by the Central TB Division (CTD), Govt. of India and ICMR - National Institute of Research in Tribal Health (NIRTH), Jabalpur on 17th and 18th December, 2019 at ICMR - NIRTH, Jabalpur. It provided an excellent platform for all the stakeholders from different parts of the country to share their experiences in tuberculosis particularly among marginalized populations. The recommendations emerged out of this interactive symposium highlight the sincere effort of NTEP to tackle TB situation in tribal population and show the way forward towards India's TB elimination goal by 2025 especially in hard to reach tribal areas.

Reasons for loss to follow-up (LTFU) of pulmonary TB (PTB) patients: A qualitative study among Saharia, a particularly vulnerable tribal group of Madhya Pradesh, India

BACKGROUND

Loss to follow-up (LTFU) among pulmonary tuberculosis (PTB) patients is a significant challenge for TB control. However, there is a dearth of information about the factors leading to LTFU among marginalized communities. This study highlights the factors associated with LTFU in Saharia, a tribe of Madhya Pradesh having high tuberculosis (TB) prevalence.

METHODS

A qualitative study was carried out during January-April 2020 among twenty-two pulmonary TB patients, recorded as LTFU in NIKSHAY, with ten treatment supporters and ten patient's family members. Semi-structured personal interview tools were used to collect the information on the history of anti-tuberculosis treatment, adverse drug events (ADE), social cognitive, behaviors, myths, and misbeliefs. The interviews were transcribed and thematically analysed to examine underlying themes.

RESULTS

The study explored various social, behavioral factors leading to loss to follow-up among PTB patients. Drug side effects, alcoholism, social stigma, lack of awareness of the seriousness of the diseases and poor counseling are the main barriers to treatment adherence in this community.

CONCLUSIONS

The study highlights the need to address the issues related to LTFU during TB treatment. The enhanced efforts of treatment supporters, health staff, and family & community persons must motivate and support the patients.

Persistent high prevalence of pulmonary tuberculosis in a resource-limited setting: threat to India's TB Free campaign

BACKGROUND

Tuberculosis (TB) is a major public health problem among Saharia, a particularly vulnerable tribal group residing in remote rural areas in central India. This article presents the findings from the baseline survey among Saharias and provides comprehensive prevalence data of pulmonary TB (PTB) in this marginalised community.

METHODS

A community-based cross-sectional PTB prevalence survey was carried out during January-May 2019 in selected villages using multistage stratified cluster sampling. All eligible adults (≥15 years of age) were screened for the symptoms of PTB. Sputum samples were collected and processed for microscopy and culture for Mycobacterium tuberculosis.

RESULTS

A total of 20 114 eligible individuals were screened for symptoms of PTB. Among these, 3001 (14.9%) individuals reported at least one PTB symptom and sputum was collected from 2890 (96.3%) individuals. Among these, 273 (9.4%) were bacteriologically positive for PTB. The overall prevalence was 1357 per 100 000 population.

CONCLUSIONS

The findings indicate that TB continues to be a major health problem in this marginalised community despite large investments by the government for TB control. This emphasizes the need to look into the causes and barriers in implementation of the TB elimination programme in the community, especially in view of India's TB elimination goal by 2025.

Seroprevalence of IgG antibodies against SARS-CoV-2 among the general population and healthcare workers in India, June-July 2021: A population-based cross-sectional study

BACKGROUND

India began COVID-19 vaccination in January 2021, initially targeting healthcare and frontline workers. The vaccination strategy was expanded in a phased manner and currently covers all individuals aged 18 years and above. India experienced a severe second wave of COVID-19 during March-June 2021. We conducted a fourth nationwide serosurvey to estimate prevalence of SARS-CoV-2 antibodies in the general population aged ≥6 years and healthcare workers (HCWs).

METHODS AND FINDINGS

We did a cross-sectional study between 14 June and 6 July 2021 in the same 70 districts across 20 states and 1 union territory where 3 previous rounds of serosurveys were conducted. From each district, 10 clusters (villages in rural areas and wards in urban areas) were selected by the probability proportional to population size method. From each district, a minimum of 400 individuals aged ≥6 years from the general population (40 individuals from each cluster) and 100 HCWs from the district public health facilities were included. The serum samples were tested for the presence of IgG antibodies against S1-RBD and nucleocapsid protein of SARS-CoV-2 using chemiluminescence immunoassay. We estimated the weighted and test-adjusted seroprevalence of IgG antibodies against SARS-CoV-2, along with 95% CIs, based on the presence of antibodies to S1-RBD and/or nucleocapsid protein. Of the 28,975 individuals who participated in the survey, 2,892 (10%) were aged 6-9 years, 5,798 (20%) were aged 10-17 years, and 20,285 (70%) were aged ≥18 years; 15,160 (52.3%) participants were female, and 21,794 (75.2%) resided in rural areas. The weighted and test-adjusted prevalence of IgG antibodies against S1-RBD and/or nucleocapsid protein among the general population aged ≥6 years was 67.6% (95% CI 66.4% to 68.7%). Seroprevalence increased with age (p < 0.001) and was not different in rural and urban areas (p = 0.822). Compared to unvaccinated adults (62.3%, 95% CI 60.9% to 63.7%), seroprevalence was significantly higher among individuals who had received 1 vaccine dose (81.0%, 95% CI 79.6% to 82.3%, p < 0.001) and 2 vaccine doses (89.8%, 95% CI 88.4% to 91.1%, p < 0.001). The seroprevalence of IgG antibodies among 7,252 HCWs was 85.2% (95% CI 83.5% to 86.7%). Important limitations of the study include the survey design, which was aimed to estimate seroprevalence at the national level and not at a sub-national level, and the non-participation of 19% of eligible individuals in the survey.

CONCLUSIONS

Nearly two-thirds of individuals aged ≥6 years from the general population and 85% of HCWs had antibodies against SARS-CoV-2 by June-July 2021 in India. As one-third of the population is still seronegative, it is necessary to accelerate the coverage of COVID-19 vaccination among adults and continue adherence to non-pharmaceutical interventions.

Comparative Yield of Pulmonary Tuberculosis by Different Symptoms among Saharia Tribe of Madhya Pradesh, India

Background

Symptom elicitation is a simple and inexpensive screening tool used for population screening in tuberculosis (TB) prevalence surveys. However, the information on the yield of TB cases by symptoms is sparsely available.

Methods

A cross-sectional pulmonary TB (PTB) prevalence survey was conducted. All available eligible individuals were interviewed for symptoms of PTB. Sputum samples were collected and tested for PTB by smear microscopy and culture.

