Heterogeneity in tuberculosis transmission and the role of geographic hotspots in propagating epidemics
Heterogeneity in tuberculosis transmission and the role of geographic hotspots in propagating epidemics
复制标题
DOI：
10.1073/pnas.1203517109
复制
发表时间：
2012-06-12
影响因子：
11.1
通讯作者：
Saraceni, Valeria
中科院分区：
文献类型：
--
作者：
Dowdy, David W.;Golub, Jonathan E.;Saraceni, Valeria
高发病率“热点”对人口结核病发病率的重要性仍然知之甚少。结核病发病率在各国之间差异很大，但在较小的地理区域内（例如，由于结核病的传播可能比其他传染病更具有同质性，我们在里约热内卢构建了一个结核病的稳态房室模型，复制了9个流行病学变量（例如，结核病发病率）在其观察值的1%以内。我们估计了结核病传播源自高发热点的比例（占该市人口的6.0%，结核病发病率的16.5%），以及针对热点与一般社区的结核病控制措施的相对影响。如果热点地区每一例活动性结核病病例在一般社区中引起0.5次二次传播，那么生活在热点地区的6.0%的人占全市结核病传播的35.3%。降低TB传输速率（即，与一般社区相比，热点地区的结核病发病率在第5年降低了9.8%，在第50年降低了29.7%--这一效果类似于将社区其余94%的结核病诊断时间减半。结核病热点对全市结核病控制的重要性在很大程度上取决于结核病从热点向一般社区传播的程度。高发病率的热点地区可能在传播结核病流行方面发挥重要作用。在一个占城市人口6%的热点地区实现结核病控制目标，对全市结核病发病率的影响与在其余社区实现相同目标的影响相似。
The importance of high-incidence "hotspots" to population-level tuberculosis (TB) incidence remains poorly understood. TB incidence varies widely across countries, but within smaller geographic areas (e.g., cities), TB transmission may be more homogeneous than other infectious diseases. We constructed a steady-state compartmental model of TB in Rio de Janeiro, replicating nine epidemiological variables (e.g., TB incidence) within 1% of their observed values. We estimated the proportion of TB transmission originating from a high-incidence hotspot (6.0% of the city's population, 16.5% of TB incidence) and the relative impact of TB control measures targeting the hotspot vs. the general community. If each case of active TB in the hotspot caused 0.5 secondary transmissions in the general community for each within-hotspot transmission, the 6.0% of people living in the hotspot accounted for 35.3% of city-wide TB transmission. Reducing the TB transmission rate (i.e., number of secondary infections per infectious case) in the hotspot to that in the general community reduced city-wide TB incidence by 9.8% in year 5, and 29.7% in year 50-an effect similar to halving time to diagnosis for the remaining 94% of the community. The importance of the hotspot to city-wide TB control depended strongly on the extent of TB transmission from the hotspot to the general community. High-incidence hotspots may play an important role in propagating TB epidemics. Achieving TB control targets in a hotspot containing 6% of a city's population can have similar impact on city-wide TB incidence as achieving the same targets throughout the remaining community.