Downgrading disease transmission risk estimates using terminal importations

by Spencer J. Fox, Steven E. Bellan, T. Alex Perkins, Michael A. Johansson, Lauren Ancel Meyers As emerging and re-emerging infectious arboviruses like dengue, chikungunya, and Zika threaten new populations worldwide, officials scramble to assess local severity and transmissibility, with little to no epidemiological history to draw upon. Indirect estimates of risk from vector habitat suitabi lity maps are prone to great uncertainty, while direct estimates from epidemiological data are only possible after cases accumulate and, given environmental constraints on arbovirus transmission, cannot be widely generalized beyond the focal region. Combining these complementary methods, we use dise ase importation and transmission data to improve the accuracy and precision ofa priori ecological risk estimates. We demonstrate this approach by estimating the spatiotemporal risks of Zika virus transmission throughout Texas, a high-risk region in the southern United States. Our estimates are, on average, 80% lower than published ecological estimates —with only six of 254 Texas counties deemed capable of sustaining a Zika epidemic—and they are consistent with the number of autochthonous cases detected in 2017. Importantly our method provides a framework for model comparison, as our mechanistic understanding of arbovirus transmission continue s to improve. Real-time updating of prior risk estimates as importations and outbreaks arise can thereby provide critical, early insight into local ...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research