Aujeszky

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Aujeszkys Disease

• Pseudorabies, Mad Itch

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Overview

• Organism
• Economic Impact
• Epidemiology
• Transmission
• Clinical Signs
• Diagnosis and Treatment
• Prevention and Control
• Actions to Take

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The Organism
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Aujeszkys Disease

• Alphaherpesvirus
• Genus Varicellovirus
• Highly contagious
• Natural hosts
• Domestic and feral swine
• Attenuated strain in feral swine
• Somewhat persistent in environment
• Several days in environment
• Aerosol (under favorable conditions)

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Importance
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History

• 1902
• Aládar Aujeszky, Hungary
• First identified in cattle and dogs
• Determined swine werenatural hosts
• 1931 mad itch same asAujeszkys disease
• 1983 survey
• 18.8 U.S. breeding swine

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History in the U.S.

• 1989
• National eradication program
• USDA APHIS, States and producers
• Over 8000 herds identified
• 1992
• Over 1000 herds remain
• 2004
• U.S. commercial swine herds pseudorabies free

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Economic Impact

• Trade restrictions
• 1988 study U.S. epizootic
• Newborn pig mortality
• 76.5 of total net losses (TNL)
• Estimated 24/inventoried sow/week
• Nursery pig mortality (12.6 TNL)
• Sow culling and deaths (9.4 TNL)
• Hogs and Pigs, U.S., 2008
• 3 million head farrowed
• 28.1 million pig crop

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Epidemiology
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Geographic Distribution
Disease Distribution from January to June, 2007
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Pseudorabies Stages in U.S.
As of Feb 2008
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Morbidity/Mortality

• Morbidity
• Up to 100 in domestic pig herds
• Up to 20 abortions
• Feral swine do notdevelop signs of disease
• Mortality
• Highest for younger animals
• Up to 100 - newborn piglets
• Up to 50 - nursery pigs
• Decreases with age
• 5-10 in weaner pigs
• 1-2 in grower/finisher pigs
• Always fatal in other animal species

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Transmission
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Transmission Pigs

• Direct Contact
• Nose-to-nose contact
• Reproductive
• Venereal and transplacental
• Ingestion
• Aerosol
• At least 55 relative humidity
• Persists up to 7 hours
• Can travel up to 2 km
• Fomites
• Contaminated bedding and water
• Meat products or carcasses

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Transmission Other species

• Contact with infected pigs
• Ingestion of infected meat
• Rarely lateral transmission

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Animals andAujeszkys Disease
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Clinical Signs Pigs

• Incubation period 2-6 days
• Piglets less than 1 week old
• Fever, listlessness, anorexia
• Neurological
• Tremors, paddling, seizures,
• Hind leg paralysis - dog-like position
• High mortality within 24-36 hours
• Slightly older piglets
• Similar signs, lower mortality
• Vomiting and respiratory signs

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Clinical Signs

• Weaned pigs
• Respiratory illness
• Neurological signs
• Recover in 5-10 days
• Adult pigs
• Mild or inapparent infection
• Respiratory neurological signs
• Pregnant sows reproductive problems
• Feral swine
• Asymptomatic

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Clinical Signs Other Animals

• Cattle and sheep
• Intense pruritus
• Licking, rubbing, gnawing, self-mutilation
• Neurological signs
• Dogs and Cats
• Similar to cattle and sheep
• Pharyngeal paralysis and profuse salivation
• Resembles rabies
• Death in a few days

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Post Mortem Lesions

• Serous or fibrinonecrotic rhinitis
• Visible if head split and nasal cavity opened
• Pulmonary edema, congestion, consolidation
• Secondary bacterial pneumonia
• Congested and hemorrhagic lymph nodes
• Necrosis

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Post Mortem Lesions Pigs

• Neurological
• Nonsuppurative meningoencephalitis
• Mononuclear perivascular cuffing
• Neuronal necrosis
• Thickened meninges
• Respiratory
• Necrotic tonsillitis, bronchitis, bronchiolitis,
  alveolitis
• Reproductive (fetus)
• Focal necrosis of liver, spleen, adrenal glands,
  lymph nodes

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Post Mortem Other Species

• Edema, congestion, and hemorrhage in the portions
  of the spinal cord that innervate the areas of
  pruritus
• Cellular infiltration and neuronal degeneration

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Differential Diagnosis

• Pigs
• Porcine polioencephalomyelitis
• Classical or African swine fever
• Hemagglutinating encephalomyelitis infection
• Streptococcal meningoencephalitis
• Swine influenza
• Erysipelas
• Nipah virus infection
• Salt or organic poisoning
• Species other than pigs
• Rabies
• Scrapie in sheep

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Diagnosis Laboratory

• Clinical signs suggestive
• Virus isolation
• Detection of viral DNA or antigens
• Immunofluorescence, immunoperoxidase, virus
  neutralization assays, PCR
• Serology
• Virus neutralization, latex agglutination, ELISAs

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Aujeszkys Diseasein Humans

• Disease has not been reported in humans

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Prevention and Control
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Recommended Actions

• Notification of Authorities
• Federal
• Area Veterinarian in Charge (AVIC)
  www.aphis.usda.gov/animal_health/area_offices/
• State veterinarian www.aphis.usda.gov/vs/sregs/off
  icial.htm
• Quarantine

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Quarantine and Disinfection

• Isolate and test
• New breeding animals
• Biosecurity measures
• Prevent entry
• By fomites, people,roaming animals
• Double fencing
• Disinfection
• Phenols and quarternary ammonium compounds,
  sunlight, drying, high temps

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Quarantine and Disinfection

• Depopulation and repopulation
• Premises cleaned, disinfected
• Left empty for 30 days
• Test and removal
• Test breeding herd monthly
• Remove positive animals
• Difficult to detect the latently infected
• Offspring segregation
• Vaccinate breeding herd
• Remove young weaned pigs

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Vaccination

• Protects pigs from clinical signs
• Decrease virus shedding
• Does not provide sterile immunity or prevent
  latent infections
• Attenuated, inactivated, gene-deleted vaccines
• Vaccinated pigs which become infected can be
  detected

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Additional Resources

• USDA-APHIS website
• www.aphis.usda.gov
• World Organization for Animal Health (OIE)
  website
• www.oie.int
• Center for Food Security and Public Health
• www.cfsph.iastate.edu/DiseaseInfo/
• Food and Agriculture Organization of the United
  Nations (FAO) website
• www.fao.org

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Acknowledgments

• Development of this presentationwas funded by
  grants from
• the Centers for Disease Control and Prevention,
  the Iowa Homeland Security and Emergency
  Management Division, and the Iowa Department of
  Agriculture and Land Stewardship to the Center
  for Food Security and Public Health at Iowa State
  University.
• Authors Katie Spaulding, BS Anna Rovid
  Spickler, DVM, PhD Reviewers James Roth, DVM,
  PhD Glenda Dvorak, DVM, MPH, DACVPM