Silicosis and silicotuberculosis amongst small scale gemstone miners in Northern Tanzania

在全球范围内，约有4600万人在“手工小型矿山”（ASM）工作，远远超过大型矿山的700万人。asm仅位于资源贫乏的国家，由当地所有，不受监管，并使用人工开采方法-但总共生产了全球高达四分之一的矿物和贵金属。虽然手工采矿可能是摆脱贫困的一条途径，但这种工作的风险很高，而且几乎完全无法衡量。最近对ASM研究的研究主题进行了审查，结论是需要进行更多的研究，特别是对传染病（如结核病）和呼吸道疾病的研究。矽肺病是一种无法治愈的肺部疾病，是由在开采坚硬岩石等活动中吸入结晶二氧化硅引起的。它通常发展缓慢，但当二氧化硅含量非常高时，可能会更快地发病，早期呼吸衰竭和死亡。重要的是，矽肺病使患肺结核（TB）的风险增加了约四倍，矿工除了矽肺病之外，还经常感染这种疾病。坦桑石是一种仅在坦桑尼亚北部Mererani发现的宝石，由大约10,000名工人在大约100个矿山中使用ASM方法在深井中开采。他们对二氧化硅的暴露似乎非常高，并且有暗示性证据表明，在就业不到5年的年轻矿工中，侵略性矽肺病的发病率非常高。同样，他们的结核病发病率也很高，当地的非采矿社区也是如此。人们担心，该地区控制结核病的努力受到矿井内以及矿工与其当地接触者之间疾病传播的阻碍。我的目标是测量随着时间的推移，坦桑石矿工矽肺病和结核病的发展和进展，并确定这些对他们的健康和谋生能力有多大影响。此外，我将研究结核病从矿工传播到当地社区是否普遍。为此，我提出了两项研究。首先，我将从10-16个矿场中招募并跟踪410名矿工。在他们身上，我将测量他们的肺功能和症状，并在研究开始时进行结核病检查和胸部x光检查（以检测矽肺病），然后在18个月后再次进行检查。在第二项研究中，我将使用“全基因组测序”（WGS）来识别患有结核病的矿工的特定结核菌株；我将对通过当地社区筛查项目发现的结核病患者使用同样的技术。WGS是一种可以读取生物体整个遗传密码的技术。它将使我能够确定人群中存在哪些结核菌株，同时检查对治疗的耐药性，并且至关重要的是，绘制个体之间的传播图谱。这项工作将与坦桑尼亚国立结核病医院Kibong'oto传染病医院的传染病小组合作完成，利用其正在进行的结核病筛查方案以及与当地ASM社区的密切关系。为了协助研究管理和增强影响，我将召集一个由利益攸关方组成的研究咨询委员会，包括我们在国家结核病和麻风病规划的合作者、专家学者以及当地矿山和以前接受过结核病治疗的人的组织的代表。这项新颖的工作涉及职业病和传染病之间的交叉，并应产生对预防这两种疾病都具有重要意义的发现——在一个日益重要的全球部门。

Worldwide, some 46m people work in 'artisanal, small scale mines' (ASM), a number far larger than the 7m employed in large scale mining. ASMs are located exclusively in resource-poor countries, are locally owned, unregulated and use manual methods of extraction - but collectively produce up to a quarter of global minerals and precious metals. While artisanal mining may be a route out of poverty, the risks of such work are high, yet almost entirely unmeasured. A recent review of research topics in studies of ASM, concluded that more research was needed, particularly of infectious (such as tuberculosis) and respiratory diseases.Silicosis is an incurable lung disease caused by the inhalation of crystalline silica in activities such as hard rock mining. It generally develops slowly, but when levels of silica are very high there may be a far more rapid onset with early respiratory failure and death. Importantly, silicosis increases the risk of tuberculosis (TB) by about four-fold and miners often contract the disease in addition to silicosis. Tanzanite is a gemstone exclusively found in Mererani, northern Tanzania, and mined in deep shafts using ASM methods by around 10,000 workers, across about 100 mines. Their exposures to silica appear to be very high, and there is suggestive evidence of very high rates of aggressive silicosis in young miners with fewer than 5 years of employment. Similarly, their rates of TB are high, as are those in the local non-mining community. There is concern that efforts to control TB in the area are hampered by transmission of the disease within mines, and between miners and their local contacts.I aim to measure, across time, the development and progression of silicosis and TB in tanzanite miners and determine how much these have an impact on their health and their ability to earn a living. In addition, I will examine whether the spread of TB from miners to the local community is common.To do this I propose two studies. In the first, I will recruit and follow a group of 410 miners from a selection of 10-16 mines. In them, I will make measurements of their lung function and symptoms, and perform TB tests and chest x-rays (to detect silicosis) at the beginning of the study and then again after 18 months. In a second study, I will use 'whole genome sequencing' (WGS) to identify particular strains of TB in miners with the diseases; I will use the same technique in individuals discovered to have TB through a local community screening program. WGS is technique that that allows for entire genetic codes of an organism to be read. It will allow me to identify which strains of TB are present in the population while checking for resistance to treatments, and, crucially, to map transmission between individuals.This work will be done in collaboration with the infectious disease team at the Kibong'oto Infectious Diseases Hospital, the National TB hospital of Tanzania, taking advantage of their ongoing TB screening programme and close relationships with the local ASM community. To assist with study management and to enhance impact, I will convene a study Advisory Board of stakeholders including our collaborators at the National TB and Leprosy program, expert academics, and representatives from the local mines and from organisations for persons previously treated for TB.This novel work concerns the intersection between occupational and infectious diseases and should produce findings that will be of importance in the prevention of both - in a sector that is of growing, global importance.