Epidemiological Implications of Host Biodiversity and Vector Biology: Key Insights from Simple Models


Dobson A & Auld S (2016) Epidemiological Implications of Host Biodiversity and Vector Biology: Key Insights from Simple Models. American Naturalist, 187 (4), pp. 405-422.;

Models used to investigate the relationship between biodiversity change and vector-borne disease risk often do not explicitly include the vector; they instead rely on a frequency-dependent transmission function to represent vector dynamics. However, differences between classes of vector (e.g., ticks and insects) can cause discrepancies in epidemiological responses to environmental change. Using a pair of disease models (mosquito- and tick-borne), we simulated substitutive and additive biodiversity change (where noncompetent hosts replaced or were added to competent hosts, respectively), while considering different relationships between vector and host densities. We found important differences between classes of vector, including an increased likelihood of amplified disease risk under additive biodiversity change in mosquito models, driven by higher vector biting rates. We also draw attention to more general phenomena, such as a negative relationship between initial infection prevalence in vectors and likelihood of dilution, and the potential for a rise in density of infected vectors to occur simultaneously with a decline in proportion of infected hosts. This has important implications; the density of infected vectors is the most valid metric for primarily zoonotic infections, while the proportion of infected hosts is more relevant for infections where humans are a primary host.

vector-borne disease; tick-borne disease; biodiversity; dilution effect; disease risk

American Naturalist: Volume 187, Issue 4

FundersNatural Environment Research Council
Publication date30/04/2016
Publication date online29/02/2016
Date accepted by journal19/11/2015
PublisherUniversity of Chicago Press
Publisher URL