Tuberculosis control in India: Refocus on nutrition

Computational design of MmpL3 inhibitors for tuberculosis therapy

Tuberculosis is a chronic communicable disease caused by Mycobacterium tuberculosis (Mtb) and spreads from lungs to lymphatic system. The cell wall of mycobacterium plays a prominent role in maintaining the virulence and pathogenicity and also acts as prime target for drug discovery. Hence, this study has put into emphasis with target MmpLs (Mycobacterial membrane proteins Large) which are significant for the growth and survival of Mycobacterium tuberculosis. MmpLs belongs to the resistance, nodulation and division (RND) protein superfamily. MmpL3 is the only MmpL deemed essential for the replication and viability of mycobacterial cells. For the study, we have selected SQ109 derivatives as Mmpl3 inhibitor, which holds non-covalent property. Structure-based pharmacophore model of MmpL3 target protein with SQ109 as co-crystallized ligand (PDB: 6AJG) was generated to screen the ligand database. Compounds with decent fitness score and pharmacophoric features were compared with standard drug and taken for molecular docking studies. Further prime molecular mechanics-Poisson-Boltzmann surface area (MM-GBSA) and induced fit calculations identified potential molecules for further drug-likeness screening. Overall computational calculations identified ZINC000000016638 and ZINC000000003594 as potential in silico MmpL3 inhibitors. Molecular dynamics simulations integrated with MM-PBSA free energy calculations identified that MmpL3-ZINC000000016638 complex was more stable. Study can be further extended for synthesis and biological evaluation, derivatization of active compound to identify potential and safe lead compounds for effective tuberculosis therapy.

Prevalence and risk factors associated with latent tuberculosis infection among household contacts of smear positive pulmonary tuberculosis patients in South India

OBJECTIVE

We aimed to determine the prevalence and find the risk factors associated with latent tuberculosis infection (LTBI) among the household contacts (HHC) of pulmonary TB patients.

METHODS

This cohort study was conducted from 2014 to 2019. Pretested standardised questionnaires and tools were used for data collection. The prevalence of LTBI among HHCs of TB patients was summarised as proportion with 95% confidence interval (CI). Mixed-effects generalised linear modelling function (meglm) in STATA with family Poisson and log link was performed to find the factors associated with LTBI.

RESULTS

In total, 1523 HHC of pulmonary TB patients were included in the study. Almost all HHC shared their residence with the index case (IC) for more than a year; 25% shared the same bed with the IC. The prevalence of LTBI among the HHC of TB patients was 52.6% (95% CI: 50.1-55.1%). In an adjusted model, we found that among HHC belonging to the age group of 19-64 years (aIRR = 1.2; 95% CI: 1.1-1.3; p-value: 0.02), to the age group >65 years (aIRR = 1.4, 95% CI: 1.1-1.9, p-value: 0.02) and sharing the same bed with the IC (aIRR = 1.2, 95% CI: 1.1-1.3, p value: 0.04) were independent determinants of LTBI among the HHC.

CONCLUSION

One in two household contacts of TB patients have latent tuberculosis infection. This underscores the need of targeted contact screening strategies, effective contact tracing and testing using standardised methods in high TB burden settings.

Modeling and analysis of barriers in controlling TB: developing countries' perspective

Purpose

Tuberculosis (TB) continues to c-exist with humans despite many TB control programs and elimination strategies. This depicts that some barriers are not allowing achieving the desired results. The current study aims to focus on identification and ranking of such barriers to facilitate TB control programs in developing countries.

Design/methodology/approach

In the present study, 13 barriers that can influence success rate of TB elimination strategies have been recognized with an in-depth assessment of related literature and opinions of specialists from medical industry and academic world. The interpretive structural modeling (ISM) and decision-making trial and evaluation laboratory (DEMATEL) techniques have been employed for the ranking of barriers.

Findings

Based on driving power of barriers, the study coined that underinvestment is a major barrier followed by poor implementation of government policies and programs, poverty and poor primary health care infrastructure.

Research limitations/implications

The findings may guide healthcare service providers and researchers in analyzing the barriers and understanding the necessity of further advancements to decrease the count of already existing and incident cases.

Practical implications

Policy- and decision-makers may utilize the information on dependence and driving power of barriers for better planning and effective execution of TB control strategies.

Originality/value

Although a lot of literature is available on different barriers that are affecting success of TB strategies, the current study analyzes all the key barriers collectively for the prioritization of barriers.

Determinants of drug resistant & drug sensitive tuberculosis patients from North India-a case control study

BACKGROUND AND OBJECTIVE

The burden of drug resistant tuberculosis (DRTB) has posed a huge challenge to for the governments, throughout the world. India has 27% of the global DRTB burden with incidence of 130,000 cases. India has kept an ambitious target of elimination of tuberculosis by 2025 which requires understanding and mitigating various determinants of DRTB.

METHODS

The retrospective case control study was undertaken from May to September 2019 among drugresistant (cases) and drug sensitive (controls) tuberculosis patients from two districts of Himachal Pradesh, India. A total of 211 participants were recruited in the study, which includes all 102 cases and randomly selected, age and sex matched 109 controls. A semi structured questionnaire, adapted from a study by Lobo et al, was used for assessing the determinants of DRTB and DSTB. The data collection was undertaken from district and block level health care facilities followed by home visits to patients. Multivariate logistic regression was used to determine risk factors associated with DRTB.

