Miners have long been known to experience some of the highest rates of TB in the world. These increased rates are due to silica dust exposure and silicosis, socioeconomic determinants and - among certain populations - co-existent HIV infection. The issue of TB among miners has gained prominence as recent decades have seen a significant increase in the number of small-scale and informal miners. These miners are exposed to higher levels of silica than their large-scale mining counterparts and experience even higher rates of active TB.