Burden of Tuberculosis among tribal populations of India: A systematic review and meta-analysis

ABSTRACT

Tuberculosis (TB) continues to impose a significant burden on tribal populations in India, a high-risk group for the disease. Despite its preventable and curable nature, TB remains a formidable health challenge for these communities. However, a critical knowledge gap exists regarding the population-based prevalence of TB among tribal populations in India. The current systematic review and meta-analysis were carried out to provide a single, population-based estimate. A comprehensive search was conducted on PubMed, Embase, Scopus, and Web of Science databases using the keywords ‘tuberculosis’, ‘TB’, and ‘tribal’ or ‘tribes’. This search encompassed articles published between 1 January 2000 and 1 March 2023. The included articles underwent a quality assessment screening to ensure their reliability and relevance. Subsequently, a pooled estimate of TB prevalence among tribal populations was quantified using a random-effects model. To investigate potential sources of heterogeneity in the prevalence estimates, subgroup analyses were performed. We identified 14 studies that encompassed a substantial population of 267,377 individuals from various regions in India belonging to tribal communities. The application of a random-effects model yielded a pooled prevalence estimate of 894.4 per 100,000 population, with a 95% confidence interval ranging from 523.5 to 1361.9. The assessment of heterogeneity using the Cochrane Q test indicated significant variability among the included studies (I2 = 99.17%; P < 0.001). Notably, the prevalence of TB among tribal populations was found to be higher than the national prevalence. The scientific evidence available for the prevalence of TB among tribal populations is restricted to a few tribes only. Conducting further research to estimate the prevalence among other tribes all over the country is the need of the hour and should be addressed accordingly.

INTRODUCTION

Tuberculosis (TB) is a communicable disease, which is a major cause of ill health and one of the leading causes of death worldwide.[1] A total of 1.6 million people died from TB in 2021 (including 187,000 people with HIV). Worldwide, TB is the 13^th leading cause of death and the second leading infectious killer after COVID-19 (above HIV and AIDS). In 2021, an estimated 10.6 million people fell ill with TB worldwide, of which 6 million were men, 3.4 million women, and 1.2 million were children.[2] As per the Global TB Report 2021, the estimated incidence of all forms of TB in India for 2020 was 188 per 100,000 population (129-257 per 100,000 population). The total number of incident TB patients (new and relapse) notified during 2021 was 19,33,381.[3]

The tribal population is considered to be a high-risk group for TB. As per the Census 2011, the tribal population constitutes around 8.9%, that is, 10.43 crore of the total population in India.[4,5] Numerically, Madhya Pradesh has the largest tribal population (15 million), followed by Maharashtra (10 million), Odisha (9 million) and Rajasthan (9 million).[6] There are gaping disparities in the health status of the tribal population compared with the general population. Diverse tribal groups are prevalent in India; however, they share some common characteristics when the health perspectives of these tribes are compared. The commonality among these tribes is that they have poor health indicators, which also suggests a greater burden of morbidity and mortality, as there is very limited access to healthcare services.[6]

There is almost near complete absence of data when it comes to tribal health.[6] The absence of a composite picture of tribal health in India also suggests that there are no estimates available regarding the prevalence of TB, contributed by the tribal population of India. While recommendations for new interventions are usually based on evidence from the general population, little is known about the tribal areas. Therefore, with the objective of determining a population-based estimate of TB in the tribal population of India, this systematic review and meta-analysis was conducted.

Research question and selection criteria

We conducted a systematic review using the population, intervention, comparator, outcome (PICO) criteria [Annexure 1] to investigate the prevalence of TB among tribal populations in India. Our inclusion criteria were community-based TB prevalence studies that included individuals aged 15 years and older from tribal communities and conducted initial screening for standard TB symptoms, such as cough for > 2 weeks, fever for > 2 weeks, chest pain, and haemoptysis. We have included studies where sputum samples were collected and either smear (for acid-fast bacilli, AFB) or culture tests were done, and a positive TB case was defined as positive by either smear or culture. Only studies reporting TB prevalence based on smear and/or culture results were included. We registered our study in the International Prospective Register of Systematic Reviews as CRD42023386767.

Annexure 1.

Inclusion and exclusion criteria as per PICOS [Research Question: What is the prevalence of pulmonary tuberculosis among tribal population of India?]