RESULTS

Diagnostic delay (aOR-7.72, p value 0.000), history of treatment default (aOR-2.97, self history of tuberculosis (aOR 1.42, p value 0.01), migration (aOR-4.84, p value 0.000), smoking (aOR-2.70, p value 0.014), and belonging to rural area (aOR-2.62, p value- 0.013) were found as independent risk factors for the occurrence of DRTB.

CONCLUSION

The risk factors identified in the study should be prioritized by the policy makers, implementators and educators for framing appropriate policies in TB control programme in India. The diagnostic delay as a risk factor merits active case finding of TB patients and educating health care staff and community.

Prevalence and determinants of TB infection in a rural population in northeastern Myanmar

BACKGROUND

Tuberculosis (TB) is a major human threat, as evidenced by the large numbers of cases and deaths, particularly in developing countries with poor economic and educational statuses. Myanmar has one of the highest TB burdens in the world, but no TB information is available for people living in the rural northeastern regions of Myanmar. The present study estimated the prevalence of TB and identified factors associated with TB infection in people living in rural communities in Shan State.

METHODS

A cross-sectional study was performed to gather information from participants. People aged 18-59 years who lived in the three areas with the highest numbers of TB cases in Shan State in northeastern Myanmar were included in the study population. A simple random method was used to select the sample from the villages. A validated questionnaire was used for data collection in face-to-face interviews after obtaining signed informed consent from the selected participants. The Mantoux tuberculin skin test (TST) was administered to detect TB infection, and a result that was 10 mm or greater after 48 h was considered positive. Chi-squared tests and logistic regression were used to identify the associations between the variables at a significance level of α = 0.05.

RESULTS

A total of 303 participants were recruited for the study; 64.7% were females, and the mean age was 37 years (SD = 12.5). Most participants were Burmese (25.4%), and 14.95% were Shan. Sixty-three participants (20.8%) had a positive TST. Four variables were associated with TB infection in the multivariate model. Males had a greater chance of TB infection than females (AOR = 2.51; 95% CI = 1.32-4.76). Participants who were ever married had a greater chance of TB infection than participants who were single (AOR = 3.93; 95% CI = 1.18-13.00). Participants who used wood and charcoal as their main sources of energy for cooking had a greater chance of TB infection than participants who used electricity (AOR = 4.23; 95% CI = 1.25-9.64). Participants who had a low level of TB prevention and care knowledge had a greater chance of TB infection than participants with a high level of TB prevention and care knowledge (AOR = 4.49; 95% CI = 1.88-10.72).

CONCLUSIONS

Public health programs that focus on improving knowledge of TB prevention and care and avoiding the use of wood and charcoal as the primary sources of energy for cooking, particularly in males and ever-married individuals, are urgently needed.

The potential impact of the COVID-19 response related lockdown on TB incidence and mortality in India

India has the highest burden of incident tuberculosis (TB) cases and deaths globally. TB is strongly associated with poverty and this risk is largely mediated by undernutrition in India. COVID-19 response related lockdown has resulted in an economic crisis which may double levels of poverty, has exacerbated food insecurity, and disrupted TB services. These developments may have serious implications for TB progression and transmission in India. The nutritional status of a population is a strong determinant of the TB incidence, and undernutrition in adults alone accounts for 32-44% of TB incidence in India. A systematic review has shown that a 14% increase in TB incidence can occur per one unit decrease in body mass index (BMI), across the BMI range of 18.5-30 kg/m2. We believe that one unit decrease in BMI (corresponding to a 2-3 kg weight loss) may result in the poor in India as a result of the lockdown and its aftermath. This may result in an increase in estimated (uncertainty interval) incident TB by 185 610 (180 230, 190 990) cases. A 59% reduction in TB case detection between end March and May 2020, may result in an estimated (uncertainty interval) additional 87 711 (59 998, 120 630) TB deaths [19.5% increase (14.5, 24.7)] in 2020. Disadvantaged social groups and those living in states with higher levels of poverty, under-nutrition,and migrant workers are at particular risk. We suggest enhanced rations including pulses through the public distribution system and direct cash transfers to the poor pending restoration of livelihoods. TB services should be resumed immediately with enhanced efforts at case detection including active case finding. To prevent deaths among TB detected within the national TB programme, systemic identification, referral and management of severe disease at notification should be considered.

Improvement of Nutritional Status among Tuberculosis Patients by Channa striata Supplementation: A True Experimental Study in Indonesia

OBJECTIVE

To analyze the effect of Channa striata supplementation on body mass index among tuberculosis patients, in which their health status is also investigated.

METHODS

This study employed a true experiment. The study was designed randomized pretest-posttest with a control group, in which 200 respondents were enrolled. Body mass index (BMI), used as a nutritional status indicator, was measured every week for a month. Chi-square test was used to analyze the data with a significance level of 5% by STATA 13.

RESULTS

The mean BMI of all groups increases during the month, in which rapid alteration occurs in the treatment group. The mean BMI (kg/m2) in the treatment group at weeks 0-4 was reported to be 17.43, 17.65, 17.90, 18.04, and 18.22, respectively. Meanwhile, the mean BMI (kg/m2) at weeks 0-4 in the control group was reported to be 17.20, 17.36, 17.57, 17.71, and 17.96, respectively. Furthermore, the alteration from severe thinness to higher BMI level in the treatment group is the highest. Based on the statistical test, there were no differences in BMI between the treatment and control groups (p > 0.05). However, the alteration of nutritional status in the treatment group is faster than that in the control group. In addition, there is no difference in their health status between the treatment and control groups (p > 0.05), except vomiting (p < 0.05).

CONCLUSION

The BMI among tuberculosis patients with Channa striata supplementation is increasing faster than that in the control group within a month with a minimum potential negative effect.