This is a cross-sectional study with an analytical purpose.

Lualaba province was selected by the National Tuberculosis Control Programme on the basis of a combination of criteria, including TB incidence and safety in this specific population.

This province includes a Provincial Coordination for the Fight against Tuberculosis (CPLT), which operates with 13 health zones in accordance with its geographical coverage, including the ZS of Manika, Kanzenze, Dilala, Lualaba and Fungurume, which include the 15 study sites. The table shows the distribution of artisanal mining quarries (AMCs) in these five SAs.

Data collection was preceded by training of national supervisors and then of interviewers at the provincial level.

The survey used a quantitative approach and targeted two groups of respondents:

There are very few studies on risk factors for TB among minors in the DRC. However, a recent study in Tanzania showed that about 7% of miners had tuberculosis [19] . Thus, to estimate the sample size, detect the proportion of the study population, determine the prevalence of tuberculosis, and identify the risk factors related to TB in this population in the DRC, we applied the following formula:

$n=k{t}^2\frac{P\left(1-P\right)}{e^2}$

To calculate the sample size of minors with tuberculosis, it is necessary to take into account the following factors: the desired level of confidence in the survey results (S), the acceptable margin of error for the survey results (e), the effect of the sampling design (k) and the estimated initial levels of the indicators to be measured (p).

In concrete terms, n = sample size; S = 95%, then t = 1.96 “study of acceptable accuracy”; p is the proportion of miners suffering from tuberculosis on (0.07).

Then, n = 2 × 1.96² × 0.07 (1 − 0.07)/0.04² = 319 per ZS, which we increase to 320 per ZS. In consideration of the non-response rate and for fear of falling to a minimum size, we added 15% of non-respondents. The sample size was increased to 367, which was rounded to 370 for each of the five target ZS of the study. The minimum size was 1600 people which was divided between the respondents and the 15 study sites.

Choice of Statistical Units of Study

1) Choice of primary units (1st degree):

2) Choice of artisanal miners (2nd degree):

Interviews were conducted with miners and members of the peri-mining community selected from the artisanal mines of Lualaba.

The inclusion criteria for study participants were: for miners, those who have at least one year’s service as a miner, be involved in the mine’s activities on a daily basis, consent to the study, and be able to participate. Whereas for the peri-mining population, the study included those who reside in the vicinity of one or more artisanal mines (at most 10 km from the mine) and have lived for at least one year in the vicinity. The exclusion criteria were if the respondent was unable or unwilling to give consent and adult members of the peri-mining community who have been living near one or more artisanal mines for less than one year and have not given consent to participate in the study.

The selected artisanal mines and peri-mining community members were contacted by the community relays (RECO). The latter helped the interviewers to find the addresses of households to set the date of the interviews. Interviews were carried out using the questionnaire, and sputum collection was conducted from the selected individuals.

Sputum samples were obtained either spontaneously or induced using a spittoon by the community outreach workers wearing respiratory protection masks to avoid inhaling bacilli [20] . They were then sent to the 4 biological analysis laboratories targeted by the study at the provincial level: Kizito, HPK, LPR, and DIPETA/Fungurume. GeneXperts was used to confirm cases of tuberculosis and rifampin resistance.

The data was encoded in the field on tablets using the Surveycto mobile app. This contained the input mask set up with XLSForm on the basis of the data collection sheet (made with the Sphinx® software). The encoded forms were submitted to the surveyCTO server by the supervisors.

Subsequently, the database was downloaded and submitted for analysis (after quality control and data cleaning). Internal quality control was carried out by the national supervisors and the biostatistician after the submission of the completed questionnaires. Data cleaning allowed for data verification, control, and correction. The audit included identifying inconsistencies, missing data, and data entry errors.

The quantitative data were analyzed with the R® 4.2.4 software, and the results were presented in the form of tables synthesized according to the numbers, frequencies, and associated proportions or in the form of illustrations through maps and graphs. Categorical variables were summarized by their relative frequencies (and 95% confidence intervals), while numerical variables were summarized by appropriate measures of central tendency. Median comparisons were performed using the Wilcoxon test, while proportions were compared using the exact Fisher test. In addition, for comparisons and associations between the dependent variable “respondent status” and the other variables, the Pearson Chi² test or the exact Fisher test was used.

