Diseases and host dynamics are linked, but their associations may vary in strength, be time-lagged, and depend on environmental influences. Where a vector is involved in disease transmission, its dynamics are an additional influence, and we often lack a general understanding on how diseases, hosts and vectors interact. We report on the occurrence of six zoonotic arthropod-borne pathogens (Anaplasma, Bartonella, Borrelia, Coxiella, Francisella and Rickettsia) in common voles (Microtus arvalis) throughout a population fluctuation and how their prevalence varies according to host density, seasonality and vector prevalence. We detected Francisella tularensis and four species of Bartonella, but not Anaplasma, Borrelia, Coxiella or Rickettsia. Bartonella taylorii and B. grahamii prevalence increased and decreased with current host (vole and mice) density, respectively, and increased with flea prevalence. Bartonella doshiae prevalence decreased with mice density. These three Bartonella species were also more prevalent during winter. Bartonella rochalimae prevalence varied with current and previous vole density (delayed-density dependence), but not with season. Coinfection with F. tularensis and Bartonella occurred as expected from the respective prevalence of each disease in voles. Our results highlight that simultaneously considering pathogen, vector and host dynamics provide a better understanding of the epidemiological dynamics of zoonoses in farmland rodents.
Bibliographical noteSupplementary material. The supplementary material for this article can
be found at https://doi.org/10.1017/S0031182018001543
Acknowledgements. We thank José Luis Guzman for helping with fieldwork
and Fabio Flechoso for helping with ectoparasite counts and flea
Financial support. R.R.P. was supported by a Ph.D.-studentship from the
University of Valladolid (co-funded by Banco Santander, RR 30/04/2014).
This work was supported by ECOCYCLES (Partner 5 –EUI2008-03658),
ECOVOLE (CGL2012-35348), ECOTULA (CGL2015-66962-C2-1-R) and
RESERTULA (CLG2015-66962-C2-2-R) projects funded by Ministerio de
Economía y Competitividad, Government of Spain.