Inclusion		Exclusion
Participants	Tribal population with confirmed pulmonary TB (diagnosed only by sputum AFB and sputum culture)  • All gender  • Age more than 15 years	Diagnosis of pulmonary TB diagnosed based only on symptoms or chest X-ray
Intervention	NA
Comparison	NA
Outcome	Prevalence of TB
Study designs	Prevalence studies, cross-sectional studies	Case reports, RCTs

Databases included and search strategy

To identify relevant studies, we searched PubMed, Scopus, Embase, and Web of Science databases from 1 January 2000 to 31 March 2023 using the keywords ‘tuberculosis’, ‘TB’, and ‘tribal’ or ‘tribes’. Medical subject headings (MeSH) terms with asterisks were used to refine the search. Additionally, we searched the reference lists of the included papers and other reviews to identify any new eligible studies [see Annexure 2]. We managed the citations, removed duplicates, and coordinated the review process using Mendeley Desktop V1.19.5 software. The primary outcome of interest was the prevalence of TB among the tribal populations in India, which we estimated using summary statistics.

Annexure 2.

The adjusted search terms as per searched electronic databases [as of 12.03.2023]

Database	No.	Search Query	Results
EMBASE
	1	((tuberculosis: ti, ab) OR (TB: ti, ab))	281496
	2	(((tribe: ti, ab) OR (tribal: ti, ab)) OR (tribes: ti, ab))	15792
	3	#1 AND #2 AND [english]/lim AND [2000-2023]/py	208
PubMed
	1	"trib*"[Title/Abstract] OR "Tribal"[Title/Abstract] OR "Tribes"[Title/Abstract]	51985
	2	"Tuberculosis"[Title/Abstract] OR "TB"[Title/Abstract]	257594
	3	1 AND 2 AND (2000:2023[pdat])	298
Scopus
	1	((TITLE-ABS (Tuberculosis)) OR (TITLE-ABS (TB))	413,627
	2	(((TITLE-ABS (tribal)) OR (TITLE-ABS (tribe)) OR (TITLE-ABS (tribes)))	50,782
	3	#1 AND #2 AND (English[Filter] )	285
Web of Science
	1	(((TI=Tuberculosis OR AB=Tuberculosis)) OR ((TI=TB OR AB=TB)))	178764
	2	((((((TI=tribe OR AB=tribe)) OR ((TI=tribal OR AB=tribal))) OR ((TI=tribes OR AB=tribes)))	23284
	3	#1 AND #2 AND (English[Filter] )	116

Screening of studies

Title abstract screening

Two independent authors (AD and NS) reviewed the title abstracts of the studies obtained from the above systematic search by applying the eligibility criteria and identified articles for full-text screening. If there was a disagreement regarding the inclusion of a study for full-text review, the co-authors conversed among themselves to build a consensus and decided on eligibility. If there was still a conflict between the co-authors regarding the eligibility of the publication, a third co-author (SG) was consulted to assess the title abstracts, and she decided whether to include the study for full-text review.

Full-text screening and data extraction

Two independent authors (AD and NS) reviewed potentially eligible full-text articles for suitability and extracted data from these articles. In case of disagreement at any step, the authors conversed among themselves to reach a consensus. The third author (SG) decided on unresolved contradictions. The final data extraction table was prepared in a Microsoft Excel spreadsheet for further analysis. The following information was gathered from each of the final eligible articles: author’s name, place where the study was conducted, year of publication, study design, number of positive cases, and total sample size, with a focus on capturing the prevalence of TB among the tribal population. The whole process of literature search, screening, data extraction, systematic review, and meta-analysis was performed using the Preferred Reporting Standard of Systematic Reviews and Meta-Analysis (PRISMA-2020) flowchart.

Quality assessment

Two independent authors (AD and NS) assessed the risk of bias in the included studies using quality assessment tools recommended by the Joanna Briggs Institute (JBI) critical appraisal tool for prevalence studies.

