BSE IN NORTHERN-IRELAND - EPIDEMIOLOGIC PATTERNS PAST, PRESENT AND FUTURE

By 30 January 1998, there had been 170 259 confirmed cases of BSE in G reat Britain (GB), 1766 confirmed cases in Northern Ireland (NI) (2 Ja nuary 1998), and 276 confirmed cases in the Republic of Ireland (31 Ja nuary 1998). Analysis of the epidemiological patterns in the NI epidem ic reveals significant clustering of cases in herds and counties. The observed clustering of cases within herds results in lower per capita incidence of BSE in previously unaffected herds, providing support for the introduction of a certified herd scheme in NI. By fitting a backc alculation model to the case data, we can estimate the number of anima ls infected with the aetiological agent of BSE and project the number of future cases. We predict that the epidemic will decline rapidly, wi th approximately 99 cases (95% confidence interval: 30, 504) occurring in the five year period 1997-2001.