A small number of cases could be found over the coming seasons

Figure 1: Phases to eradicate M. bovis

The programme is now into its fifth year of an estimated 10-year plan to eradicate M. bovis.

Figure 1 shows the path towards eradication has three distinct phases of eradication — ‘Delimiting’, ‘Provisional Absence’ and ‘Confidence of Absence’.

1. ‘Delimiting’ is the first phase during which cases of infection are identified and removed.
2. The ‘Provisional Absence’ phase can begin after all active cases are resolved. This is likely to take two and a half years of intensive surveillance where no new infected cases are found.
3. ‘Confidence of absence’ is where a formal case is made to the relevant international bodies presenting New Zealand’s evidence that M. bovis has been eradicated.

 
Figure 2: Epidemic curve for M. bovis in New Zealand

Figure 2 shows the M. bovis programme has effectively controlled most of the infection that has occurred in New Zealand.

Evidence supports that we are nearing the end of the Delimiting phase where we will be working harder to find the remaining pockets of infection.

Due to the nature of the disease and its ability to remain clinically undetected, it is likely small numbers of additional cases could be found over the coming seasons.

Once these are dealt with, we will enter the Provisional Absence phase.