Results

Among 2890 individuals tested for PTB, 77% had cough for 2 weeks or more and one-third reported chest pain for 1 month or more. About 31% were having a history of anti-TB treatment. Cough contributed to 82% PTB cases and the history of anti-TB treatment contributed to another 8.4% confirmed cases. Fever recorded lowest yield among the symptoms of PTB.

Conclusion

The study suggests that fever alone may be ignored from symptomatic elicitation, and history of previous anti-TB treatment should be treated as an important indication for PTB symptomatic elicitation.

Extensively drug-resistant tuberculosis treated with bedaquiline: A case report in the particularly vulnerable tribal group of Madhya Pradesh, India

The management of drug-resistant (DR) tuberculosis (TB) remains a challenge particularly in remote rural areas of the country. Although the treatment with wholly oral drug regimens, including bedaquiline (BDQ) and delamanid, is rolled out under the National TB Elimination Program, little is known about its coverage and the effectiveness in hard-to-reach tribal areas. The present report describes the early identification and successful management, through team effort, of a case of extensively DR TB belonging to the Saharia tribe - a Particularly Vulnerable Tribal Groups (PVTGs) of Madhya Pradesh, which has a very high prevalence of TB. The BDQ-containing regimen was well tolerated and found effective with minimal side effects and contributed to the reduced time to culture conversion and radiological improvements. The concerted efforts and strategies need to be adopted for effective implementation of Programmatic management of DR TB (PMDT) guidelines in remote tribal areas of the country.

Experiences and needs of patients with MDR/XDR-TB: a qualitative study among Saharia tribe in Madhya Pradesh, Central India

BACKGROUND

Drug-resistant tuberculosis (DR-TB) continues to be a major public health threat posing a critical challenge to TB treatment and control worldwide. The present study was conducted among patients with DR-TB of the Saharia tribe residing in Madhya Pradesh state of Central India to document their experiences and needs, and to identify gaps for treatment adherence as this population is known to be poor because of migration and other factors.

METHODS

We conducted 16 in-depth interviews on purposively selected patients with DR-TB among the Saharia tribe using a predesigned open-ended in-depth interview guide, which included questions on domains like general physical health, diagnosis, treatment adherence, side-effects of drugs and experience related to the health facility. Out of these interviews, various subthemes were extracted. The obtained qualitative data were subjected to thematic analysis.

RESULTS

The study helped to understand the experiences and needs of the patients with DR-TB in various stages from diagnosis to treatment. Also, there was the impact of factors like lack of education and awareness, poor living conditions and lack of healthcare facilities on predominance of the disease in the community. Poor access to a healthcare facility, high pill burden and related side-effects, longer duration of treatment, financial burden, misbeliefs and misconceptions were prominent issues posing a challenge to treatment adherence. The narratives pointed out their struggle at every stage be it with diagnosis, treatment initiation or treatment adherence.

CONCLUSION

It is paramount to address the needs and experiences of patients with DR-TB to develop a patient-centric and context-specific approach conducive to the sociocultural set-up of tribal people. This will scale down the attrition rate of tribal patients while adhering to the complete treatment process and reducing the high burden of TB among the Saharia community. In addition, tribal patients should be counselled at regular intervals to increase their confidence in the treatment.

Long-term survival of patients treated for tuberculosis: a population-based longitudinal study in a resource-poor setting

OBJECTIVE

We assessed the long-term survival of TB patients belonging to the Saharia tribe, a high TB burden community in Shivpuri district, Madhya Pradesh, central India.

METHODS

Population-based, longitudinal study conducted among 9756 Saharia population in 2013, and a resurvey done 2 years later in 2015 using the same methods. The status of the individuals during resurvey was recorded as non-TB, relapse and death. The deaths recorded in this period were used to measure the mortality among TB-affected population and the non-TB population in this cohort.

RESULTS

The standardised mortality ratio for the study cohort was 122.9 per 1000 population; males had higher mortality than females (129.9 vs. 96.8). The expected mortality among the non-TB population was 30.2, and the observed mortality among TB-affected population was 122.9 per 1000 population.

CONCLUSION

In the Saharia tribe, post-treatment mortality in the TB-affected population is significantly higher than in the general population. This highlights an urgent need for implementation of effective public health strategies to prevent disproportionate deaths among TB-affected individuals in resource-poor settings, and the importance of periodic follow-up of patients after cure/completion of treatment, especially in vulnerable populations.

SARS-CoV-2 seroprevalence among the general population and healthcare workers in India, December 2020-January 2021

BACKGROUND

Earlier serosurveys in India revealed seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) of 0.73% in May-June 2020 and 7.1% in August-September 2020. A third serosurvey was conducted between December 2020 and January 2021 to estimate the seroprevalence of SARS-CoV-2 infection among the general population and healthcare workers (HCWs) in India.

METHODS

The third serosurvey was conducted in the same 70 districts as the first and second serosurveys. For each district, at least 400 individuals aged ≥10 years from the general population and 100 HCWs from subdistrict-level health facilities were enrolled. Serum samples from the general population were tested for the presence of immunoglobulin G (IgG) antibodies against the nucleocapsid (N) and spike (S1-RBD) proteins of SARS-CoV-2, whereas serum samples from HCWs were tested for anti-S1-RBD. Weighted seroprevalence adjusted for assay characteristics was estimated.

RESULTS

Of the 28,598 serum samples from the general population, 4585 (16%) had IgG antibodies against the N protein, 6647 (23.2%) had IgG antibodies against the S1-RBD protein, and 7436 (26%) had IgG antibodies against either the N protein or the S1-RBD protein. Weighted and assay-characteristic-adjusted seroprevalence against either of the antibodies was 24.1% [95% confidence interval (CI) 23.0-25.3%]. Among 7385 HCWs, the seroprevalence of anti-S1-RBD IgG antibodies was 25.6% (95% CI 23.5-27.8%).

CONCLUSIONS

Nearly one in four individuals aged ≥10 years from the general population as well as HCWs in India had been exposed to SARS-CoV-2 by December 2020.

Epidemiology of rotavirus diarrhea among children less than 5 years hospitalized with acute gastroenteritis prior to rotavirus vaccine introduction in India

Background

Rotavirus is an important cause of severe diarrhea requiring hospitalization, accounting for approximately 78,000 deaths annually in Indian children below 5 years of age. We present epidemiological data on severe rotavirus disease collected during hospital-based surveillance in India before the introduction of the oral rotavirus vaccine into the national immunization schedule.

Methods

The National Rotavirus Surveillance Network was created involving 28 hospital sites and 11 laboratories across the four geographical regions of India. From September 2012 to August 2016 children less than 5 years of age hospitalized for diarrhea for at least 6 h, were enrolled. After recording clinical details, a stool sample was collected from each enrolled child, which was tested for rotavirus antigen using enzyme immunoassay (EIA). Nearly 2/3rd of EIA positive samples were genotyped using reverse transcription polymerase chain reaction to identify the G and P types.

