Abstract
Ecologists are increasingly involved in the pandemic prediction process. In the course of the 2015-2016 outbreak of Zika virus, several ecological models were developed to forecast the potential global distribution of the disease. Conflicting results produced by alternative methods are unresolved, hindering the development of appropriate public health forecasts. We compare ecological niche models and experimentally-driven mechanistic forecasts for Zika transmission in the continental United States, a region of high model conflict. Based on plausible epidemiological parameters, we use stochastic county-level simulations to demonstrate the epidemiological consequences of conflict among ecological models. We also propose a basic consensus method that could resolve conflicting models of potential outbreak geography and seasonality, but we note that it fails to produce substantially more realistic outbreak trajectories. Our results illustrate the unacceptable margin of uncertainty contained within these predictions, which could misrepresent the risk faced by millions of people in the United States within a single year. In the short term, ecologists face the task of developing better post hoc consensus that accurately forecasts spatial patterns of Zika virus outbreaks. Ultimately, methods are needed that bridge the gap between ecological and epidemiological approaches to predicting transmission and realistically capture both outbreak size and geography.
Footnotes
↵* cjcarlson@berkeley.edu