This document summarizes information about Porcine Reproductive and Respiratory Syndrome Virus (PRRSV). PRRSV is an enveloped, positive-sense, single-stranded RNA virus that infects domestic pigs. It causes respiratory disease in piglets and reproductive failure in sows, resulting in increased pre-weaning mortality and fewer viable piglets born. The virus spreads between pigs through respiratory and bodily secretions. Diagnosis involves PCR or serological testing of samples like blood, tissues, and nasal swabs. Vaccination with live attenuated or inactivated vaccines can help prevent disease, as can testing, isolation, improved hygiene, and limiting introduction of new pigs.

2. •Derived from Equine Areteritis virus

3. •Spherical virions
•50-70 nm in diameter
•Enveloped
•Linear positive sense
•Single-stranded RNA
•13-15 kb in size
•Infectious genomic RNA

4. •Single
nucleocapsid
protein-N
• 6 enveloped
proteinsE,GP2,GP3,GP
4
GP5,M

5. •Large enveloped
gycoprotein

7. Order: Nidovirales
Family: Arteriviridae
Genus: Arterivirus
Species: Equine Arterivirus
Lactate Dehydrogenase
Elevating
virus
Porcine Reproductive and
Respiratory Syndrome Virus

8. •Replicate mostly in macrophages
•Very minimal in other cell types
•Host range is highly restricted
•Can subvert protective host innate
immune responses
•Apoptosis
•IFN signaling pathways

9. •Receptors for PRRS
1. CD163
2.Sialoadhesin
3. Heparin Sulfate
Glycosaminoglycans

10. CYTOPLASMIC
•Attachment to host
receptors mediates
clathrin-mediated
endocytosis of the
virus into the host
cell.

11. •Fusion of virus
membrane with the
endosomal
membrane.
•ssRNA(+) genome
is released into the
cytoplasm.

12. •Synthesis and
proteolysis of
replicase
polyproteins.
•Replication occurs
in viral factories.
•A dsRNA genome is
synthesized from the
genomic ssRNA(+).

13. •dsRNA
genome
is
transcribed
thereby
proiding
ssRNA(+) genomes.
•Synthesis
of
structural
proteins
encoded
by
subgenomic
mRNAs.

14. •Assembly and buddi
ng at the membranes
of ER, intermediate
compartments,
and/or
Golgi
complex.
•Release
of
new
virions.

15. 1. Equine Viral Arteritis
2. Porcine Reproductie and
Respiratory Syndrome
3. Lactate Dehydrogenase Elevating
Disease
4. Simian Hemorrhagic Fever

16. PINK EYE

17. SCROTAL EDEMA

19. •1st designated as “mystery swine
disease”
•“lelystad virus”-Netherland
•Causative virus first appeared-US,
Asia, Europe

20. •Infects only domestic and wild pigs
•initially characterized by
•Anorexia
•Fever
•Lethargy

21. •Affected animals:
•Dyspnea/ hyperpnea
•Transient hyperemia
•Cyanosis of the extremities

23. Dry sows-first month of infection
•Short periods of inappetence
•The body temperature may be
elevated

24. •Transient discoloration (blueing) of the
ears
•Premature births

25. •Sows in late gestation
•Abortion
•Premature births
•Stillbirths
•Mummified fetuses

27. stillbirth
Mummified fetuses

28. •More diarrhoea.
•Less viable piglets.
•Increase in respiratory infections

29. Diarrhea in infected
piglets

30. •Period of slight inappetence.
•Mild coughing.
•Hairy wasting pigs.
•In some herds there are no symptoms.

31. weakness
Rough hair coat

32. •Inappetence
•Increased body temperature
•Lethargy
•Loss of libido
•Lowered fertility
•Poor litter sizes
•Lowered sperm output

33. •Droplet contamination
•Nasal secretions, saliva, feces and
urine
•Permanently populated houses
•Movement of carrier pigs.

34. •Airborne transmission
•Mechanical means via faeces, dust,
droplets and contaminated equipment,
etc.
•Contaminated boots and clothing.
•Vehicles.
•Artificial insemination

35. •Mortality is high
•Direct contact
•Through secretions
•Excretions
•Transplacental transmission

36. PATHOGENESIS
• virus replicates in the macrophages
of the lungs, lymphoid tissue and
endothelial cells
•Viremia-24 hours

37. Lesions of acute infection
•Lymph node enlargement
•Intestinal pneumonia

38. DISEAS CAUSATI
ES
VE
AGENT
SAMPLE/S
DIAGNOSTIC
TEST
NASOPHARYNGEAL
SWABS, BLOOD
RT-PCR
EQUINE
VIRAL
ARTERITIS
EQUINE
ARTERIVIRUS
PORCINE
REPRODUCT
IE AND
RESPIRATO
RY
SYNDROME
PORCINE
REPRODUCTIE
AND
RESPIRATORY
SYNDROME
VIRUS
TISSUES
LACTATE
DEHYDROGE
GENASE
ELEVATNG
DISEASE
LACTATE
DEHYDROGENA
SE ELEVATNG
VIRUS
BLOOD
SEROLOGICAL
EXAMINATION
SIMIAN
SIMIAN
WHOLE BLOOD
REVERSE
PLACENTAL TISSUES AND
FLUIDS FROM FETAL LUNG,
LIVER,
LYMPHORECTICULAR
TISSUES
IMMUNOHISTOCHEMICAL
TESTING
HISTOCHEMICAL
STAINING
BLOOD
SEROLOGICAL
EXAMINATION

39. •Infected pigs are immune to reinfection
•Vaccination-live attenuated, inactivated
•limit the frequency of seed stock
introductions to the sow herd
•assure that the replacement gilts be
well-acclimatized to the PRRS virus

40. •Boars introduced into negative herds
should be quarantined for 60-90 days
after purchase and confirmed negative
serologically

41. •depopulate, clean and disinfect the
facilities and, after a few weeks,
repopulate with stock free of PRRS

42. •Control is by exclusion
•no specific treatment
•Broad-spectrum antibiotics.
•Anti-inflammatory products (e.g.
aspirin)

43. • Other helpful techniques
• Early weaning and isolation of piglets
•Regular serologic monitoring
• Testing (ELISA, PCR and IFA)
•Removal of persistent carriers in herds
•improving biosecurity.