Statistical analysis

The prevalence of TB was determined by dividing the number of patients with positive smear or culture results by the total number of study participants. Prevalence is presented as the number of pulmonary TB cases per 100,000 individuals. We calculated the pooled prevalence and 95% confidence intervals (95% CIs) using a random effects model based on the DerSimonian and Laird methods. The Chi-square-based Q statistic and I2 test were used to assess between-study heterogeneity, with two-sided P values. To address the risk of bias, we conducted a sensitivity analysis by excluding poor-quality studies. We also performed three subgroup analyses to identify the source of heterogeneity: i) gender, ii) age groups, iii) state of study (Madhya Pradesh vs. other states), iv) year of publication (2000-2010 vs. 2011-2022), and v) method of testing (only sputum AFB or sputum AFB along with culture). We used a funnel plot to assess publication bias. The Egger test was used to evaluate the small study effects. Statistical significance was set at P < 0.05. We conducted the meta-analysis using STATA® software (version 18, STATA Corp.).

Role of the funding source

The authors have no funding sources available for this study. All authors had full access to all data in the study and had the final responsibility for the decision to submit for publication.

Ethical statement

An ethical review is not applicable to this study because it uses data available in the published literature.

RESULTS

A systematic search was performed, and 914 articles were identified. Of these, 573 duplicates were removed. After screening the titles and abstracts of the remaining 341 articles, 304 articles were deemed ineligible and excluded. Full-text screening was performed on the remaining 37 articles, and after careful consideration, 20 articles were eliminated for various reasons, such as not meeting eligibility criteria, having different study designs, or incorrect outcomes. In addition, three articles used different methodologies. Finally, 14 studies were eligible for inclusion in the systematic review. A study conducted by Rao et al. had prevalence measured at different times, so both the prevalence was taken and was considered as two different studies.[7] The entire process of article review and selection was depicted using the PRISMA flow chart [Figure 1].

Figure 1.

PRISMA flowchart

The studies were conducted between January 2000 and March 2023, and the baseline characteristics were obtained from cross-sectional surveys or studies, which are summarized in Table 1. Most of the studies were conducted in Madhya Pradesh (9; 69.2%). The sample sizes for the studies ranged from 1390 (Rao et al.) to 74,532 (Thomas et al.).[8,9] The lowest prevalence of pulmonary TB was reported in Dindori district of Madhya Pradesh at 84.8 cases per lakh population, while the highest prevalence was found in Jabalpur district in Madhya Pradesh at 3294.3 cases per lakh population.[10,11] In our study, 10 studies used sputum culture along with sputum AFB as a diagnostic method, whereas four studies used only sputum AFB as a diagnostic method.

Table 1.

Characteristics of studies included in the meta-analysis

Author	Year of the study	Tribal population details	Place of study	Period of study	Sample size	Pulmonary TB prevalence (per 100,000) among			Methodology
						Males	Females	Both
Datta et al.[12]	2001	Malayali	North Arcot district of Tamil Nadu	1989	16,017	1,220	440	840	Sequential screening of whole population, with TB symptoms followed by chest X-ray, followed by sputum smear examination and culture.
Murhekar et al.[13]	2004	Mongloloids	Car Nicobar of Andaman and Nicobar	2001-2002	10,570	-	-	728.5	Screening of whole population, with TB symptoms, followed by sputum smear examination.
Bhat et al.[14]	2009	Saharia and other tribes	Ten Districts of Madhya Pradesh	2007-2008	23,411	554	233	387	Screening of selected population (cluster sampling), with TB symptoms, followed by sputum smear examination and culture
Rao et al.[9]	2009	Bharia	Madhya Pradesh	2008	1,390	-	-	432	Screening of whole population, with TB symptoms, followed by sputum smear examination and culture.
Yadav et al.[11]	2010	Baigas	Dindori district of Madhya Pradesh	2008	2,359	-	-	146	Screening of selected population (random sampling), with TB symptoms, followed by sputum smear examination and culture.
Rao et al.[15]	2010	Saharia	Sheopur district of Madhya Pradesh	2007-2008	11,468	2,156	933	1,518	Screening of selected population (random sampling), with TB symptoms, followed by sputum smear examination and culture.
Rao et al.[10]	2015	Saharia	Gwalior district of Madhya Pradesh	2012-2013	9,653	5,497	1,376	3,294	Screening of selected population (cluster sampling), with TB symptoms, followed by sputum smear examination and culture.
Purty et al.[16]	2019	-	Ahmadnagar, Dhule, Nashik, and Nandurbar district of Maharashtra	2015-2017	6,896	1,739	87	261	Screening of selected population (cluster sampling), with TB symptoms, followed by sputum smear examination.
Rao et al.[7]	2019	Saharia	Madhya Pradesh	2015	9,775	1,246	906	1,995	Screening of selected population (cluster sampling), with TB symptoms, followed by sputum smear examination and culture.
Rao et al.[7]	2019	Saharia	Madhya Pradesh	2013	9,756	4,832	3,170	3,003
Vyas et al.[17]	2019	Saharia	Gwalior district of Madhya Pradesh	2014-2015	65,230	-	-	1,478	Screening of whole population, with TB symptoms, followed by sputum smear examination.
Hussain et al.[18]	2020	-	Balangir district of Odisha	2015-2017	5,144	-	-	681	Screening of whole population, with TB symptoms, followed by sputum smear examination and culture.
Krishna et al.[19]	2020	Malayali, Irular and Kurumbar	Villupuram, Namakkal and Nilgiri district of Tamil Nadu	-	2,553	-	-	196	Screening of selected population (cluster sampling), with TB symptoms, followed by sputum smear examination.
Bhat et al.[20]	2021	Saharia	Gwalior and Chambal district of Madhya Pradesh	2019	20,114	-	-	1,357	Screening of selected population (cluster sampling), with TB symptoms, followed by sputum smear examination and culture.
Thomas et al.[21]	2021		17 states of India	2015-2020	74,532			199	Screening was done after multistage sampling, and chest symptomatic patients were followed by sputum smear examination and culture.

