Wisconsin Bovine TB Update

Transcription

1 Wisconsin Bovine TB Update Dr. Darlene Konkle Assistant State Veterinarian Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) Division of Animal Health

2 Mycobacterium species M. tuberculosis #1 human infection worldwide known to infect zoo animals M. bovis Wide host range infects most mammals / very infectious

3 Bovine TB: US History 1910s Milk pasteurization, meat inspection begins National eradication program begins ~5% of all US cattle infected with TB 1922 mandatory Cost to industry est. $40 Million

4 Bovine TB: Control / Eradication Federal USDA APHIS Veterinary Services State Wisconsin Department of Agriculture, Trade and Consumer Protection

5 Bovine TB: The Bacteria M. bovis Gram variable rods Non-motile Intracellular Survives well in macrophages Fastidious growth requirements Lipid-rich cell wall Acid Fast

6 Bovine TB: Transmission Inhalation Aerosol from other infected animals Ingestion Unpasteurized milk, contaminated feed/food

7 Bovine TB: Clinical Signs in Cattle Most cattle appear healthy can be asymptomatic for years, yet infectious Long incubation period Advanced infections Loss in body condition Lymphadenopathy, intermittent fever (rare) Chronic cough, nasal discharge (rare)

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9 How do we find btb-affected herds? 2) Epidemiologic tracing 1) High Risk Area onfarm testing ) Slaughter trace back 4) Routine on-farm testing

10 Challenges to US TB Eradication Wildlife Undetermined sources New WGSs Human transmission Mexican feeders & ropers Movement Slaughter detection Poor Traceability Changes in cattle production Larger herds Heifer raisers Decreased regulatory budgets Indemnity changes

11 WI Bovine TB Current Situation September 28, 2018: NVSL notifies DATCP of bovine TB positive cow at slaughter Histocompatible & PCR positive 840 tag traced back to a Dane Co dairy Dane Co dairy quarantined, whole herd TB test of all animals over 2 months of age performed CFT, CCT and gamma interferon testing used to prioritize animals for further testing

12 WI Bovine TB Current Situation October 29, 2018: NVSL confirms 2 positive animals from herd (histocompatible and PCR positive) confirmation of TB affected herd status for Dane Co dairy herd 48 animals classified as reactors (CFT responders) from the initial whole herd tests Total of five positive animals removed from herd

13 WI Bovine TB positive herd Strain of bovine TB isolated from the cow at slaughter matches the strain isolated from a human patient in WI in 2015 WI Public Health contacted DATCP in 2015 regarding possible herd exposure Whole herd tests were negative for TB in 2015 Genetic sequencing results for the positive animals removed directly from the herd also match this strain.

14 WI Bovine TB positive herd Next Steps USDA will initiate an epidemiological model to characterize the herd Prevalence within herd Risk of disease transmission Efficient methods to eliminate TB from herd Availability of federal indemnity funds Depopulation vs. Test and Removal strategy for elimination of TB

15 WI Bovine TB trace investigations Trace ins Purchases past 5 years Trace outs Sales past 5 years Priority given to animals leaving herd recently Breeding Animals/exposure Test Herd, Remove exposed Herd plan Feeders Restricted movement to slaughter only

16 Minimize Risk to WI Producers Review Risk Factors What comes in to herd? Purchases Commingling of heifers at off-site locations What precautions are in place? TB testing of source herds/ animals TB accredited herd status less common, because most states have TB free status Biosecurity plans

17 Contingency Planning Long term quarantine Heifers Off site rearing Bull calves Housing Feeding Permitted movements to slaughter Depopulation/Test and Removal Emotional/Financial impacts

18 Questions? Questions?