Ovine Johnes Disease Prevalence Areas

Note Number: AG1125
Published: January 2006
Updated: October 2009

This Agriculture Note describes OJD Prevalence Areas and how they apply to Sheep Health Statements. Under the Assurance Based Credit (ABC) Scheme for OJD, every state in Australia has been assigned one or more Prevalence Areas. Prevalence Areas are based on the estimated percentage of flocks affected by OJD in the area.

What are the Prevalence Areas?

There are three different Prevalence Areas nationally. These are:

High Prevalence (more than 12.5% of flocks infected)
Medium Prevalence (0.8-12.5% of flocks infected), and
Low Prevalence (less than 0.8% of flocks infected).

How are Prevalence Areas defined?

Prevalence Areas are determined and monitored nationally based on the results of abattoir monitoring and the number of known infected flocks in the area.

fig 1. Map of Aust showing OJD prevelance area for implementation from 31 March 2008

As of 31 st March 2008, Victoria has been divided into two Prevalence Areas: a Low Prevalence Area and a Medium Prevalence Area. The following shires are included in the Low Prevalence Area: Mildura, Swan Hill, West Wimmera, Glenelg, Gannawarra, Yarriambiack, Buloke, Horsham and Hindmarsh. All other Victorian shires are in the Medium Prevalence Area.

Fig 2. Map of Victoria showing Prevalence area of implementation from 31 March 2008

Why are Prevalence Areas important?

Under the Assurance Based Credits (ABC) Scheme, points are awarded in Category A of the Sheep Health Statement (SHS) based on Prevalence Areas. These points contribute to a flock or mobs ABC Score. Flocks in the Low Prevalence Area (excluding infected and suspected to be infected flocks) flocks may claim 4 credit points in Category A of their SHS. Flocks in the Medium Prevalence Area (excluding infected and suspected to be infected flocks) may claim 2 credit points in Category A of their SHS. Infected and suspected to be infected flocks cannot claim any credits in Category A, but may gain credits in other categories through testing, vaccination and risk assessments.

Further information

Further information about OJD can be obtained from animal health staff at your local DPI office or on the DPI web site http://www.dpi.vic.gov.au/farming/OJD

Acknowledgements

This Agriculture Note was developed by Dr Martin Roche, Field Services Victoria January 2006.

It was reviewed by Dr David Champness, Biosecurity Victoria Animal Standards Branch October 2009.

ISSN 1329-8062

Published and Authorised by:
Department of Primary Industries
1 Spring Street
Melbourne, Victoria

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