LIVESTOCK/WILDLIFE INTERFACE AND ITS IMPACTS ON FOOD ANIMAL HEALTH Craig Shultz Bureau of Animal Health and Diagnostic Services Pennsylvania Department of Agriculture

Diseases Common to Livestock and Wildlife Many Diseases, Many Species Deer and other Cervidae Bovine Tuberculosis Bovine Brucellosis Epizootic Hemorrhagic Disease Commercial cattle industry at risk Feral Swine Pseudorabies Swine Brucellosis Classical Swine Fever Commercial Swine industry at risk Wild Birds, especially waterfowl Avian Influenza Commercial poultry industry at risk

The Principal Concern Diseases that establish in a wildlife population and that population in turn serves as a reservoir for livestock disease with potential negative impact on the food supply and public health. Epizootic Hemorrhagic Disease in Deer and Cattle

Objective of this presentation To consider a well-established example of a significant livestock disease with a wildlife reservoir To explore lessons learned for future policymaking Example for today’s discussion: Wildlife (Cervid) Reservoir of Mycobacterium bovis (Bovine Tuberculosis) in the State of Michigan

Bovine Tuberculosis Mycobacterium bovis An insidious chronic disease with significant animal health and public health concerns A part of the Mycobacterium tuberculosis complex Mycobacterium tuberculosis complex includes Mycobacteria that cause human TB including Mycobacterium tuberculosis The disease often goes unnoticed in cattle and deer herds for long periods of time as clinical signs can be slow to develop. In the past, considered a wasting disease with clinical signs and post mortem lesions predominantly in older cattle (“old dairy cow disease”) More recently significant numbers of beef cattle and younger cattle are found with lesions at slaughter.

Brief History of Bovine TB Eradication in the United States At the turn of the 20 th Century – Upton Sinclair’s exposé The Jungle on abuses in the packing industry brought attention to the high incidence of tuberculous animals in US slaughter channels.

Brief History of Bovine TB Eradication in the United States US TB eradication program initiated in 1917 with surveillance based on area tuberculin testing with purified protein derivative (ppd) of Mycobacterium bovis

Brief History of Bovine TB Eradication in the United States Infection rates steadily declined through the 20 th century Nearly all states gained USDA, APHIS Bovine TB-free status by the early 1990’s Infection rates estimated at 0.02% nationwide since the 1990’s estimated 5% of slaughter cattle were infected % infection rate % infection rate

Brief History of Bovine TB Eradication in the United States As infection rates declined to very low levels in the 1990’s surveillance shifted from area tuberculin testing to slaughter granuloma surveillance

Public Health Impact of Mycobacterium bovis Infection At the beginning of the Bovine TB Eradication Effort in the US (1917) it was estimated that 20% of the human tuberculosis cases were the result of Mycobacterium bovis infection. Primarily due to consumption of unpasteurized dairy products. Today less than 2% of human TB cases in the United States are the result of Mycobacterium bovis infection _ ,00.html

Michigan A Case Study of Bovine TB in a Wildlife Reservoir As national eradication efforts progressed, Michigan was declared Bovine Tuberculosis-Free by USDA in In 1975 a white tailed deer in Alcona County Michigan was diagnosed with bovine TB In 1993 slaughter surveillance samples from a cow in Isabella County tested positive for Mycobacterium bovis follow-up testing of 70 additional cattle herds yielded no positives.

Michigan Bovine TB Chronology In late 1994 a white tailed buck harvested during rifle season in Alcona County tested positive for M. bovis 1995 – all cattle herds within a 5 mile radius of the Alcona County positive deer were tested. Also 14 additional deer were collected in the area. All cattle and deer were negative June 1995 – Montcalm County Elk herd tests positive for TB. This was strain of TB was not consistent with other Michigan cattle and deer positives. Deer surveillance negative

Michigan Bovine TB Chronology Presque Isle County captive deer herd identifies deer with lesions suggestive of TB. Herd confirmed positive 1998 – Michigan Department of Natural Resources bans captive deer herds in 5 county area

