Transmission dynamics of a zoonotic pathogen within and between wildlife host species

TLDR

Cowpox virus circulates among bank voles and wood mice and reduces their reproductive output. The authors quantified transmission dynamics in mixed populations of these rodents by analyzing time‑series of susceptible, infectious, and newly infected individuals and estimating species‑specific transmission coefficients to assess annual and seasonal variation. Within‑species transmission is frequency dependent rather than density dependent, while interspecies transmission is negligible, affecting reservoir potential and apparent competition.

Abstract

The transmission dynamics of the cowpox virus infection have been quantified in two mixed populations of bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus), through analyses of detailed time-series of the numbers of susceptible, infectious and newly infected individuals. The cowpox virus is a zoonosis which circulates in these rodent hosts and has been shown to have an adverse effect on reproductive output. The transmission dynamics within species is best described as frequency dependent rather than density dependent, contrary to the 'mass action' assumption of most previous studies, both theoretical and empirical. Estimation of a transmission coefficient for each species in each population also allows annual and seasonal variations in transmission dynamics to be investigated through an analysis of regression residuals. Transmission between host species is found to be negligible despite their close co–habitation. The consequences of this for the combining ability of hosts as zoonotic reservoirs, and for apparent competition between hosts, are discussed.