Results

Of the 21,421 children enrolled during the 4 years surveillance, 36.3% were positive for rotavirus. The eastern region had the highest proportion of rotavirus associated diarrhea (39.8%), while the southern region had the lowest (33.8%). Rotavirus detection rates were the highest in children aged 6–23 months (41.8%), and 24.7% in children aged < 6 months. Although rotavirus associated diarrhea was seen throughout the year, the highest positivity was documented between December and February across all the regions. The most common rotavirus genotype was G1P[8] (52.9%), followed by G9P4 (8.7%) and G2P4 (8.4%).

Conclusions

There is high burden of rotavirus gastroenteritis among Indian children below 5 years of age hospitalized for acute diarrhea thereby highlighting the need for introduction of rotavirus vaccine into the national immunization program and also for monitoring circulating genotypes.

Diversity of rotavirus genotypes circulating in children < 5 years of age hospitalized for acute gastroenteritis in India from 2005 to 2016: analysis of temporal and regional genotype variation

Background

From 2016, the Government of India introduced the oral rotavirus vaccine into the national immunization schedule. Currently, two indigenously developed vaccines (ROTAVAC, Bharat Biotech; ROTASIIL, Serum Institute of India) are included in the Indian immunization program. We report the rotavirus disease burden and the diversity of rotavirus genotypes from 2005 to 2016 in a multi-centric surveillance study before the introduction of vaccines.

Methods

A total of 29,561 stool samples collected from 2005 to 2016 (7 sites during 2005–2009, 3 sites from 2009 to 2012, and 28 sites during 2012–2016) were included in the analysis. Stools were tested for rotavirus antigen using enzyme immunoassay (EIA). Genotyping was performed on 65.8% of the EIA positive samples using reverse transcription- polymerase chain reaction (RT-PCR) to identify the G (VP7) and P (VP4) types. Multinomial logistic regression was used to quantify the odds of detecting genotypes across the surveillance period and in particular age groups.

Results

Of the 29,561 samples tested, 10,959 (37.1%) were positive for rotavirus. There was a peak in rotavirus positivity during December to February across all sites. Of the 7215 genotyped samples, G1P[8] (38.7%) was the most common, followed by G2P[4] (12.3%), G9P[4] (5.8%), G12P[6] (4.2%), G9P[8] (4%), and G12P[8] (2.4%). Globally, G9P[4] and G12P[6] are less common genotypes, although these genotypes have been reported from India and few other countries. There was a variation in the geographic and temporal distribution of genotypes, and the emergence or re-emergence of new genotypes such as G3P[8] was seen. Over the surveillance period, there was a decline in the proportion of G2P[4], and an increase in the proportion of G9P[4]. A higher proportion of mixed and partially typed/untyped samples was also seen more in the age group 0–11 months.

Conclusions

This 11 years surveillance highlights the high burden of severe rotavirus gastroenteritis in Indian children < 5 years of age before inclusion of rotavirus vaccines in the national programme. Regional variations in rotavirus epidemiology were seen, including the emergence of G3P[8] in the latter part of the surveillance. Having pre-introduction data is important to track changing epidemiology of rotaviruses, particularly following vaccine introduction.

Prevalence of SARS-CoV-2 infection in India: Findings from the national serosurvey, May-June 2020

BACKGROUND & OBJECTIVES

Population-based seroepidemiological studies measure the extent of SARS-CoV-2 infection in a country. We report the findings of the first round of a national serosurvey, conducted to estimate the seroprevalence of SARS-CoV-2 infection among adult population of India.

METHODS

From May 11 to June 4, 2020, a randomly sampled, community-based survey was conducted in 700 villages/wards, selected from the 70 districts of the 21 States of India, categorized into four strata based on the incidence of reported COVID-19 cases. Four hundred adults per district were enrolled from 10 clusters with one adult per household. Serum samples were tested for IgG antibodies using COVID Kavach ELISA kit. All positive serum samples were re-tested using Euroimmun SARS-CoV-2 ELISA. Adjusting for survey design and serial test performance, weighted seroprevalence, number of infections, infection to case ratio (ICR) and infection fatality ratio (IFR) were calculated. Logistic regression was used to determine the factors associated with IgG positivity.

RESULTS

Total of 30,283 households were visited and 28,000 individuals were enrolled. Population-weighted seroprevalence after adjusting for test performance was 0.73 per cent [95% confidence interval (CI): 0.34-1.13]. Males, living in urban slums and occupation with high risk of exposure to potentially infected persons were associated with seropositivity. A cumulative 6,468,388 adult infections (95% CI: 3,829,029-11,199,423) were estimated in India by the early May. The overall ICR was between 81.6 (95% CI: 48.3-141.4) and 130.1 (95% CI: 77.0-225.2) with May 11 and May 3, 2020 as plausible reference points for reported cases. The IFR in the surveyed districts from high stratum, where death reporting was more robust, was 11.72 (95% CI: 7.21-19.19) to 15.04 (9.26-24.62) per 10,000 adults, using May 24 and June 1, 2020 as plausible reference points for reported deaths.

INTERPRETATION & CONCLUSIONS

Seroprevalence of SARS-CoV-2 was low among the adult population in India around the beginning of May 2020. Further national and local serosurveys are recommended to better inform the public health strategy for containment and mitigation of the epidemic in various parts of the country.

Declining tuberculosis prevalence in Saharia, a particularly vulnerable tribal community in Central India: evidences for action

Background

In spite of an alarmingly high tuberculosis (TB) burden amongst the Saharia tribe of central India, there is hardly any study to investigate the impact of DOTS implementation on the magnitude of tuberculosis disease and the changes over time. This article present the findings of TB prevalence surveys conducted amongst this indigenous population in two different time periods to know the change in the prevalence of TB.

Methods

A cross sectional survey was conducted among Saharia population in Shivpuri district, Madhya Pradesh during February 2013 to May 2013 and resurvey during March 2015 to July 2015. All individuals (≥15 years) were examined for chest symptoms suggestive of TB. Sputum samples were collected from all presumptive TB cases and were confirmed by laboratory examination by Ziehl-Neelsen smear microscopy and solid media culture methods. All detected cases were referred to health facility for anti-tuberculosis treatment as per RNTCP guidelines.

Results

There was significant reduction (trend Chi square 19.97; OR = 1.521; p = 0.000) in the prevalence of TB at the endline (1995 per 100,000) as compared to baseline (3003 per 100,000). The reduction was significant among males as compared to females (OR 1.55; p = 0.000) and in the age group of 25–34 years (OR 2.0; p = 0.007) and 45–54 years (OR 4.39; p = 0.003). There was significant reduction in the prevalence in both smear (OR 1.29; p = 0.02) and culture positive (OR 1.57; p = 0.000) TB at the endline survey.

