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Surveillance for Bovine Tuberculosis in U.S. Livestock. Tuberculosis Eradication Program Ruminant Health Programs Updated April 28, 2009. Overview. Affected herds Slaughter surveillance Slaughter inspection Granuloma lesions submitted for histopathology Mexico origin cases
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Surveillance for Bovine Tuberculosis in U.S. Livestock Tuberculosis Eradication Program Ruminant Health Programs Updated April 28, 2009
Overview • Affected herds • Slaughter surveillance • Slaughter inspection • Granuloma lesions submitted for histopathology • Mexico origin cases • Live animal surveillance • Tuberculin skin testing • Gamma interferon testing • M. bovis in swine, Molokai Island, Hawaii
Affected Herds*FY 2000–2009, United States *80 herds - 64% beef, 28% dairy, 2% mixed, 5% captive cervid
Affected HerdsBy State, FY 2000–2009 Affected Herds *81 herds - 64% beef, 28% dairy, 2% mixed, 5% captive cervid
Live Animal vs. Slaughter Surveillance — Finding Affected Cattle Herds, U.S., FY 2000–2009 Michigan, Minnesota (54) Rest of U.S. (28) Total affected cattle herds: 75 *No herd: 7 adult slaughter cases from California, Texas, Nebraska, New Mexico, South Dakota — no affected herd was detected
Granuloma Submissions from U.S. Slaughter Plants, 2000–2008 Submissions Fiscal Year
Granuloma Submission Rates for Slaughtered Adult Cattle, 2000–2008 Submissions continue to exceed target! Target: 5/10,000 adult cattle slaughtered Target Rate Fiscal Year
Granuloma Lesion Submission in “Top 40”Adult Cattle Slaughter Plants, FY 2008 • 5 lesions/10,000 killed (33) < 5 lesions/10,000 killed (7) - 133% increase from FY07 PR AK HI VI Modified accredited advanced status Modified accredited status
M. bovis Positive Cattle From Slaughter Tissue Sample Submissions, 2001–2009 358 TB cases in 9 years!! Updated 4/28/2009
Confirmed Cases of M. bovis from Slaughter Surveillance, FY 2009 • 18 positive by histology • 17 cattle cases • 11 confirmed M. bovis • PCR or culture • 5 – other Mycobacterium • M. avium (4), M. kansasii (1) • 1 – PCR negative, no culture • 1 confirmed M. bovis – captive elk Updated 4/28/2009
Confirmed Cases of M. bovis from Slaughter Surveillance, FY 2009 • 6 adult cases • 3 from 1 MN buyout herd • North Dakota – infection not confirmed in herd • PA slaughter case – no ID, multiple traces/states under investigated • NE adult beef cow under investigation (new) • 1 captive elk, NE – herd confirmed infected • 5 cases in fed cattle • 2/5 (40%) Mexican origin • 1 – Chihuahua • 1 – Veracruz • 1 – roping steer SE US • 2 – under investigation Updated 4/28/2009
Confirmed Cases of M. bovis from Slaughter Surveillance, FY 2008 • 42 cattle positive by histology • Of these, • 34 – confirmed M. bovis (PCR, culture) • 6 – other Mycobacterium • M. avium [5], M. intracellulare [1] • 2 – negative
Confirmed Cases of M. bovis from Slaughter Surveillance, FY 2008 • 1 adult case, CA • 33 cases in fed cattle • 9/33 (27%) Mexican origin • 4 – Chihuahua, 2 – Coahuila, 2 – Tamaulipas • 1 – under investigation • 2 from Canada • 19 – Feedlot, TX • 1 – Domestic case, NE MN • 3 – Investigation pending
Location of 34 Cattle Positive for M. bovisDetected at SlaughterOctober 1, 2007–September 30, 2008 19 TX feedlot cases—assembled from KS/OK sales 33 fed 1 adult
Outbreak of TB in TX FeedlotFY 2008 • 19 TB cases in two feeder groups • Origin of cattle were old rodeo steers (many “M” branded) assembled from sales in OK and KS • Infected steers exposed 3,000 heifers backgrounding in same feedlot (shared hospital pen) • Epi tracing completed for 300–600 heifers potentially exposed
Genotyping in Epidemiologic Investigations Analysis of differences in nucleic acid sequences between strains of same species • Spoligotyping • Fast, but lacks discriminatory ability • RFLP–IS6110, PGRS (two types) • High discrimination, technically demanding, pattern comparison difficult when many strains • Mycobacteria Laboratory, NVSL is routinely genotyping M. bovis strains to assist investigations
Genotyping Results, FY 2008 • California, three affected herds • Strain isolated from Herd 2 different from Herds 1 and 3 • CA, TX slaughter cases, 2 cases from Campeche • Herds 1 and 3, strain identical • Most similar to CA slaughter case FY97 and NM affected herd FY 08 • Feedlot outbreak with 19 affected cattle • All isolates identical — point source outbreak • Retired roping/rodeo cattle • Strains occurs infrequently in database — most similar to MX origin slaughter cases and untraceable SD case FY 05 • New York deer • Close match to early 1990’s NY cervid strains • Comparison of MN strains, 2005–2008 • From deer and cattle • All strains identical or minor variations
TB Cases Identified per 100,000 Cattle Imported from Mexico, 1995–2008
Cattle Imports from MexicoBy Import Cycle Year* 2003–2007 *Import cycle year ending August 31 Data source: Mexican Cattlemen’s Association
Origin of Eight TB Cases with Mexican Eartags, FY 2008 Reviewed! 2 4 2
Caudal Fold Test PerformanceCattle and Bison, FY 2006–2008 *As of October 15, 2008, 48 States
Caudal Fold Test Results in CattleBy State,* FY 2008 < 0.05% in 6 States; 25,000 cattle State *States with > 300 tests (n=1,366,004 tests, 47 States and Puerto Rico) Source: AWBDS and States
Bovine Gamma Interferon TestingFY 2006–2008 FY 2008 • 15,601 tests • Includes repeat testing of individuals • 94% of tests for cattle from 5 States • CA, MI, MN, NM, TX • Cattle tested from 20 states • Approved testing labs unchanged: TX, MI, CA, NVSL Annual tests by fiscal year, 2006-2008
Bovine Interferon Gamma TestingFY 2008 • Increase in positives beyond expected • Spring 2008, two labs, dairy cattle—CA, NM • Avian tuberculin—new lot with decreased ability to stimulate cells during assay • Above does not fully explain findings • Additional hypotheses include “real” immune phenomena in cattle, conditions after sample drawn • Invalid results–cells do not stimulate • Rare, but requires repeated gamma testing or CCT to resolve • Manufacturer (Prionics) has identified need to find new source for stimulating bovine and avian antigens • Once antigen source identified, plan to evaluate new antigens side-by-side with currently used antigens • Currently, antigens sourced from Australia (CSL)
Bovine Interferon Gamma Test ResultsBy Testing Laboratory, FY 2008
Tuberculin Testing of Cervids FY 2006–2008 Source: AWBDS; as of October 8, 2008 for FY 2008
Surveillance for M. bovis in Feral Swine, Molokai Island, Hawaii, FY 2007–2008 • 2008: tissues submitted for 59 animals; 7 confirmed* • 2007: 6 confirmed* • Feral swine reservoir • Cattle continue to test negative *Confirmed by PCR or culture
Thank You Questions or Comments? Lymph node, culture positive for M. bovis