OJD Prevalence Areas in Australia
IMPORTANT INFORMATION – READ THIS
On January 1 some Prevalence Areas changed. To claim a particular Prevalence Area status, a jurisdiction has to consistently demonstrate that the area flock prevalence is below the maximum cut off for that Prevalence Area at the 95% confidence limit for two consecutive years. If it exceeds the cut-off for two consecutive years, its status may be reclassified. View the current cut off limits
Several OJD Prevalence Areas exceeded the agreed limits in 2008 and 2009 and subsequently some Prevalence Areas have now changed to ensure area prevalence reflects the true risk associated with buying sheep from those regions.
From 1 January 2011 the following changes have been made.
| State | Status in 2010 | ABC points in 2010 | Status from 1 January 2011 | ABC Points from January 2011 |
|---|---|---|---|---|
| Victoria | Medium Prevalence Area | 2 | High Prevalence Area | 0 |
| Low Prevalence Area | 4 | Medium Prevalence Area | 2 | |
| Western Australia | Low Prevalence Area | 4 | Medium Prevalence Area | 2 |
| New South Wales | Boundaries to the Low, Medium and High Prevalence Areas have changed: OJD Prevalence Area Map from January 2011- NSW |
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There are no changes to prevalence areas in South Australia, Queensland or Tasmania.
What are the prevalence areas?
‘Prevalence Areas’ are regions defined by the proportion of flocks in the region that are estimated to be infected with OJD, based on the results of ongoing abattoir surveillance. Monitoring of sheep for OJD and other endemic conditions occurs nationally. In line with nationally agreed protocols, the surveillance data is analysed annually to provide additional information on area prevalence.
Prevalence Areas, which form a key component of the Assurance Based Credit Scheme, have been defined using the abattoir surveillance data collected by each state and published in surveillance reports over a number of years. Each point allocated under the ABC Scheme represents a fourfold decrease in likelihood of infection being acquired from that particular line of sheep, that means the more points a line of sheep has, the lower the risk they represent.
There are three OJD Prevalence Areas recognised in Australia. These are:
- Low Prevalence Area (LPA)
- Medium Prevalence Area (MPA)
- High Prevalence Area (HPA)
Producers should be aware that if purchasing unvaccinated sheep from the High and Medium prevalence areas, there is a high probability that at least some of the sheep may be infected with ovine Johne’s disease.
You can view the current maps effective from 1 January 2011 here:
OJD Prevalence Area Map from January 2011 – Australia
OJD Prevalence Area Map from January 2011- NSW
OJD Prevalence Area Map from January 2011- VIC
Currently there are no areas where OJD is not known to exist in Australia.
For more information on OJD Prevalence Areas contact your State Coordinator.
Page Updated: 24 December 2010