Conclusion

The study findings highlight a reduction in the prevalence of TB among Saharia tribal population. Further studies are needed to identify the factors associated with reduction in prevalence among this population and also further surveys to monitor the prevalence trend over a period.

Recurrence of tuberculosis among newly diagnosed sputum positive pulmonary tuberculosis patients treated under the Revised National Tuberculosis Control Programme, India: A multi-centric prospective study

Introduction

There is lack of information on the proportion of new smear—positive pulmonary tuberculosis (PTB) patients treated with a 6-month thrice-weekly regimen under Revised National Tuberculosis Control Programme (RNTCP) who develop recurrent TB after successful treatment outcome.

Objective

To estimate TB recurrence among newly diagnosed PTB patients who have successfully completed treatment and to document endogenous reactivation or re-infection. Risk factors for unfavourable outcomes to treatment and TB recurrence were determined.

Methodology

Adult (aged ≥ 18 yrs) new smear positive PTB patients initiated on treatment under RNTCP were enrolled from sites in Tamil Nadu, Karnataka, Delhi, Maharashtra, Madhya Pradesh and Kerala. Those declared “treatment success” at the end of treatment were followed up with 2 sputum examinations each at 3, 6 and 12 months after treatment completion. MIRU-VNTR genotyping was done to identify endogenous re-activation or exogenous re-infection at TB recurrence. TB recurrence was expressed as rate per 100 person-years (with 95% confidence interval [95%CI]). Regression models were used to identify the risk factors for unfavourable response to treatment and TB recurrence.

Results

Of the1577 new smear positive PTB patients enrolled, 1565 were analysed. The overall cure rate was 77% (1207/1565) and treatment success was 77% (1210 /1565). The cure rate varied from 65% to 86%. There were 158 of 1210 patients who had TB recurrence after treatment success. The pooled TB recurrence estimate was 10.9% [95%CI: 0.2–21.6] and TB recurrence rate per 100 person–years was 12.7 [95% CI: 0.4–25]. TB recurrence per 100 person–years varied from 5.4 to 30.5. Endogenous reactivation was observed in 56 (93%) of 60 patients for whom genotyping was done. Male gender was associated with TB recurrence.

Conclusion

A substantial proportion of new smear positive PTB patients successfully treated with 6 –month thrice-weekly regimen have TB recurrence under program settings.

A comparative study of the socio-economic risk factors for pulmonary tuberculosis in the Saharia tribe of Madhya Pradesh, India

Background

To determine the socio-economic risk factors for pulmonary tuberculosis (PTB) in the Saharia tribal community in Madhya Pradesh, Central India.

Methods

PTB cases detected during the year 2013-14 through a community active TB prevalence survey in the Shivpuri district, Madhya Pradesh were included in the study. For each case, three controls were selected randomly among the non-cases from the same village and the data on socio-economic risk factors were collected. Using logistic regression analysis, the risk factors for PTB disease were identified.

Results

A total of 220 cases and 660 controls participated in the study. Of the 13 risk factors studied, on multivariate analysis the risk of PTB was found to be significantly associated with malnutrition (adjusted odds ratio [AOR] 2.02 [95% confidence interval {CI} 1.46 to 2.79]), living in a kaccha (built of naturally occurring materials) house (AOR 2.72 [95% CI 1.44 to 5.11]) and tobacco smoking (mostly beedis; AOR 1.59 [95% CI 1.12 to 2.18]).

Conclusions

The findings highlight that malnutrition, poor living conditions in a Kaccha house (built of naturally occurring materials) and tobacco smoking are the major risk factors for PTB among Saharias, which need to be studied among other tribal populations in the country. There is a need to strengthen health and nutrition programmes in this community.

Stochastics of Cellular Differentiation Explained by Epigenetics: The Case of T-Cell Differentiation and Functional Plasticity

Epigenetic marks including histone modifications and DNA methylation are associated with the regulation of gene expression and activity. In addition, an increasing number of non-coding RNAs with regulatory activity on gene expression have been identified. Alongside, technological advancements allow for the analysis of these mechanisms with high resolution up to the single-cell level. For instance, the assay for transposase-accessible chromatin using sequencing (ATAC-seq) simultaneously probes for chromatin accessibility and nucleosome positioning. Thus, it provides information on two levels of epigenetic regulation. Development and differentiation of T cells into functional subset cells including memory T cells are dynamic processes driven by environmental signals. Here, we briefly review the current knowledge of how epigenetic regulation contributes to subset specification, differentiation and memory development in T cells. Specifically, we focus on epigenetic mechanisms differentially active in the two distinct T cell populations expressing αβ or γδ T cell receptors. We also discuss examples of epigenetic alterations of T cells in autoimmune diseases. DNA methylation and histone acetylation are subject to modification by several classes of 'epigenetic modifiers', some of which are in clinical use or in preclinical development. Therefore, we address the impact of some epigenetic modifiers on T-cell activation and differentiation, and discuss possible synergies with T cell-based immunotherapeutic strategies.

Investigation of the risk factors for pulmonary tuberculosis: A case-control study among Saharia tribe in Gwalior district, Madhya Pradesh, India

BACKGROUND & OBJECTIVES

Prevalence of pulmonary tuberculosis (PTB) is known to be high in the indigenous tribal community Saharia in Madhya Pradesh, India. The risk factors for PTB are not well known among them. This study was done to determine various risk factors associated with PTB in the indigenous community Saharia.

METHODS

A prevalence survey was conducted among Saharias of Gwalior district of Madhya Pradesh. The population surveyed was 12,123 which was the source of cases and controls for the present study. All the bacillary-positive cases and controls in the ratio of 1:5 were included in the survey. Data were collected by the trained health workers from the patients and controls using a semi-structured pre-coded and pre-tested questionnaire which included data on risk factors including demographic factors, host-related factors and household factors. The individuals were also screened for diabetes mellitus and HIV.

RESULTS

Malnutrition and history of asthma were associated with an increased risk of PTB. More than 56 per cent cases were attributed to malnutrition and 12 per cent attributed to asthma. Low family income, alcohol consumption and smoking were the other contributors. The risk was higher in males as compared to females.

INTERPRETATION & CONCLUSIONS

The study emphasized that the main contributors were social factors. Nutrition supplementation, especially in tuberculosis (TB) patients and integrated approach to improve their living conditions are needed to control TB in this community.

