Host Heterogeneity in Susceptibility and Disease Dynamics: Tests of a Mathematical Model
- 1 December 1997
- journal article
- research article
- Published by University of Chicago Press in The American Naturalist
- Vol. 150 (6) , 685-707
- https://doi.org/10.1086/286089
Abstract
Most mathematical models of disease assume that transmission is linearly dependent on the densities of host and pathogen. Recent data for animal diseases, however, have cast doubt on this assumption, without assessing the usefulness of alternative models. In this article, we use a combination of laboratory dose‐response experiments, field transmission experiments, and observations of naturally occurring populations to show that virus transmission in gypsy moths is a nonlinear function of virus density, apparently because of heterogeneity among individual gypsy moth larvae in their susceptibility to the virus. Dose‐response experiments showed that larvae from a laboratory colony of gypsy moths are substantially less heterogeneous in their susceptibility to the virus than are larvae from feral populations, and field experiments showed that there is a more strongly nonlinear relationship between transmission and virus density for feral larvae than for lab larvae. This nonlinearity in transmission changes the dynamics of the virus in natural populations so that a model incorporating host heterogeneity in susceptibility to the virus gives a much better fit to data on virus dynamics from large‐scale field plots than does a classical model that ignores host heterogeneity. Our results suggest that heterogeneity among individuals has important effects on the dynamics of disease in insects at several spatial and temporal scales and that heterogeneity in susceptibility may be of general importance in the ecology of disease.Keywords
This publication has 47 references indexed in Scilit:
- Epidemic Models: Their Structure and Relation to Data.Published by JSTOR ,1996
- Host Dispersal and the Spatial Spread of Insect PathogensEcology, 1995
- Transmission Dynamics of a Virus in a Stage‐Structured Insect PopulationEcology, 1995
- Infectious diseases of wildlife, in theory and in practiceTrends in Ecology & Evolution, 1993
- Aggregation and stability in parasite—host modelsParasitology, 1992
- Non-linear transmission rates and the dynamics of infectious diseaseJournal of Theoretical Biology, 1991
- Analysing dose‐mortality data when doses are subject to errorAnnals of Applied Biology, 1991
- A Preliminary Study of the Transmission Dynamics of the Human Immunodeficiency Virus (HIV), the Causative Agent of AIDSMathematical Medicine and Biology: A Journal of the IMA, 1986
- Population biology of infectious diseases: Part INature, 1979
- Regulation and Stability of Host-Parasite Population Interactions: I. Regulatory ProcessesJournal of Animal Ecology, 1978