Centre for Health Economics Research and Modelling Infectious Diseases (CHERMID), Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium.
Data Science Institute (DSI), Hasselt University, Hasselt, Belgium.
Sci Rep. 2020 Nov 12;10(1):19645. doi: 10.1038/s41598-020-76746-3.
When estimating important measures such as the herd immunity threshold, and the corresponding efforts required to eliminate measles, it is often assumed that susceptible individuals are uniformly distributed throughout populations. However, unvaccinated individuals may be clustered in a variety of ways, including by geographic location, by age, in schools, or in households. Here, we investigate to which extent different levels of within-household clustering of susceptible individuals may impact the risk and persistence of measles outbreaks. To this end, we apply an individual-based model, Stride, to a population of 600,000 individuals, using data from Flanders, Belgium. We construct a metric to estimate the level of within-household susceptibility clustering in the population. Furthermore, we compare realistic scenarios regarding the distribution of susceptible individuals within households in terms of their impact on epidemiological measures for outbreak risk and persistence. We find that higher levels of within-household clustering of susceptible individuals increase the risk, size and persistence of measles outbreaks. Ignoring within-household clustering thus leads to underestimations of required measles elimination and outbreak mitigation efforts.
在估算群体免疫阈值等重要指标，以及消除麻疹所需的相应努力时，通常假设易感个体在人群中均匀分布。然而，未接种疫苗的个体可能以多种方式聚集，包括地理位置、年龄、学校或家庭。在这里，我们研究了易感个体在家庭内的不同聚集程度在多大程度上可能影响麻疹暴发的风险和持续时间。为此，我们使用来自比利时佛兰德斯的数据，应用基于个体的 Stride 模型来研究 60 万人的人群。我们构建了一个指标来估计人群中家庭内易感性聚集的程度。此外，我们比较了现实情况下家庭内易感个体分布对暴发风险和持续时间的流行病学措施的影响。我们发现，易感个体在家庭内的聚集程度越高，麻疹暴发的风险、规模和持续时间就越大。因此，忽略家庭内的聚类会导致对消除麻疹和减轻暴发所需努力的低估。
