Modeling plant disease spread via high-resolution human mobility networks

TL;DR

This study develops a high-resolution human mobility network model to accurately simulate and analyze the spread of plant disease, specifically kiwifruit vine disease, highlighting the importance of human movement patterns in epidemic dynamics.

Contribution

It introduces a novel integration of detailed human mobility data with a plant disease spread model, providing a new framework for predicting and controlling agricultural epidemics.

Findings

Model accurately reproduces observed disease spread in New Zealand.

Local dispersal dominates, but long-range links are crucial for nationwide outbreaks.

Enhanced surveillance and timing of interventions significantly impact outbreak severity.

Abstract

Human mobility plays a crucial role in the spread of human diseases, but is rarely quantified in plant disease epidemics. To address this gap, we integrate a unique, high-resolution network of human movements in New Zealand with a metapopulation model to mechanistically simulate pathogen transmission. We calibrate the model on the nationwide 2010 kiwifruit vine disease (Psa-V) outbreak, and show that it accurately reproduces the observed spatiotemporal spread, confirming that the human mobility network is a strong foundation for modeling transmission dynamics. By analyzing spatial infection trends, we find that most dispersal occurs locally, as often illustrated in the plant-outbreak literature. However, sporadic long-range connections are necessary to model a nationwide outbreak. Using the model as an in-silico laboratory, we demonstrate that enhanced surveillance accelerates detection and that outbreak severity is highly sensitive to the timing and location of initial disease importation. We observe a potential causal link between seasonal labor patterns and epidemic risk in high-traffic seasons. This study provides a robust, data-driven framework for modeling and predicting the spatiotemporal spread of agricultural pathogens. It underscores the importance of leveraging human mobility networks to design timely interventions and surveillance systems, protecting global food security.