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SURVEILLANCE AND RISK MANAGEMENT DURING THE LATTER STAGES OF ERADICATION AUSTRALIA BRIAN RADUNZ. NT. Qld. WA. SA. NSW. Vic. Tas. Darwin. Great Barrier Reef. Ayers Rock. Perth. Sydney. Eastern and Southern Australia farming areas 150,000 properties - PowerPoint PPT Presentation
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SURVEILLANCE AND RISK
MANAGEMENT DURING THE
LATTER STAGES OF ERADICATION
AUSTRALIA
BRIAN RADUNZ
Qld
NSW
SA
WA
Vic
Tas
NT
Darwin
Ayers Rock
Great Barrier
Reef
Sydney
Perth
Eastern and Southern Australia
• farming areas
• 150,000 properties
• small herd size (<100 average)
• some herds up to 2000 - 3000 head
• TB free by mid 1980s
TB eradication by standard test and slaughter techniques
•Europe
•North America
•New Zealand
Central and Northern Australia
Extensive grazing
• < 2000 properties
• large herd size (5000-50,000)
• large property size (3-10 head per sq km)
• 2000 - 15000 sq kms
TB ERADICATION
•Paddocks
• Bush area
(uncontrolled parts of property)
• test and slaughter
• weaner segregation
• paddock checks
• destocking (age and bush)
• completion of destocking
New Steel Yard
AGE DESTOCKING
higher prevalence aged cows and bulls in controlled areas (early in campaign)
BUSH DESTOCKING
all cattle from bush areas
(uncontrolled areas)
BREAKDOWN DESTOCKING
exposed cattle (later in campaign)
in response to a breakdown
Bush Destocking
•muster (3-5 years)
•chopper shooting (1-2 years)
•radio tracking (5-7 years)
Radio tracking to complete destocking
JUDAS ANIMALS
FERAL PIGS
• very common on the flood plains near Darwin
• TB (M. bovis) in feral pigs is closely associated with TB infected cattle and buffalo
• No TB found in pigs since infected cattle and buffalo removed
• Strong evidence that in the Northern Territory the feral pig is an end-host
McInerney et al 1995, Australian Veterinary Journal, 72: 448-451
Risk Management and field surveillance during latter stages of the campaign
• Increasing TB testing prior to quarantine release
• Additional surveillance testing after quarantine release
• Destocking exposed cattle as the primary eradication tool
• TB testing used to confirm that low risk cattle were not infected
HERD TB STATUS PROGRESSION
Infected
whole herd negative test (>60 days)
Restricted
whole herd negative test at least 6 months later
Provisionally Clear (QR1)
whole herd negative test at least 6 months later
Confirmed Free 1(QR2)
whole herd negative test at least 12 months later
Confirmed Free 2 (QR3)
negative test of exposed animals within 8 years
Confirmed Free 3
In 1999 the Confirmed Free 3 surveillance was replaced with additional risk management and accelerated commercial slaughter
• incentives and disincentives applied
• financial assistance to accelerate slaughter of exposed cows
• reduced financial assistance in the event of a TB case if no compliance
Herds infected with TB from 1 January 1988 to 31 December 1999 and NOT
totally destocked
Older than 12 months at exposure
Less than 12 months at exposure
Category A cattle Category B cattle
Annual TB test of cattle and any in-contact cattle
until slaughter
TB test of cattle and any in-contact cattle every 2
years until slaughter
Primary cases of tuberculosis from 1993 - 2002
1993 8
1994 7
1995 8
1996 6
1997 7
1998 4
1999 1
2000 1 Last TB in cattle
2001 0
2002 2 Two adjacent water buffalo herds
BTEC
TFAP
Qld2000
NSW1995
SA1996
WA1998
Vic1991
Tas1975
NT1999
Last TB Case in Cattle
Abattoir Surveillance
National Granuloma
Submission Program
(NGSP)
• To increase the sensitivity of the abattoir monitoring system
• Started late 1992
• ALL granulomas submitted to laboratory
• 8-9 M cattle slaughtered annually
1993 - 97 1998-2002
Kills Ms 36.3 41.1
Granulomas 12992 21148
TB detected 57 10*
* 2 Clusters each with 3 primary cases in each cluster
NGSP2
• Targeted NGSP
• Started October 2002
• Phased in introduction - based on date of last TB case
• Very low risk States
• meat inspector to submit granuloma only if unsure of the cause
• Low risk States
• granulomas from head and thorax only
• From January 2007 in all States inspectors will
submit only granulomas if unsure of the cause
• From 2007 TB exclusion will be part of general
surveillance
Origin of granulomas
%
Thorax 23
Head 72
Abdomen 3
Other 2
Diagnosis of granulomas during TFAP (1998 - 2002)
%
Actinobacillosis 49
Rhodococcus 12
Neoplasm 7
Parasitic 4
Fungal 2
Nocardia 1
Other 20
No Diagnosis 5
Tuberculosis 0.04
REASONS FOR SUCCESS IN ERADICATION
• strong government and industry support
• joint industry and government funding and decision making
• industry funded 50%
• strong technical basis
• no wildlife reservoir hosts
• consistent implementation
• risk manage exposed cattle in latter stages of the campaign
• granuloma submission program in latter stages of the program