Population-Level Impact of Same-Day Microscopy and Xpert MTB/RIF for Tuberculosis Diagnosis in Africa

ObjectiveTo compare the population-level impact of two World Health Organization-endorsed strategies for improving the diagnosis of tuberculosis (TB): same-day microscopy and Xpert MTB/RIF (Cepheid, USA).MethodsWe created a compartmental transmission model of TB in a representative African community, fit to the regional incidence and mortality of TB and HIV. We compared the population-level reduction in TB burden over ten years achievable with implementation over two years of same-day microscopy, Xpert MTB/RIF testing, and the combination of both approaches.FindingsSame-day microscopy averted an estimated 11.0% of TB incidence over ten years (95% uncertainty range, UR: 3.3%–22.5%), and prevented 11.8% of all TB deaths (95% UR: 7.7%–27.1%). Scaling up Xpert MTB/RIF to all centralized laboratories to achieve 75% population coverage had similar impact on incidence (9.3% reduction, 95% UR: 1.9%–21.5%) and greater effect on mortality (23.8% reduction, 95% UR: 8.6%–33.4%). Combining the two strategies (i.e., same-day microscopy plus Xpert MTB/RIF) generated synergistic effects: an 18.7% reduction in incidence (95% UR: 5.6%–39.2%) and 33.1% reduction in TB mortality (95% UR: 18.1%–50.2%). By the end of year ten, combining same-day microscopy and Xpert MTB/RIF could reduce annual TB mortality by 44% relative to the current standard of care.ConclusionScaling up novel diagnostic tests for TB and optimizing existing ones are complementary strategies that, when combined, may have substantial impact on TB epidemics in Africa.研究目的 比较世界卫生组织（World Health Organization, WHO）认可的两种结核病（tuberculosis, TB）诊断优化策略的人群层面干预效果：当日显微镜检测与Xpert MTB/RIF（美国赛沛（Cepheid）公司产品）。研究方法 我们在具有代表性的非洲社区构建了结核病传播分室模型，并拟合该地区结核病与人类免疫缺陷病毒（Human Immunodeficiency Virus, HIV）的区域发病率及死亡率数据，对比了在两年内推行当日显微镜检测、Xpert MTB/RIF检测，以及两种策略联合应用时，十年内可实现的结核病负担人群层面降幅。研究结果 当日显微镜检测在十年间预计可避免11.0%的结核病新发感染（95%不确定区间（uncertainty range, UR）：3.3%~22.5%），并减少11.8%的结核病死亡（95%不确定区间：7.7%~27.1%）。将Xpert MTB/RIF推广至所有集中化实验室以实现75%的人群覆盖时，其对新发感染的干预效果与当日显微镜检测相近（降幅9.3%，95%不确定区间：1.9%~21.5%），但对死亡率的改善效果更为显著（降幅23.8%，95%不确定区间：8.6%~33.4%）。两种策略联合应用可产生协同效应：新发感染降幅达18.7%（95%不确定区间：5.6%~39.2%），结核病死亡率降幅达33.1%（95%不确定区间：18.1%~50.2%）。至第十年末，联合使用当日显微镜检测与Xpert MTB/RIF检测，相较当前标准诊疗方案可使年度结核病死亡率降低44%。研究结论 推广新型结核病诊断检测技术并优化现有检测手段属于互补策略，二者联合应用或可对非洲的结核病流行产生显著干预效果。