Department of Epidemiology of Microbial Diseases, Yale University, New Haven, Connecticut, United States of America.
Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan, United States of America.
PLoS Comput Biol. 2021 Feb 8;17(2):e1008713. doi: 10.1371/journal.pcbi.1008713. eCollection 2021 Feb.
There is an emerging consensus that achieving global tuberculosis control targets will require more proactive case finding approaches than are currently used in high-incidence settings. Household contact tracing (HHCT), for which households of newly diagnosed cases are actively screened for additional infected individuals is a potentially efficient approach to finding new cases of tuberculosis, however randomized trials assessing the population-level effects of such interventions in settings with sustained community transmission have shown mixed results. One potential explanation for this is that household transmission is responsible for a variable proportion of population-level tuberculosis burden between settings. For example, transmission is more likely to occur in households in settings with a lower tuberculosis burden and where individuals mix preferentially in local areas, compared with settings with higher disease burden and more dispersed mixing. To better understand the relationship between endemic incidence levels, social mixing, and the impact of HHCT, we developed a spatially explicit model of coupled household and community transmission. We found that the impact of HHCT was robust across settings of varied incidence and community contact patterns. In contrast, we found that the effects of community contact tracing interventions were sensitive to community contact patterns. Our results suggest that the protective benefits of HHCT are robust and the benefits of this intervention are likely to be maintained across epidemiological settings.
目前有一种共识，即要实现全球结核病控制目标，就需要采取比目前在高发病率地区使用的更积极的病例发现方法。家庭接触者追踪（HHCT）是一种潜在有效的方法，可以发现新的结核病病例，即主动对新诊断病例的家庭进行额外的感染筛查，但评估此类干预措施在持续社区传播环境中的人群水平效果的随机试验结果喜忧参半。造成这种情况的一个可能原因是，家庭传播在不同环境中造成了人群结核病负担的不同比例。例如，在结核病负担较低且个体在当地更倾向于混合的环境中，与疾病负担较高且混合更为分散的环境相比，家庭传播更有可能发生。为了更好地理解地方性发病率水平、社会混合以及 HHCT 的影响之间的关系，我们开发了一个家庭和社区传播的空间明确模型。我们发现，HHCT 的影响在不同发病率和社区接触模式的环境中是稳健的。相比之下，我们发现社区接触追踪干预的效果对社区接触模式敏感。我们的研究结果表明，HHCT 的保护效益是稳健的，这种干预措施的效益可能在不同的流行病学环境中得到维持。
