23. Aujeszky’s disease (diagnosis, prevention, control, eradication).

Question 1

Diagnosis?

Answer 1

Diagnosis:

• history, clinical signs, virus isolation
• (nasal discharge, brain, lung - CPE within 1-2 days),
• from tissue (IF, IP, latent infections PCR, NS hybridization),
• serology (VN, ELISA - discriminative, CF, AGID)

Question 2

Differential diagnosis?

Answer 2

Differential diagnosis:

1. every CNS signs diseases,
2. Teschen disease,
3. classical swine fever

Question 3

Prevention?

Answer 3

Prevention:

• reduce mixing animals,
• separation of swine from other species,
• don’t feed carnivores with raw pork and organs, immunization
• Immunization: IgE negative marker vaccines, attenuated/inactivated, protection from 7-10 days
• until 3-4 months
• Basic immunization with attenuated live virus
• 1st vaccination of maternally protected pigs on 10-12 weeks and repeat in 2 weeks
• Gilts: vaccinations at the age of 6 months, at fertilization and at 70-90th day of pregnancy
• Ruminants, carnivores: vaccine not reliable (attenuated can cause disease, inactivated will
• not protect longterm)

Question 4

Eradication?

Answer 4

Eradication:

• The virus can maintain in vaccinate pigs
• Obligatory eradication ʹ national laws
• Replacement ʹ (UK, Denmark) ʹ expensive
• Raising virus-free generation: early weaning of pigs from vaccinated sows, isolated keeping,
• serological testing
• Selection with the help of marker vaccines
• Immunisation of the whole herd with marker vaccine in every 4months
• Regular checking with discriminative ELISA
• Isolation ofthe different age-groups reduced virus shedding,slower spread
• When the number of sero-positives are low, their removal from the herd
• “Vaccinated virus free “animals serological monitoring (10%inevery 6months)+
• testing of abortions, stillbirths
• Ceasing vaccination ʹ becoming seronegative
• Maintenance of the virus-free status
• Epizootiological measures, import from free herds, quarantine
• Regular serological monitoring (ELISA)