Research on tuberculosis in tribal areas in India: A systematic review

BACKGROUND

Tuberculosis (TB) remains a major public health problem in resource-poor countries including India. Scientific knowledge is used to guide policy and practice. There is however, a limited, systematically collected data required for guiding the scale-up of interventions particularly amongst vulnerable populations including tribal groups in the country. In view of this, a systematic review of the TB research studies carried out in tribal areas of different parts of the country was undertaken.

OBJECTIVE

To undertake a systematic review of the TB research studies carried out in tribal areas of India between 1996 and 2016.

METHODS

A systematic review of English articles published between 1996 and 2016 on any aspect of TB was done through internet searches using Literature search EndNote programme. The words used for searching were tuberculosis, India, tribal, indigenous, disadvantaged, adivasi. The most common topics classified as annual risk of tuberculosis infection (ARTI), prevalence of TB, laboratory studies, clinical symptoms of TB, risk factors for TB, knowledge attitude practice, community Directly Observed Treatment (DOT) providers, performance of Revised National Tuberculosis Control Programme (RNTCP), and drug resistant TB. Classification was also done on the basis of the type of tribe studied and place of study conducted. A total of 47 studies identified through the search were included in the review.

RESULTS

Of the 47 studies reviewed, 12 were on TB prevalence, 7 were laboratory studies, four on ARTI and 5 on performance of RNTCP in tribal areas. Among these, majority (23 studies) of the tribal studies did not mention the type of tribe. Ten studies were conducted among Saharia, a particularly vulnerable tribal group in the Indian state of Madhya Pradesh mainly by the National Institute for Research on Tribal Health, five were among the mixed tribes and very few on other tribes.

CONCLUSION

The systematic review indicates that the research studies on TB among tribal population are very few. There is a need to invest and encourage researcher to work on the research plans for the control of TB in tribal areas.

Discovery of Imidazo[1,2-a]pyridine Ethers and Squaramides as Selective and Potent Inhibitors of Mycobacterial Adenosine Triphosphate (ATP) Synthesis

The approval of bedaquiline to treat tuberculosis has validated adenosine triphosphate (ATP) synthase as an attractive target to kill Mycobacterium tuberculosis (Mtb). Herein, we report the discovery of two diverse lead series imidazo[1,2-a]pyridine ethers (IPE) and squaramides (SQA) as inhibitors of mycobacterial ATP synthesis. Through medicinal chemistry exploration, we established a robust structure-activity relationship of these two scaffolds, resulting in nanomolar potencies in an ATP synthesis inhibition assay. A biochemical deconvolution cascade suggested cytochrome c oxidase as the potential target of IPE class of molecules, whereas characterization of spontaneous resistant mutants of SQAs unambiguously identified ATP synthase as its molecular target. Absence of cross resistance against bedaquiline resistant mutants suggested a different binding site for SQAs on ATP synthase. Furthermore, SQAs were found to be noncytotoxic and demonstrated efficacy in a mouse model of tuberculosis infection.

Health literacy on tuberculosis amongst vulnerable segment of population: special reference to Saharia tribe in central India

BACKGROUND & OBJECTIVES

Health literacy on tuberculosis (TB) is an understanding about TB to perform activities with regard to prevention, diagnosis and treatment. We undertook a study to assess the health literacy on TB among one of the vulnerable tribal groups (Saharia) in central India.

METHODS

In this cross-sectional study, 2721 individuals aged >15 yr from two districts of Madhya Pradesh State of India were interviewed at their residence during December 2012-July 2013. By using a short-form questionnaire, health literacy on cause, symptoms, mode of transmission, diagnosis, treatment and prevention of TB was assessed.

RESULTS

Of the 2721 (Gwalior 1381; Shivpuri 1340) individuals interviewed; 76 per cent were aged <45 yr. Living condition was very poor (62% living in huts/katcha houses, 84 per cent with single room, 89 per cent no separate kitchen, 97 per cent used wood/crop as a fuel). Overall literacy rate was 19 per cent, and 22 per cent had >7 members in a house. Of the 2721 respondents participated, 52 per cent had never heard of TB; among them 8 per cent mentioned cough as a symptom, 64 per cent mentioned coughing up blood, and 91 per cent knew that TB diagnosis, and treatment facilities were available in both government and private hospitals. Health literacy score among participants who had heard of TB was <40 per cent among 36 per cent of respondents, 41-60 per cent among 54 per cent and >60 per cent among 8 per cent of respondents.

INTERPRETATION & CONCLUSIONS

The finding that nearly half of the respondents had not heard of TB indicated an important gap in education regarding TB in this vulnerable population. There is an urgent need to implement targeted interventions to educate this group for better TB control.

Pulmonary tuberculosis - a health problem amongst Saharia tribe in Madhya Pradesh

Background & objectives:

The information on tuberculosis (TB) situation amongst Saharia, one of the particularly vulnerable tribal groups (PVTGs) in Madhya Pradesh, is not available from Gwalior division of the State. Hence, this study was undertaken to estimate the prevalence of pulmonary tuberculosis (PTB) disease amongst them.

Methods:

A community based cross-sectional TB prevalence survey was undertaken among Saharia PVTG in Gwalior district of Madhya Pradesh. A random sample of villages predominated by Saharia tribe was selected from all the blocks in proportion to the size of Saharia population in each block of the district. All eligible individuals were questioned for chest symptoms relating to TB. Two sputum samples were collected from each of the eligible individuals, transported to the laboratory, and were examined by Ziehl-Neelsen(ZN) smear microscopy and solid media culture methods.

Results:

Of the total 10,259 individuals eligible for screening, 9,653 (94.1%) were screened for symptoms. Overall prevalence of PTB was found to be 3294 per 100,000. The prevalence increased with age and the trend was significant (P<0.001). The prevalence of TB was significantly higher amongst males (5497/100,000) as compared to females (1376/100,000) (P<0.001).

Interpretation & conclusions:

The study results provide vital information on the current situation of pulmonary TB disease among the Saharia tribal community in Gwalior district of Madhya Pradesh. In view of high PTB disease prevalence among this PVTG, there is an urgent need to improve and further intensify TB control measures in this area.

Situation of drug resistant tuberculosis in Saharia tribe of central India

BACKGROUND & OBJECTIVES

The information on multidrug resistant tuberculosis (MDR-TB) situation amongst Saharia, one of the Particularly Vulnerable Tribal Groups (PVTGs) in Madhya Pradesh, India, is not available. Hence, this study was undertaken to find the situation of MDR-TB amongst Saharia PVTG in two districts of Madhya Pradesh.

METHODS

Community based cross-sectional TB prevalence surveys were conducted among Saharia PVTG in Gwalior and Shivpuri districts of Madhya Pradesh. Chest symptomatics were identified from the individual registered for the study. Two sputum samples were collected from each of the eligible individuals, transported to the laboratory, and were examined by Ziehl-Neelsen (Z-N) smear microscopy and solid medium culture methods. Drug susceptibility testing of the isolates was done by indirect proportion method on solid medium.

