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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
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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 • 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
Test and Slaughter
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 water buffalo
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
NT 1999 Qld 2000 WA 1998 SA 1996 NSW 1995 Vic 1991 Last TB Case in Cattle Tas 1975
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