A meta-analysis was conducted to determine the prevalence of pulmonary TB among the tribal population of 2,67,377 individuals in the included studies. Among them, 2754 were positive for pulmonary TB. The pooled estimate, based on the random effects model, was 894.4 per 100,000 population with a 95% CI of 523.5-1361.9. We used the Freeman–Tukey transformation. We performed the Cochrane Q test to detect heterogeneity. The Cochrane q-test was positive for heterogeneity (P < 0.01). The heterogeneity was high in the current meta-analysis (I² = 99.17%; P < 0.001) [Figure 2].

Figure 2.

Forest plot of meta-analysis of the TB prevalence among tribal populations in India

The quality assessment of the 14 included studies is provided in the supplementary File 1. Of these, 12 were rated as fair or good quality. Two of the studies were of moderate quality. By removing two studies from the analysis, the pooled prevalence was 994.5 [95% CI 562.65–1545.6] [Supplementary 2 ^{(133.3KB, tif)} ].

Supplementary File 1.

Assessment of quality of studies according to JBI tool for prevalence studies

Author	JBI Tool Items									Score
	1. Was the sample frame appropriate to address the target population?	2.Were study participants sampled in an appropriate way?	3. Was the sample size adequate?	4. Were the study subjects and the setting described in detail?	5. Was the data analysis conducted with sufficient coverage of the identified sample?	6. Were valid methods used for the identification of the condition?	7. Was the condition measured in a standard, reliable way for all participants?	8. Was there appropriate statistical analysis?	9. Was the response rate adequate, and if not, was the low response rate managed appropriately?
Datta et al.[12]	✓	✓	(CE)	✓		✓	✓	?	✓	6	Moderate
Murhekar et al.[13]	✓	✓	(CE)	✓	✓	✓	✓	✓	?	7	Good
Bhat et al.[14]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good
Rao et al.[9]	✓	✓	(CE)	✓	✓	✓	✓	✓	✓	8	Good
Yadav et al.[11]	✓		?	✓	?	✓	✓	✓	?	5	Moderate
Rao et al.[15]	✓	✓	(CE)	✓	✓	✓	✓	✓	✓	8	Good
Rao et al.[10]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good
Purty et al.[16]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good
Rao et al.[7]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good
Vyas et al.[17]	✓	✓	(CE)	✓	✓	✓	✓	✓	?	7	Good
Hussain et al.[18]	✓	✓	✓	✓	✓	✓	✓	✓	?	8	Good
Krishna et al.[19]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good
Bhat et al.[20]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good
Thomas et al.[21]	✓	✓	✓	✓	✓	✓	✓	✓	✓	9	Good

Symbols used in the above table symbolizes as: ✓=Yes, = No, ?= Unclear, =Not applicable CE: Complete Enumeration Score: 1-3 = Poor quality 4-6 = Moderate quality 7-9 = Good quality

Egger’s test for publication bias was not significant (P = 0.17), indicating no evidence of publication bias within the included studies. A funnel plot was also created to illustrate the absence of publication bias [Figure 3].

