title: Cowpox virus infection in natural field vole Microtus agrestis populations: delayed density dependence and individual risk.
abstract: 1. Little is known about the dynamics of pathogen (microparasite) infection in wildlife populations, and less still about sources of variation in the risk of infection. Here we present the first detailed analysis of such variation. 2. Cowpox virus is an endemic sublethal pathogen circulating in populations of wild rodents. Cowpox prevalence was monitored longitudinally for 2 years, in populations of field voles exhibiting multiannual cycles of density in Kielder Forest, UK. 3. The probability that available susceptible animals seroconverted in a given trap session was significantly positively related to host density with a 3-month time lag. 4. Males were significantly more likely to seroconvert than females. 5. Despite most infection being found in young animals (because transmission rates were generally high) mature individuals were more likely to seroconvert than immature ones, suggesting that behavioural or physiological changes associated with maturity contribute to variation in infection risk. 6. Hence, these analyses confirm that there is a delayed numerical response of cowpox infection to vole density, supporting the hypothesis that endemic pathogens may play some part in shaping vole cycles.
authors.affiliation: Population and Evolutionary Biology Research Group, School of Biological Sciences, University of Liverpool, Liverpool, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Burthe
authors.forename: Sandra
authors.initials: S
authors.lastname: Telfer
authors.forename: Xavier
authors.initials: X
authors.lastname: Lambin
authors.forename: Malcolm
authors.initials: M
authors.lastname: Bennett
authors.forename: David
authors.initials: D
authors.lastname: Carslake
authors.forename: Andrew
authors.initials: A
authors.lastname: Smith
authors.forename: Michael
authors.initials: M
authors.lastname: Begon
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D003411:Arvicolinae / Q000097:blood / Q000821:virology*; D001835:Body Weight; D015605:Cowpox / Q000453:epidemiology / Q000662:veterinary*; D015608:Cowpox virus / Q000302:isolation & purification*; D005260:Female; D008297:Male; D011156:Population Density; D015995:Prevalence; D016036:Seroepidemiologic Studies; D012727:Sex Characteristics; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral