Social group size affects Mycobacterium bovis infection in European badgers (Meles meles)

• Published in: The Journal of animal ecology Vol. 78; no. 4; pp. 818 - 827
• Main Authors: Woodroffe, Rosie, Donnelly, Christl A, Wei, Gao, Cox, D.R, Bourne, F. John, Burke, Terry, Butlin, Roger K, Cheeseman, C.L, Gettinby, George, Gilks, Peter, Hedges, Simon, Jenkins, Helen E, Johnston, W. Thomas, McInerney, John P, Morrison, W. Ivan, Pope, Lisa C
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2009; Blackwell Publishing; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal diseases; Animal ecology; Animal populations; Animal, plant and microbial ecology; Animals; Badgers; Behavior, Animal; Biological and medical sciences; Body Weight; bovine tuberculosis; cattle TB; Culling; Disease transmission; Ecosystem; Epidemiology; Female; Fundamental and applied biological sciences. Psychology; General aspects; Group size; Host-Pathogen Interactions; Human ecology; Infections; Male; Mammalia; Mammals; Meles meles; Mustelidae; Mycobacterium bovis; Mycobacterium tuberculosis; Parasite and Disease Ecology; Pastures; Population density; Population Dynamics; Prevalence; Social Behavior; Social groups; Time Factors; Tuberculosis - veterinary; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; wildlife disease; wildlife diseases; wildlife host; Europe; Disease; Social group; Mycobacterial infection; Bacteria; Ungulata; Fissipedia; Carnivora; bovine tuberculosis; Bovine; Mycobacterium bovis; Group size; Host; Wild life; Infection; wildlife disease; wildlife host; Vertebrata; Mammalia; Tuberculosis; Meles meles; Mycobacteriales; Bacteriosis; Mycobacteriaceae; cattle TB; Actinomycetes; Artiodactyla
• ISSN: 0021-8790; 1365-2656
• DOI: 10.1111/j.1365-2656.2009.01545.x

1. In most social animals, the prevalence of directly transmitted pathogens increases in larger groups and at higher population densities. Such patterns are predicted by models of Mycobacterium bovis infection in European badgers (Meles meles). 2. We investigated the relationship between badger abundance and M. bovis prevalence, using data on 2696 adult badgers in 10 populations sampled at the start of the Randomized Badger Culling Trial. 3. M. bovis prevalence was consistently higher at low badger densities and in small social groups. M. bovis prevalence was also higher among badgers whose genetic profiles suggested that they had immigrated into their assigned social groups. 4. The association between high M. bovis prevalence and small badger group size appeared not to have been caused by previous small-scale culling in study areas, which had been suspended, on average, 5 years before the start of the current study. 5. The observed pattern of prevalence might occur through badgers in smaller groups interacting more frequently with members of neighbouring groups; detailed behavioural data are needed to test this hypothesis. Likewise, longitudinal data are needed to determine whether the size of infected groups might be suppressed by disease-related mortality. 6. Although M. bovis prevalence was lower at high population densities, the absolute number of infected badgers was higher. However, this does not necessarily mean that the risk of M. bovis transmission to cattle is highest at high badger densities, since transmission risk depends on badger behaviour as well as on badger density.