Mining and risk of tuberculosis in sub-Saharan Africa

Abstract

Objectives: We estimated the relationship between mining and tuberculosis (TB) among countries in sub-Saharan Africa.

Methods: We used multivariate regression to estimate the contribution of mining activity to TB incidence, prevalence, and mortality, as well as rates of TB among people living with HIV, with control for economic, health system, and population confounders.

Results: Mining production was associated with higher population TB incidence rates (adjusted b = 0.093; 95% confidence interval [CI] = 0.067, 0.120; with an increase of mining production of 1 SD corresponding to about 33% higher TB incidence or 760,000 more incident cases), after adjustment for economic and population controls. Similar results were observed for TB prevalence and mortality, as well as with alternative measures of mining activity. Independent of HIV, there were significant associations between mining production and TB incidence in countries with high HIV prevalence (≥ 4% antenatal HIV prevalence; HIV-adjusted B = 0.066; 95% CI = 0.050, 0.082) and between log gold mining production and TB incidence in all studied countries (HIV-adjusted B = 0.053; 95% CI = 0.032, 0.073).

Conclusions: Mining is a significant determinant of countrywide variation in TB among sub-Saharan African nations. Comprehensive TB control strategies should explicitly address the role of mining activity and environments in the epidemic.

FIGURE 1

Trends in tuberculosis incidence among 46 African countries, stratified by antenatal HIV prevalence: 1990–2006. Note. African countries for which comparative data are presented are as follows: those whose average antenatal HIV prevalence rates between 1990 and 2006 were 4% or higher (Botswana, Burkina Faso, Burundi, Central African Republic, Chad, Democratic Republic of Congo, Republic of Congo, Cote d'Ivoire, Djibouti, Eritrea, Ethiopia, Kenya, Lesotho, Liberia, Madagascar, Malawi, Mali, Mauritania, Mozambique, Namibia, Niger, Rwanda, Sao Tome and Principe, Seychelles, Somalia, South Africa, Swaziland, Uganda, Zimbabwe), and those whose average antenatal HIV prevalence rates between 1990 and 2006 were below 4% (Angola, Benin, Cameroon, Cape Verde, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Mauritius, Nigeria, Senegal, Sierra Leone, Tanzania, Togo, Zambia). Source. Data are from the World Health Organization Global Tuberculosis Database, 2009 edition.² HIV prevalence data are based on Joint United Nations Programme on HIV/AIDS Estimation and Projections Package³ logistic estimates of antenatal HIV prevalence rates.