In addition, a multivariate logistic regression was performed with the variable “respondent status” having two modalities (miner and member of the peri-mining community) and the explanatory variables. A general linear regression model (GLM) analysis with a significance level (p) of 5% was performed, and the odds ratios were calculated using their confidence interval. However, several models have been made, and we have retained those with the smallest Akaike indices.

The study protocol was submitted to the Ethics Committee for approval prior to the start of this research activity. After approval, an information letter was sent to the CPLT of the province of Lualaba (target of the study) to inform them of the study, including its objectives and methods.

In accordance with the principle of informed consent, the study on the prevalence and risk factors of tuberculosis will be based on an informed consent form in the local language and French, to ask each respondent to give their consent for the collection and processing of their personal data (after being fully informed of the nature of the study, of the persons involved in it, of the way in which the data is processed, stored and used). Interviewers explained to respondents that they are free to decline the interview, to withdraw from the interview at any time, or to refuse to answer a particular question or set of questions. Interviewers ensured that the respondent had given informed consent based on the informed consent form before starting the interview.

Confidentiality refers to the right of access to data provided by study participants. The only people allowed to see the list containing the contact and codes of all respondents and the informed consent forms were the interviewers who collected the data and the supervisors. Those responsible for verifying and analyzing the data did not have access to the list that contained the respondents’ personal contact information.

In order to ensure the confidentiality of the data, agreements were signed by the research team, investigators, and supervisors.

The interviewers provided participants with information about the care services available in the province. The objective was to inform respondents about the services available to meet their health needs. As a result, all respondents who tested positive for GeneXpert were put on treatment.

The direct benefits of the study include the development of an action plan to support the implementation of programs to improve access to TB diagnosis and management in artisanal mines in DRC. Measuring TB prevalence and identifying TB risk factors among miners and peri-mining communities can contribute to improved screening, expanding universal coverage of tuberculosis preventive treatment (TPT), drug-resistant tuberculosis treatment (DRTB) and drug-susceptible TB (TBPSM), and improving community access to TB services.

Participants were asked about their personal information, sensitive behaviors, and exposure to response activities, and such information was probably subject to a social desirability bias and a memorization bias. In addition, participants who agreed to enroll, consent, and participate in the study may be more likely to comply with the terms of enrollment, program retention, and treatment adherence than those who declined to participate.

The data collection was conducted in October and November 2023 in the selected sites located in Lualaba province.

The study covered 15 mining sites in Lualaba province. These artisanal mining sites represented the majority (86%) of copper and cobalt. A total of 1778 subjects were recruited for the study, with equal representation of both groups of respondents: 889 peri-mining communities and 889 artisanal miners. In terms of gender composition, 1275 (72%) were male and 503 (28%) were female.

As shown in Table 1 , the median age for the two groups of respondents was similar: 31 (QIS 24.0 - 42.0) years for the peri-mining population (PMN) and 32 (QIS 25.0 - 40.0) years for miners (MN). The most representative age group was 20 - 40 years old for both groups. The two groups (MNP and MN) differ in a number of characteristics, including the gender distribution (37% of women for MNs versus 20% for MNs). The majority, 468 (80.0%) of respondents, had attended an elementary or secondary level education, whereas 17% had never been to school and only 2.5% had a university level degree. Among the peri-mining population, 422 (47.0%) had primary education, while for miners, the figure was 457 (51.0%).

¹n: Median (IQR). ²Pearson’s Chi-squared test; Wilcoxon rank sum test; Fischer’s exact test.

As shown in Table 2 , a total of 73 individuals were found to be positive by GeneXpert testing using sputum samples, which gives rise to a combined prevalence of tuberculosis for the two studied subpopulations of 4,1%. With further disaggregation by the type of respondent, the prevalence was 5.2% for MNs compared to 3.0% for the peri-mining community. The difference was statistically significant, with a P-value of 0.023.

¹n: Median (IQR). ²Pearson’s Chi-squared test; Wilcoxon rank sum test; Fischer’s exact test.

As shown in Figure 1 , GeneXpert’s positivity rate by sex showed that 22 of the females and 52 of the male participants were positive for the test.

Support the NTP and the government in the implementation of the recommendations from this study in order to achieve the goal of eliminating TB in the DRC by 2030.