The spatio-temporal distribution of Mycobacterium bovis (bovine tuberculosis) infection in a high-density badger population

1. The European badger (Meles meles) is implicated as a reservoir of Mycoba cterium bovis (bovine TB) infection for cattle in Britain and Ireland. In t he present study the spatio-temporal distribution of M. bovis infection was investigated. Analyses were carried out on data from a long-term epidemiol ogical and ecological study of the dynamics of bovine TB in a wild populati on of badgers at Woodchester Park in south-west England. 2. During the 15 years of the capture-mark-recapture study (1982-96), 3316 trapping and post-mortem records were obtained from 1270 individual badgers . Annual prevalence of infection based on positive serological and bacteria l tests varies between 10.3% and 17.7% of the population. 3. Infection was aggregated in social groups in the west of the study area, confirming the findings of previous studies. However, temporal trends in d isease were not synchronized amongst neighbouring groups, suggesting low ra tes of disease transfer between them. 4. There was significant serial correlation in the disease status within gr oups over time, suggesting that infection persists for many years in some s ocial groups. The presence of infectious adult female badgers in groups was associated with new infections, and provides further evidence for their im portance in the maintenance of infection within groups. However, no statist ically significant correlations were detected between the demographic chara cteristics of social groups and group infection status. 5. The distribution of disease reflects stable persistent foci of infection in the badger population, with limited evidence of transfer between social groups. The accurate identification of stable foci of infection would allo w a range of management strategies for the control of bovine TB to be effic iently targeted in such populations. However, the extent to which this patt ern of infection is representative of low-density and disturbed badger popu lations is unknown.