Mycobacterium tuberculosis strain lineage in mixed tribal population across India and Andaman Nicobar Island.

In India, the tribal population constitutes almost 8.6% of the nation's total population. Despite their large presence, there are only a few reports available on Mycobacterium tuberculosis (M. tb) strain prevalence in Indian tribal communities considering the mobile nature of this population and also the influence of the mainstream populations they coexist within many areas for their livelihood. This study attempts to provide critical information pertaining to the TB strain diversity, its public health implications, and distribution among the tribal population in eleven Indian states and Andaman & Nicobar (A&N) Island. The study employed a population-based molecular approach. Clinical isolates were received from 66 villages (10 states and Island) and these villages were selected by implying situation analysis. A total of 78 M. tb clinical isolates were received from 10 different states and A&N Island. Among these, 16 different strains were observed by spoligotyping technique. The major M. tb strains spoligotype belong to the Beijing, CAS1_DELHI, and EAI5 family of M. tb strains followed by EAI1_SOM, EAI6_BGD1, LAM3, LAM6, LAM9, T1, T2, U strains. Drug-susceptibility testing (DST) results showed almost 15.4% of clinical isolates found to be resistant to isoniazid (INH) or rifampicin (RMP) + INH. Predominant multidrug-resistant (MDR-TB) isolates seem to be Beijing strain. Beijing, CAS1_DELHI, EAI3_IND, and EAI5 were the principal strains infecting mixed tribal populations across India. Despite the small sample size, this study has demonstrated higher diversity among the TB strains with significant MDR-TB findings. Prevalence of Beijing MDR-TB strains in Central, Southern, Eastern India and A&N Island indicates the transmission of the TB strains.

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.

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.

Unique hepatitis B virus subgenotype in a primitive tribal community in eastern India.

Hepatitis B virus (HBV) strains isolated from members of the primitive Paharia ethnic community of Eastern India were studied to gain insight into the genetic diversity and evolution of the virus. The Paharia tribe has remained quite separate from the rest of the Indians and differs culturally, genetically, and linguistically from the mainstream East Indian population, whose HBV strains were previously characterized. Full-length HBV DNA was PCR amplified, cloned, and sequenced. Phylogenetic relationships between the tribal sequences and reference sequences from the mainstream population were assessed, and divergence times of subgenotypes of HBV genotype D were estimated. HBV was found in 2% of the Paharias participating in the study. A predominance of hepatitis B e antigen-negative infection (73%) was observed among the Paharias, and the genome sequences of the HBV strains exhibited relative homogeneity, with a very low prevalence of mutations. The novel feature of Paharia HBV was the exclusive presence of the D5 subgenotype, which was recently identified in Eastern India. Analysis of the four open reading frames (ORFs) of these tribal HBV D5 sequences and comparison with previously reported D1 to D7 sequences enabled the identification of 27 specific amino acid residues, including 6 unique ones, that could be considered D5 signatures. The estimated divergence times among subgenotypes D1 to D5 suggest that D5 was the first to diverge and hence is the most ancient of the D subgenotypes. The presence of a specific, ancient subgenotype of HBV within an ethnically primitive, endogamous population highlights the importance of studies of HBV genetics in well-separated human populations to understand viral transmission between communities and genome evolution.