Brucellosis in Northern Ireland (1960s - Compulsory eradication)

The history of Brucellosis in Northern Ireland during the 1960s in relation to compulsory eradication.

A compulsory eradication scheme for dairy herds was introduced in January 1963. Letters were sent to all herd owners explaining details and procedures of the Brucellosis Scheme. Milk samples collected by the creameries were submitted and tested at 6-monthly intervals. Where three consecutive clear tests were obtained, these herds were placed on the register. Failing this, one blood sample was sufficient if clear.

Adult vaccination with S19 vaccine was discontinued and only calves aged 4 to 8 months were allowed to be vaccinated. The main effort at the outset of the eradication programme was directed towards those dairy herds from which milk samples taken at creameries had proved to be positive and those dairy and breeding herds which showed clinical evidence of infection (in other words, abortions).

The objective was to deal with known infection at source as quickly as possible thus curtailing spread within these herds and preventing its spread to neighbouring herds. Other herds were also tested on a geographical pattern. The testing of all dairy herds showed that about 20% were infected. This was a much higher level than had been indicated by the survey based on milk churn supplies to milk depots in 1962. The testing of all breeding herds showed that the results of the survey based on the serum agglutination test had provided a reasonably accurate estimate of the level of infection in those herds.