Human movement, cooperation and the effectiveness of coordinated vector control strategies

Abstract

Vector-borne disease transmission is often typified by highly focal transmission and influenced by movement of hosts and vectors across different scales. The ecological and environmental conditions (including those created by humans through vector control programmes) that result in metapopulation dynamics remain poorly understood. The development of control strategies that would most effectively limit outbreaks given such dynamics is particularly urgent given the recent epidemics of dengue, chikungunya and Zika viruses. We developed a stochastic, spatial model of vector-borne disease transmission, allowing for movement of hosts between patches. Our model is applicable to arbovirus transmission by Aedes aegypti in urban settings and was parametrized to capture Zika virus transmission in particular. Using simulations, we investigated the extent to which two aspects of vector control strategies are affected by human commuting patterns: the extent of coordination and cooperation between neighbouring communities. We find that transmission intensity is highest at intermediate levels of host movement. The extent to which coordination of control activities among neighbouring patches decreases the prevalence of infection is affected by both how frequently humans commute and the proportion of neighbouring patches that commits to vector surveillance and control activities. At high levels of host movement, patches that do not contribute to vector control may act as sources of infection in the landscape, yet have comparable levels of prevalence as patches that do cooperate. This result suggests that real cooperation among neighbours will be critical to the development of effective pro-active strategies for vector-borne disease control in today's commuter-linked communities.

(Meta)population dynamics determine effective spatial distributions of mosquito‐borne disease control

“…Stone et al. () employ a similar model on a larger 10 × 10 landscape. Once we have investigated the dynamics occurring in this smaller landscape, we plan to scale up our simulations as well.…”

“…We chose this configuration because it is the minimal size that produces different cell types based on location, in addition to simple edge and interior patches. Stone et al (2017) employ a similar model on a larger 10 9 10 landscape. Once we have investigated the dynamics occurring in this smaller landscape, we plan to scale up our simulations as well.…”

“…, Stone et al. ) or in infected mosquitoes that often get transported via human travel networks (Eritja et al. ).…”

Coordination among neighbors improves the efficacy of Zika control despite economic costs

“…Mosquitoes disperse among adjacent patches with equal probability (Table S1). We assume humans are mobile enough at the spatial scale of the model that a mosquito in any patch can bite any human (but see [27] for analyses in which this assumption is relaxed). The time scale of the model is such that we assume a fixed human population (no human birth or death).…”

“…In practice, though, control is often implemented at the local level by individual towns or households [24,25], without consideration of the best timing or spatial distribution for landscape-level control [26]. Given these limitations, coordination of vector control among patches has the potential to greatly improve the efficiency of disease mitigation during an outbreak [27].…”