Figure 3.

Funnel plot for assessing publication bias for prevalence of pulmonary TB among tribal populations

To obtain a more precise estimate of the prevalence of TB in India, a thorough subgroup analysis was conducted to evaluate the differences in prevalence estimates based on gender, age group, location, methodology, and year of study. The pooled prevalence of TB was significantly higher among males (1865.6 [95% CI 841.8–3278.3]) than among females (579.4 [95% CI 314.4–922.7]; P = 0.02) [Figure 4]. Within the age group analysis, the prevalence increased with age, with the highest pooled prevalence observed among individuals aged > 55 years. The age groups 15-34 years and 35-54 years had pooled prevalence of 758.8 [95% CI 317.1-1386.1] and 1923.8 [95% CI 786.0-3544.5], respectively [Figure 5]. Regarding temporal trends, studies conducted between 2000 and 2010 exhibited a pooled prevalence of 589.2 (95% CI: 297.0–977.0), whereas studies conducted during 2011-2022 showed a higher pooled prevalence of 1135.4 (95% CI: 545.3-1934.4) [Figure 6]. The subgroup analysis based on location revealed a higher prevalence of TB in Madhya Pradesh (1135.6 [95% CI: 653.3-1747.2]) compared to other parts of India (605.6 [95% CI: 413.5-833.3]) [Supplementary 3 ^{(182.1KB, tif)} ]. Furthermore, studies employing both sputum culture and sputum AFB as diagnostic methods showed a higher pooled prevalence (1039.8 [95% CI: 532.4-1711.2]) than studies relying solely on sputum AFB (548.0 [95% CI: 107.2-1316.5]) [Supplementary 4 ^{(183.4KB, tif)} ].

Figure 4.

Forest plot of meta-analysis of the TB prevalence among tribal population in India and its gender wise distribution

Figure 5.

Forest plot of meta-analysis of the TB prevalence among tribal populations in India and its age-group wise distribution

Figure 6.

Forest plot of meta-analysis of the TB prevalence among tribal populations in India and its decadal trend in India

DISCUSSION

This systematic review aimed to summarize the available evidence on TB. TB is a significant public health challenge in India. It is crucial to know the burden of TB among tribal communities.[22] Evidence indicates that the prevalence of pulmonary TB is higher among tribal populations, 703 per 100,000 compared to the national average (316 per 100,000).[23,24] India has the highest burden of global TB.[25] At the same time, India is committed to ending the TB epidemic by 2025, five years ahead of the sustainable development goals (SDG) target timeline.[26] The last published meta-analysis with the same objective generated a pooled estimate of 703 per 100,000 population (95% CI 386-1011). This review included seven studies conducted in India, till the year 2010.[27] It is important to note that TB prevalence is significantly higher among men than women in low- and middle-income countries, which is attributed to factors such as undiagnosed and untreated HIV co-infection, missed opportunities for TB screening within HIV care, and notification bias among males.[28] This finding is not restricted to the tribal population but to the general population.

The tribal population has an alarmingly greater prevalence of TB than the general population, highlighting the need for targeted efforts to actively identify cases and implement comprehensive interventions within a specific group. Such measures would facilitate the early detection and treatment of TB while effectively reducing its transmission. The various barriers identified to be responsible for this are as follows: public health services not being client-centric because of variations in the timings, cultural beliefs, weak community participation and other organizations, limitations of non-tribal health staff in working with the tribal population, low incentives for accredited social health activist (ASHA) leading to poor commitment, non-availability of medicines in health facilities, lack of qualified doctors, time delay in investigation results, inadequate contact screening and chemoprophylaxis, non-availability of service providers due to vacant posts, and lack of residential facilities. Apart from these, there are socio-cultural factors, such as belief in faith healing, poor nutrition and housing, poor knowledge about government schemes, addiction, difficult terrains, and lack of transportation facilities.[29]

