Afonso Dimas Martins

Project

Track: 10, Tools to explore risk of emergence of vector-borne diseases in ecosystems

Promotor

Dr. Hans Heesterbeek

Co-promoter(s)

Dr. Quirine ten Bosch

Institute

Utrecht University, Wageningen University

Description PhD project

To accurately study the establishment of a vector-borne disease (VBD) and the possible development of an outbreak, we must understand the species present in that given ecosystem. The dynamics of a VBD will then be affected directly by the species that serve as a host for the vector, their respective ecological and epidemiological interactions, as well as indirectly by predators or competitors of the host species, competition with other vector species and the ecological interaction with non-host species. If we are to quantify emergence capabilities for VBD it is crucial to understand the influence of the ecosystem context and interactions.

Models and practical tools will be developed to quantify the influence of ecosystem characteristics on the emergence of VBD, using Usutu Virus (USUT) and West-Nile Virus (WNV) as case studies. The focus of these eco-epidemiological models will be the quantification of how those ecosystem dynamics and interactions affect R₀. R₀ is the measure to integrate all relevant factors in an assessment of outbreak risk, taking into consideration local conditions and temporal variations and allowing for optimal integration in risk maps at various levels. We will quantify contributions to R₀ of the various host-vector combinations under a set of ecological conditions.

Research questions / objectives

Extend the generic modelling approach to fully incorporate vectors, hosts, non-hosts and their respective ecological interactions. Quantify how the species interactions affect R₀ using compartmental models. Evaluate the sensitivity of the R₀ estimates.

Tags matching with the contents of track 10

Methods

Modelling
- Epidemiological modelling: I will be developing and analyzing eco-epidemiological ODE models that incorporate the viral cycles as well as information from the ecosystem (competition, predation, etc.)
- Ecological modelling: I will be developing and analyzing eco-epidemiological ODE models that incorporate the viral cycles as well as information from the ecosystem (competition, predation, etc.)

Topics

Vector:
- Vector host-preference: The impact of some mosquito behaviors, such as host-preference, on R₀, will be studied

Species

Species:
- Human: Humans will have a small, yet relevant, role in these models, as they act as accidental dead-end hosts for the viruses in study
- Bird: Birds will act as amplifying hosts and most important reservoirs of these VBDs
- Mosquito: Mosquitoes will be the main vector in out model

Virus

Virus:
- West Nile virus: The models developed will have a primary focus on VBDs with enzootic spillover cycles (such as WNV)
- Usutu Virus: The models developed will have a primary focus on VBDs with enzootic spillover cycles (such as USUV)
- Japanese Encephalitis Virus: The models developed will have a primary focus on VBDs with enzootic spillover cycles (such as JEV)
- Sindbis Virus: The models developed will have a primary focus on VBDs with enzootic spillover cycles (such as SINV)