RESULTS

MDR rate was 2.2 per cent of new cases and 8.2 per cent among the previously treated cases of TB in Gwalior while it was two per cent among the previously treated cases in Shivpuri district.

INTERPRETATION & CONCLUSIONS

Though the prevalence of tuberculosis in these districts was alarmingly high, the MDR rates were more or less similar to national average. However, the findings of this study highlight the need for active intervention so that the MDR-TB is kept under control.

A re-appraisal of publication rates of scientific papers presented at the Otorhinolaryngology Research Society meetings

OBJECTIVES

To review the rate of publication of papers in peer-reviewed journals after oral presentations at the Otorhinolaryngology Research Society meetings between 1996 and 2013 and to compare trends with the previous review (1979-1995).

DESIGN

Literature review.

SETTING

Merseyside ENT Research Collaborative.

PARTICIPANTS

The abstracts of presentations at Otorhinolaryngology Research Society meetings are published in Clinical Otolaryngology. A structured search of PubMed was undertaken to identify published Otorhinolaryngology Research Society presentations.

MAIN OUTCOME MEASURES

Publication rates.

RESULTS

A total of 460 abstracts were identified. The interobserver reliability among reviewers was 98%. Of the total, 259 (56.3%) abstracts were published in peer-reviewed journals. The average time from Otorhinolaryngology Research Society presentation to publication was 27.7 months (median 23), which was not significantly different from the previous review. Publication by subspeciality was as follows: head and neck (45.6%), otology (30.5%), rhinology (22%) and others (1.9%). Most published Otorhinolaryngology Research Society presentations were published in Clinical Otolaryngology (22.4%), followed by the Journal of Laryngology and Otology (8.1%) and the Laryngoscope (7.3%). Clinical research was the most common category of abstracts being presented at Otorhinolaryngology Research Society meetings, followed by laboratory-based research. Over half (56.5%) of laboratory research presented were head and neck themed, while otology and rhinology predominated clinical research presentations. Over half (52.1%) of Otorhinolaryngology Research Society abstracts originated from units in the North of England. Bristol presented the most abstracts (30.1%), followed by Newcastle (25.1%).

CONCLUSIONS

The publication rate of Otorhinolaryngology Research Society presentations remains high and many are subsequently published in high-impact factor otolaryngology journals. More Otorhinolaryngology Research Society presentations are now published in American and European journals.

Scaffold morphing leading to evolution of 2,4-diaminoquinolines and aminopyrazolopyrimidines as inhibitors of the ATP synthesis pathway

2,4-Diaminoquinazolines, 2,4-diaminoquinolines and aminopyrazolopyrimidines, inhibitors of mycobacterial ATP synthesis, are novel lead molecules towards discovery and development of new anti-tubercular agents.

Yield of pulmonary tuberculosis cases by symptoms: Findings from a community survey in Madhya Pradesh, central India

A cross-sectional tuberculosis prevalence survey was undertaken in Jabalpur district, Madhya Pradesh, central India. All individuals were questioned for chest symptoms. Sputum samples were collected and examined for microscopy and culture. Overall prevalence of sputum positive pulmonary tuberculosis was found to be 255.3 per 100,000 population. Cough, with or without other symptoms, was present in 75.5% individuals and yielded 88.2% of the detected pulmonary tuberculosis cases. Elicitation of a previous history of treatment yielded 5.9%, and chest pain 4.5% cases. History of fever alone yielded no cases. The findings suggest that a history of fever alone may be safely excluded from the list of symptoms to be elicited in future TB prevalence surveys in India.

Performance of Revised National Tuberculosis Control Programme (RNTCP) in tribal areas in India

BACKGROUND & OBJECTIVES

The Revised National Tuberculosis Control Programme (RNTCP) provides free diagnostic and treatment services to all tuberculosis (TB) patients registered under it. Equitable access, implying a preference for the most hard-to-reach groups particularly for tribal areas, is a major concern for RNTCP. This study was conducted to assess the performance of RNTCP in terms of case detection and cure rates in areas dominated by tribal groups in India.

METHODS

We used the RNTCP data collected by the Central TB Divison, Government of India. RNTCP has a systematic monitoring mechanism which tracks the outcome of every patient put on treatment. There is a standardized recording and reporting structure in place; indicators are monitored regularly at every level of the health system; and regular supervision ensures quality of the Programme. The main indicators include the number of cases diagnosed and the percentage of patients who are successfully treated. These indicators were used to assess the RNTCP performance in tribal areas.

RESULTS

We observed a poor performance in terms of case detection rate (CDR) in tribal and backward districts as compared with other districts in India. Among tribal districts 53 per cent in 2010, 45 per cent in 2011 and 56 per cent in 2012 had CDR of new smear positive <70%. It was also observed that 26 per cent of tribal dominated districts had CDR of <51 per cent in 2012. More than 50 per cent of tribal districts were not able to achieve more than 85 per cent of cure rate.

INTERPRETATION & CONCLUSIONS

The findings of this study suggested that the overall RNTCP performance in tribal areas was not optimal, and the target of >85 per cent of core rate was achieved by less than half of the tribal districts.

Indian health care professionals' attitude towards spiritual healing and its role in alleviating stigma of psychiatric services

Persons with mental illnesses in India and rest of developing world continue to consult religious/spiritual (R/S) healers or traditional, complementary and alternative medicine (TCAM) professionals prior to seeking psychiatric services that are devoid of spiritual components of care. We aim to understand TCAM and allopathic professionals' perspectives on patients' R/S needs within mental health services, cross-sectional study was conducted at five TCAM and two allopathic tertiary care hospitals in three different Indian states; 393 participants completed RSMPP, a self-administered, semi-structured survey questionnaire. Perspectives of TCAM and allopathic health professionals on role of spirituality in mental health care were compared. Substantial percentage, 43.7 % TCAM and 41.3 % allopathic, of participants believe that their patients approach R/S or TCAM practitioners for severe mental illness; 91.2 % of TCAM and 69.7 % of allopaths were satisfied with R/S healers (p = 0.0019). Furthermore, 91.1 % TCAM and 73.1 % allopaths (p = 0.000) believe that mental health stigma can be minimized by integrating with spiritual care services. Overall, 87 % of TCAM and 73 % of allopaths agreed to primary criterion variable: 'spiritual healing is beneficial and complementary to psychiatric care.' A quarter of allopaths (24.4 %) and 38 % of TCAM physicians reportedly cross-refer their grieving patients to religious/TCAM healer and psychiatrist/psychologist, respectively; on logistic regression, significant (p < 0.05) predictors were clinical interactions/references to r/s healers. Providing spiritual care within the setup of psychiatric institution will not only complement psychiatric care but also alleviate stigma against mental health services. Implications on developing spiritual care services like clinical chaplaincy are discussed.