Michigan Bovine TB Chronology 1998 – Feeding and baiting ban on deer proposed in enforced restriction area. By 1999 this was imposed and expanded to the entire lower peninsula except for limited public viewing. Also Michigan Department of Agriculture proposes restricted movement order to control livestock moving out of this area and cervids moving in and out. Implemented in January 1999

Michigan Bovine TB Chronology new TB positive cattle herds are identified in the enforced restriction area. 3 deer outside the area ( Antrim, Osceola and Mecosta counties. MontmorencyAlpena Oscoda Alcona

Michigan Bovine TB Chronology During 2000 one cattle herd in Montmorency County and two in Alcona County were confirmed TB positive. Also, by the end of 2000, over $83 million had been committed to disease control plan implementation and in addition, the Federal Government committed $6 million to Michigan out of $60 in emergency funds for national TB eradication In June, 2000 Michigan lost its USDA TB accredited free status

Michigan Bovine TB Chronology During 2001 multiple TB positive cattle herds are identified – by May 2001, 16 positive herds had been identified in the high risk area Michigan also received Federal funds to support electronic cattle identification pilot ($1.8 million) MontmorencyAlpena Alcona Oscoda

Michigan Bovine TB Chronology In 2002 the Michigan Department of Agriculture established zones in the high-risk area to battle bovine TB Infected Zone High-Risk Area/Surveillance Zone Surveillance Zone High-Risk Area/Disease Free Zone Disease Free Buffer Zone

Michigan Bovine TB Chronology In 2002 Michigan Department of Health reported an M. bovis isolate identical to the strain circulating Michigan cattle and deer (confirmed??) from an elderly person who died of unrelated causes In 2005 another individual became infected from a cut while eviscerating a deer

Michigan Bovine TB Chronology New infected cattle herds identified in Oscoda (1) and Emmet (2) Counties Another infected cattle herd was identified in Alcona County High Risk Area/Disease Free Zone High-Risk Area/Surveillance Zone

Michigan Bovine TB Chronology Between 1995 and 2002 the Michigan Department of Agriculture had TB tested 800,000 cattle, bison and goats and 88,000 cervids 25 positive cattle herds identified I privately owned cervid herd All depopulated except two dairy herds

Michigan Bovine TB Chronology 2003 New positive cattle herds in Oscoda, Alcona, Alpena (3), and Antrim Counties The Antrim County herd became infected through purchase and legal movement of a bovine from a formerly infected herd in Presque Isle County

Michigan Bovine TB Chronology June 2004 – Federal Zone designation finalized Modified-accredited – high risk counties in Northeastern Michigan including Alcona, Alpena, Antrim, Charlevoix, Cheboygan, Crawford, Emmet, Montmorency, Oscoda, Otsego, and Presque Isle Comprehensive annual testing requirements Modified accredited advanced – remainder of Lower Peninsula Randomly selected herds tested Accredited-Free Upper Peninsula

Michigan Bovine TB Chronology As of December 31, 2003 there were 32 confirmed TB- infected cattle herds in Michigan Modifications in State zoning to address newly infected herds into 2004 July 2004 – twice-infected Montmorency dairy herd is confirmed positive 1 st positive diagnosis in 2000 followed by test and remove measures and release from quarantine in nd positive diagnosis in July /148 animals positive *3 rd positive diagnosis in 2009 – 1/224 animals positive

Michigan Bovine TB Chronology 2005 – 34 th, 35 th, and 36 th infected cattle herds are identified in Antrim(1) and Alpena (2) Counties 2006 – 37 th, 38 th. 39 th, and 40 th infected cattle herds are identified Alpena (3) Antrim (1) 2007 – 41 st, 42 nd, and 43 rd infected cattle herds are identified [Montmorency (2), Alpena(1)].

