title: Disease dynamics in cyclic populations of field voles (Microtus agrestis): cowpox virus and vole tuberculosis (Mycobacterium microti).
abstract: The possible role of pathogens in rodent population cycles has been largely neglected since Elton's 'epidemic hypothesis' of 1931. To revisit this question, 12 adjacent, cyclic but out-of-phase populations of field voles (Microtus agrestis) in North East England were studied and the initial results are presented here. The prevalences of antibodies to cowpox virus and of clinical signs of Mycobacterium microti infection (vole tuberculosis) showed delayed (not direct) density dependence (with a lag of three to six months). This did not result from changes in population structure, even though there were such changes associated with the different phases of the cycle. The prevalences rose as vole numbers rose, and peaked as numbers declined. The apparent lag in the numerical response of infection prevalence to changes in host abundance is consistent with the hypothesis that diseases, singly or in combination, play a hitherto underestimated role in the dynamics of cyclic populations.
authors.affiliation: Centre for Comparative Infectious Diseases, University of Liverpool, Biosciences Building, Liverpool L69 7ZB, UK. rachel.cavanagh@ssc-uk.org
authors.forename: Rachel D
authors.initials: RD
authors.lastname: Cavanagh
authors.forename: Xavier
authors.initials: X
authors.lastname: Lambin
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Ergon
authors.forename: Malcolm
authors.initials: M
authors.lastname: Bennett
authors.forename: Isla M
authors.initials: IM
authors.lastname: Graham
authors.forename: Dick
authors.initials: D
authors.lastname: van Soolingen
authors.forename: Michael
authors.initials: M
authors.lastname: Begon
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D003411:Arvicolinae; D001824:Body Constitution; D015605:Cowpox / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D015608:Cowpox virus / Q000276:immunology*; D004739:England / Q000453:epidemiology; D005455:Fluorescent Antibody Technique; D016014:Linear Models; D009161:Mycobacterium; D011157:Population Dynamics; D015995:Prevalence; D012376:Rodent Diseases / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology / Q000821:virology; D013997:Time Factors; D014376:Tuberculosis / Q000453:epidemiology / Q000662:veterinary*
chemical_list: D000914:Antibodies, Viral