SMAR1 coordinates HDAC6-induced deacetylation of Ku70 and dictates cell fate upon irradiation

Acetylation status of DNA end joining protein Ku70 dictates its function in DNA repair and Bax-mediated apoptosis. Despite the knowledge of HDACs and HATs that are reported to modulate the acetylation dynamics of Ku70, very little is known about proteins that critically coordinate these key modifications. Here, we demonstrate that nuclear matrix-associated protein scaffold/matrix-associated region-binding protein 1 (SMAR1) is a novel interacting partner of Ku70 and coordinates with HDAC6 to maintain Ku70 in a deacetylated state. Our studies revealed that knockdown of SMAR1 results in enhanced acetylation of Ku70, which leads to impaired recruitment of Ku70 in the chromatin fractions. Interestingly, ionizing radiation (IR) induces the expression of SMAR1 and its redistribution as distinct nuclear foci upon ATM-mediated phosphorylation at serine 370. Furthermore, SMAR1 regulates IR-induced G2/M cell cycle arrest by facilitating Chk2 phosphorylation. Alternatively, SMAR1 provides radioresistance by modulating the association of deacetylated Ku70 with Bax, abrogating the mitochondrial translocation of Bax. Thus, we provide mechanistic insights of SMAR1-mediated regulation of repair and apoptosis via a complex crosstalk involving Ku70, HDAC6 and Bax.

2-Phenylindole and Arylsulphonamide: Novel Scaffolds Bactericidal against Mycobacterium tuberculosis

A cellular activity-based screen on Mycobacterium tuberculosis (Mtb) H37Rv using a focused library from the AstraZeneca corporate collection led to the identification of 2-phenylindoles and arylsulphonamides, novel antimycobacterial scaffolds. Both the series were bactericidal in vitro and in an intracellular macrophage infection model, active against drug sensitive and drug resistant Mtb clinical isolates, and specific to mycobacteria. The scaffolds showed promising structure-activity relationships; compounds with submicromolar cellular potency were identified during the hit to lead exploration. Furthermore, compounds from both scaffolds were tested for inhibition of known target enzymes or pathways of antimycobacterial drugs including InhA, RNA polymerase, DprE1, topoisomerases, protein synthesis, and oxidative-phosphorylation. Compounds did not inhibit any of the targets suggesting the potential of a possible novel mode of action(s). Hence, both scaffolds provide the opportunity to be developed further as leads and tool compounds to uncover novel mechanisms for tuberculosis drug discovery.

Perspectives of Indian traditional and allopathic professionals on religion/spirituality and its role in medicine: basis for developing an integrative medicine program

Allopathic medical professionals in developed nations have started to collaborate with traditional, complementary, and alternative medicine (TCAM) to enquire on the role of religion/spirituality (r/s) in patient care. There is scant evidence of such movement in the Indian medical community. We aim to understand the perspectives of Indian TCAM and allopathic professionals on the influence of r/s in health. Using RSMPP (Religion, Spirituality and Medicine, Physician Perspectives) questionnaire, a cross-sectional survey was conducted at seven (five TCAM and two allopathic) pre-selected tertiary care medical institutes in India. Findings of TCAM and allopathic groups were compared. Majority in both groups (75% of TCAM and 84.6% of allopathic practitioners) believed that patients' spiritual focus increases with illness. Up to 58% of TCAM and allopathic respondents report patients receiving support from their religious communities; 87% of TCAM and 73% of allopaths believed spiritual healing to be beneficial and complementary to allopathic medical care. Only 11% of allopaths, as against 40% of TCAM, had reportedly received 'formal' training in r/s. Both TCAM (81.8%) and allopathic (63.7%) professionals agree that spirituality as an academic subject merits inclusion in health education programs (p = 0.0003). Inclusion of spirituality in the health care system is a need for Indian medical professionals as well as their patients, and it could form the basis for integrating TCAM and allopathic medical systems in India.

Impact of sputum quality and quantity on smear and culture positivity: findings from a tuberculosis prevalence study in central India

BACKGROUND

The objective of this study was to assess the impact of sputum quality and quantity on smear and culture positivity for Mycobacterium tuberculosis.

METHODS

A total of 14 708 sputum specimens, collected from respiratory symptomatics in a TB prevalence survey, were evaluated for gross appearance and volume of sputum and examined by smear microscopy and culture.

RESULTS

The smear and culture positivity increased with the quantity and the up gradation in quality of sputum, and the difference was significant.

CONCLUSION

The study highlights the importance of visual screening of sputum specimens in the detection of pulmonary TB particularly in resource limited settings.

Methyl-thiazoles: a novel mode of inhibition with the potential to develop novel inhibitors targeting InhA in Mycobacterium tuberculosis

InhA is a well validated Mycobacterium tuberculosis (Mtb) target as evidenced by the clinical success of isoniazid. Translating enzyme inhibition to bacterial cidality by targeting the fatty acid substrate site of InhA remains a daunting challenge. The recent disclosure of a methyl-thiazole series demonstrates that bacterial cidality can be achieved with potent enzyme inhibition and appropriate physicochemical properties. In this study, we report the molecular mode of action of a lead methyl-thiazole, along with analogues with improved CYP inhibition profile. We have identified a novel mechanism of InhA inhibition characterized by a hitherto unreported "Y158-out" inhibitor-bound conformation of the protein that accommodates a neutrally charged "warhead". An additional novel hydrophilic interaction with protein residue M98 allows the incorporation of favorable physicochemical properties for cellular activity. Notably, the methyl-thiazole prefers the NADH-bound form of the enzyme with a Kd of ~13.7 nM, as against the NAD(+)-bound form of the enzyme.

Generation of soluble NKG2D ligands: proteolytic cleavage, exosome secretion and functional implications

The activating natural killer group 2 member D (NKG2D) receptor is expressed on NK cells, cytotoxic T cells and additional T cell subsets. Ligands for human NKG2D comprise two groups of MHC class I-related molecules, the MHC class I chain-related proteins A and B (MICA/B) and 6 UL16-binding proteins (ULBP1-6). While NKG2D ligands are absent from most normal cells, expression is induced upon stress and malignant transformation. In fact, most solid tumours and leukaemia/lymphomas constitutively express at least one NKG2D ligand and thereby are susceptible to NKG2D-dependent immunosurveillance. However, soluble NKG2D ligands are released from tumour cells and can down-modulate NKG2D activation as a means of tumour immune escape. In some tumour entities, levels of soluble NKG2D ligands in the serum correlate with tumour progression. NKG2D ligands can be proteolytically shed from the cell surface or liberated from the membrane by phospholipase C in the case of glycosylphosphatidylinositol (GPI)-anchored molecules. Moreover, NKG2D ligands can be secreted in exosomal microvesicles together with other tumour-derived molecules. Depending on the specific tumour/immune cell setting, these various forms of soluble and/or exosome-bound NKG2D ligands can exert multiple effects on NKG2D/NKG2D ligand interactions. In this review, we focus on the role of various proteases in the shedding of human NKG2D ligands from tumour cells and discuss the not completely unanimous reported functional implications of soluble and exosome-secreted NKG2D ligands for immunosurveillance.

LC-MS based assay to measure intracellular compound levels in Mycobacterium smegmatis: linking compound levels to cellular potency

Dihydrofolate reductase (DHFR) plays a central role in maintaining cellular pool of tetrahydrofolic acid, a cofactor necessary for DNA, RNA and protein synthesis. The clinical validation of DHFR as antibacterial target was established by the success of trimethoprim (TMP). DHFR is also an attractive target for identifying anti-tuberculosis molecules however, due to observed weak cellular potency, no DHFR inhibitors have been developed as drugs so far. TMP and its analogs have poor cellular potency on Mycobacterium tuberculosis and Mycobacterium smegmatis cells. We found a mutant strain of M. smegmatis, mc²155 to be sensitive to TMP whereas wild type strain was not inhibited by TMP. We utilized this system to probe if poor or lack of activity of TMP is a consequence of poor intracellular compound levels. An LC-MS based method was developed for measuring TMP and rifampicin (RIF) in M. smegmatis. Using the assay, equivalent RIF levels were observed in both strains however, TMP was detected only in mc²155 cells, hence proving a positive correlation between potency and compound levels. To the best of our knowledge this is the first time LC-MS method has been used to measure compound levels in mycobacterial cells. We propose it to be a valuable tool to understand the lack of potency or resistance mechanisms in antimycobacterial drug development.

Knowledge and attitude towards tuberculosis amongst the tribal population of Jhabua, Madhya Pradesh

A community-based cross-sectional survey was carried out amongst the tribal population of Jhabuain Madhya Pradesh. A total of 1385 individuals from randomly selected villages were interviewed using structured questionnaire. Eighty five per cent respondents had knowledge of the symptoms of tuberculosis. About a quarter of the respondents were not aware of any method for preventing TB. Though majority of the respondents (68.2%) stated that TB is a curable disease, most of them (67.2%) were not aware of the DOTS programme. The study emphasizes the need for extensive health education programme to create awareness about tuberculosis in tribal population of the region.

Prevalence of pulmonary tuberculosis--a baseline survey in central India

Background

The present study provides an estimate of the prevalence of bacteriologially positive pulmonary tuberculosis in Jabalpur, a district in central India.

Methodology/Principal Findings

A community based cross-sectional survey was undertaken in Jabalpur District of the central Indian state of Madhya Pradesh. A stratified cluster sampling design was adopted to select the sample. All eligible individuals were questioned for pulmonary symptoms suggestive of TB disease. Two sputum samples were collected from all eligible individuals and were examined by Ziehl-Neelsen smear microscopy and solid media culture methods. Of the 99,918 individuals eligible for screening, 95,071 (95.1%) individuals were screened. Of these, 7,916 (8.3%) were found to have symptoms and sputum was collected from 7,533 (95.2%) individuals. Overall prevalence of bacteriologically positive PTB was found to be 255.3 per 100,000 population (95% C.I: 195.3–315.4). Prevalence was significantly higher (p<0.001) amongst males (355.8; 95% C.I: 304.4–413.4) compared with females (109.0; 95% C.I: 81.2–143.3). Prevalence was also significantly higher in rural areas (348.9; 95% C.I: 292.6–412.8) as compared to the urban (153.9; 95% C.I: 123.2–190.1).

Conclusions/Significance

The TB situation in Jabalpur district, central India, is observed to be comparable to the TB situation at the national level (255.3 versus 249). There is however, a need to maintain and further strengthen TB control measures on a sustained and long term basis in the area to have a significant impact on the disease prevalence in the community.

Screening, identification, and characterization of mechanistically diverse inhibitors of the Mycobacterium tuberculosis enzyme, pantothenate kinase (CoaA)

The authors describe the discovery of anti-mycobacterial compounds through identifying mechanistically diverse inhibitors of the essential Mycobacterium tuberculosis (Mtb) enzyme, pantothenate kinase (CoaA). Target-driven drug discovery technologies often work with purified enzymes, and inhibitors thus discovered may not optimally inhibit the form of the target enzyme predominant in the bacterial cell or may not be available at the desired concentration. Therefore, in addition to addressing entry or efflux issues, inhibitors with diverse mechanisms of inhibition (MoI) could be prioritized before hit-to-lead optimization. The authors describe a high-throughput assay based on protein thermal melting to screen large numbers of compounds for hits with diverse MoI. Following high-throughput screening for Mtb CoaA enzyme inhibitors, a concentration-dependent increase in protein thermal stability was used to identify true binders, and the degree of enhancement or reduction in thermal stability in the presence of substrate was used to classify inhibitors as competitive or non/uncompetitive. The thermal shift-based MoI assay could be adapted to screen hundreds of compounds in a single experiment as compared to traditional biochemical approaches for MoI determination. This MoI was confirmed through mechanistic studies that estimated K(ie) and K(ies) for representative compounds and through nuclear magnetic resonance-based ligand displacement assays.

Yield of culture of Mycobacterium tuberculosis complex in sputum samples transported from tribal areas

BACKGROUND

There is little information on the recovery of Mycobacterium tuberculosis complex from sputum samples collected in the field for bacteriological examination.

SETTING

Tribal areas in the State of Madhya Pradesh, in central India.

METHODS

Sputum specimens collected from subjects with chest symptoms in a disease prevalence survey were refrigerated until transportation to the laboratory. The specimens were processed for microscopy and culture. The samples were grouped based on the delay in processing for culture from the day of collection into three groups: 0-3, 4-7 and ≥8 days, and the recovery of M. tuberculosis complex in these groups was analysed. The statistical analysis was performed using χ(2) test.

RESULTS

Of the 3651 processed specimens, 114 were positive for M. tuberculosis complex by culture and 96 by smear microscopy. The differences in the proportion of 'smear-positive, culture-positive', 'smear-positive, culture-negative' and 'smear-negative, culture-positive' samples between the three groups were not significant.

CONCLUSION

In difficult-to-reach areas with limited resources, refrigeration of sputum specimens until they are transported for processing at a reference laboratory for culture seems not to significantly affect the recovery of M. tuberculosis complex isolates.