Michigan Bovine TB Chronology New Federal Zoning Order requirements for radio frequency identification devices for all cattle in all zones in Michigan and federal premises identification for all cattle herds – Modification to Zoning Order Freezer beef herds – 6 or fewer animals fed for slaughter – no breeding – are exempt from annual testing requirement

Michigan Bovine TB Chronology 2008 – 44 th and 45 th infected cattle herds are identified ( Alpena and Oscoda Counties) 2009 – Federal Zones are modified Modified accredited reduced to 5 counties Modified accredited advanced is split into sub-zones – movement determined by wildlife risk mitigation measures – without these mitigation measures, pre-movement testing is still required 2009 – 46 th infected cattle herd identified – Alpena County

Michigan Bovine TB Chronology 2010 – 47 th, 48 th, 49, and 50 th infected cattle herds are identified [Emmet (2), Alcona (1) and Alpena (1)] – 51 st and 52 nd infected cattle herds are identified (both in Alpena County) 2011 – Deer feeding and baiting ban lifted in all but four high risk Northeastern Counties 2012 – 53 rd and 54 th infected cattle herds are identified (both Alpena County)

Michigan Bovine TB Chronology 2011 – New Federal Zoning Order for Michigan Reduction in size of the Modified Accredited Zone Reduction in the Modified Accredited Advanced Zone Expansion of the TB Free Zone

Michigan Bovine TB Summary As of September infected cattle herds – 8 Herds twice-infected 45 from 4-County high risk area [Alpena (25), Alcona (13), Montmorency(4) and Oscoda (3)] 4 from Emmet County 3 from Antrim County 4752 cattle in those herds 148 with gross lesions of TB and 137 of those confirmed by culture 4 infected captive cervid herds 21 deer with gross lesions 20 were culture positive Free-ranging deer 705 positive Alpena – 199 Alcona – 255 Montmorency – 132 Oscoda – 80 Presque Isle ,061 tested

Michigan- Recent Developments April TB infected dairy herd identified in Saginaw County. This is the 56 th infected cattle herd in Michigan separated by over 100 miles and three counties from the Modified Accredited Zone

How did free ranging cervids contract this disease? 1950’s – Michigan had a lapse in cattle TB eradication efforts with a high incidence of reactors for several years in the early and mid 1950’s. Prior to 1994 only 8 cases of cervid TB had been reported nationwide. This might have been the source of Northeast Michigan’s bovine TB problem in free ranging deer

How did cervids in Michigan become a bovine TB reservoir? Bovine TB is concentrated in Michigan cervids is concentrated into a high prevalence core area where the disease appears to be self sustaining The disease does not seem to be disseminating beyond the core areas by natural deer movements. Within the core area prevalence of the disease seem to be correlated with “hot spots” of deer density Possible contributing factors: Supplemental feeding Since 1995, there have been successful attempts to reduce deer density in the core area through increased licensing for harvest and bans on supplemental feeding which should reduce disease prevalence. Efforts to reduce deer density in the core area and prevent supplemental feeding may no be sufficient to attain TB Free status in cattle in the core area Success will likely depend on deer exclusion strategies as part of on-farm biosecurity. inetb

Feeding and Baiting Feeding and Baiting of free ranging deer is banned in in Pennsylvania’s CWD Disease management areas

Feeding and Baiting The role of contaminated feed in transmission may be as significant as aerosol transmission of the disease

Bovine TB in Wildlife Reservoirs. Not restricted to the US/Michigan. Badger – United Kingdom Brush tail Possum – New Zealand Issues about control methods for these species are complex and controversial.

Is Pennsylvania Vulnerable? It is unlikely, however vigilance is important During Pennsylvania’s hunter harvest CWD surveillance any cervical lymph node with suspect pathology is submitted for histopathologic examination. Disease surveillance experts have concluded cervical lymph node examination is an excellent surveillance method as the disease is identified more frequently in cervical lymph nodes compared to thoracic viscera.

Things that keep animal health regulators awake at night Bush Meat Seizures at airports “Kane rat” aka “grasscutter” Iguana “Bushwacker” vigilance Unidentified Nigerian mammal