The Ministry of Health and Family Welfare and the Ministry of Tribal Affairs have signed a Joint Action Plan for Elimination of TB. Following this unique partnership, the Tribal TB Initiative was launched in March 2021 to achieve India’s vision of ‘Ending TB with a priority focus on TB hotspots in tribal areas’. A campaign called “Aashwasan” targeting COVID-19 awareness and Tuberculosis Active Case finding was initiated in January 2022. The National Technical Support Unit for Tribal TB was established by the Piramal Swasthya Management Research Institute with support from the United States Agency for International Development, India. This works in collaboration with the Central TB Division and the Ministry of Tribal Affairs.[30,31,32] High TB transmission settings, such as tribal areas, have been prioritized for TB preventive therapy. Apart from Nikshay Poshan Yojana, honorarium for treatment supporters, notification and treatment outcome incentives for private sector providers, and transport services for TB patients in notified tribal areas have begun to deal with the increased burden. Furthermore, under the Tribal Support Scheme, a one-time financial incentive of Rs. 750 is provided to the notified TB patients residing in tribal areas.[30]

The quality of studies included in this systematic review was assessed using the JBI checklist for prevalence studies. After careful observation, it was noted that the included studies scored high (i.e. of good quality). While the lowest score received by two studies was five, four studies scored nine on the scale.

A high level of heterogeneity was noted in our study (I² = 99%). This is explained by the variability in study designs, outcome measurement tools, timeframes, and study populations. The random effects model was used for the meta-analysis. Subgroup analyses were performed to address the heterogeneity across the studies.[33]

We performed a subgroup analysis to check for time trends. Studies conducted between 2000 and 2010 had a lower pooled prevalence than those conducted between 2011 and 2023. Studies in Madhya Pradesh have revealed a higher pooled prevalence than studies from the rest of India. Madhya Pradesh consists of 14.7% tribal population. Of these, three tribes are identified as vulnerable tribal groups. Factors such as malnutrition, poverty, overcrowding, illiteracy, geographical isolation, unique cultural practices, addiction, preference for faith healers, and inequitable access to healthcare contribute to the increased TB burden. There has been improvement in case notification, from 2018 onwards owing to improved supervision and monitoring.[34]

These studies used sputum microscopy, sputum microscopy, and sputum culture for diagnosis. In four studies, diagnoses were confirmed by sputum microscopy examination. These studies had a lower pooled prevalence than that calculated from studies that utilized both methods. The diagnostic accuracy of sputum AFB examination is 92.85%, sensitivity 63.63%, when compared to bacilli culture.[35]

Publication bias occurs when the outcome of a study influences the likelihood of its publication, leading to an overrepresentation of studies with statistically significant results. This bias can affect the overall conclusions drawn from a meta-analysis. Our study has no publication bias since the funnel plot was observed to be symmetrical.[36] The Eggers test revealed no small study effect.[37] Sub-group analyses were performed to determine the differences in pooled prevalence among different strata. However, our study is not beyond limitations. We could not include grey literature in our study. This study also has high heterogeneity, limiting generalizability. Cautious interpretation of results should be made.

Our study underlines the public health menace caused by the heavy burden of tribal TB. The problem is multifactorial and needs to be explored via nationwide studies with more representative population groups. Most of the studies are conducted in the tribal population of Madhya Pradesh, whereas a huge proportion of the population belongs to the tribal category in several other states of India, like the North-Eastern states.[38] More researches are strongly needed to formulate inclusive health policies addressing the health problems in this vulnerable population. This may pose a different and more difficult challenge than the rest of the nation’s population, but the purpose of Universal Health Coverage is defeated without this.

CONCLUSION

The tribal population is a high-transmission population with respect to TB. Our review highlights the fact that the prevalence of TB is higher in tribal populations when compared to the national prevalence. The research reports available for the prevalence of TB among tribal populations are restricted to a few tribes only. Further research should be conducted to estimate the prevalence among other tribes all over the country. The various strategies under the Tribal TB initiative would benefit from such studies, evaluating the disease burden among vulnerable populations. This would definitely help in achieving the nation’s commitment towards the elimination of the socio-clinical disease.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

SUPPLEMENTARY DATA

Supplementary 2

Forest plot of meta-analysis of the TB prevalence among tribal population in India (Excluding 2 studies).

Supplementary 3

Forest plot of meta-analysis of the TB prevalence among tribal population in India and its state wise distribution

Supplementary 4

Forest plot of meta-analysis of the TB prevalence among tribal population in India and its method wise (1= AFB, 2 = AFB + Culture) distribution