Continuing Diagnostic Investigation–Novel Sapelovirus - Dr. Paulo Arruda, from the 2016 Allen D. Leman Swine Conference, September 17-20, 2016, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2016-leman-swine-conference-material

1. Detection of a Novel Sapelovirus in
Central Nervous Tissue of Pigs with
Polioencephalomyelitis in the U.S.
Paulo H.E. Arruda, Bailey L. Arruda, Jerome Nietfeld, Fabio
Vannucci, Talita Resende, Albert Rovira, Paul Sundberg,
Kent J. Schwartz, Ben M. Hause

2. History
• 3,000 finishing swine operation
• 11-week-old pigs
– All affected animals originated from a single
nursery and were placed in two different finishers
at 9 weeks-of-age
• Atypical neurologic disease
• Morbidity of 20%
• Case fatality rate of 30%

4. Clinical Signs
• Inappetence, compromised ambulation, ataxia,
incoordination, mental dullness, paresis,
paralysis and decreased response to
environmental stimuli
• http://www.swinehealth.org/sapelovirus/

5. Submission
• First case – brain, lung and lymph node
• Second case – brain, heart, lung, kidney, liver,
spleen, lymph node and spinal cord (3 animals
were sampled)
• Tests were performed individually

8. Diagnostic Results
• No significant bacteria was isolated
• PCR negative for Enterovirus and Teschovirus
• PRRS*, pseudorabies, porcine pestivirus and
circovirus PCR negative
• Immunohistochemistry for PRRSV, PCV2 and
Listeria - negative
• Sapelovirus detected by PCR

10. Additional Diagnostics

11. Next-Generation Sequencing
1. Confirmation of Sapelovirus PCR
results
• Genome sequence of the virus
2. Identification of other potential
known pathogens
3. Potential discovery of a novel
pathogen

12. Sapelovirus A strain KS05151 (AIE77643)
Sapelovirus A strain KS04105 (AIE77642)
Sapelovirus A strain csh (AEK31168)
Sapelovirus A strain YC2011 (AFR77081)
Sapelovirus A strain JD2011 (AHA61456)
Sapelovirus A strain QT2013 (AHY20040)
Sapelovirus A strain KS055217 (AIE77644)
Sapelovirus A strain USA/IA33375/2015 (KX574284)
Sapelovirus A strain ISU-SHIC (KX810827)
Sapelovirus A strain V13 (AF406813)
Sapelovirus B strain SV2-2383 (AY064708)
Avian Sapelovirus strain TW90A (AY563023)
99
99
87
90
82
0.2
The VP1 amino acid sequence of members of the genus Sapelovirus were aligned by
ClustalW and phylogeny was inferred by Maximum Likelihood analysis with using the
best fitting LG+G substitution model with branching strength evaluated by 1,000
bootstrap replicates.

13. Protein Length (a.a.)
Identity to other
Porcine Sapeloviruses
(%)
L 84 94.1-97.6
VP4 53 88.7-96.2
VP2 238 92.4-95.4
VP3 234 86.3-91.5
VP1 285 84.6-87.0
2A 226 86.7-96.5
2B 105 97.1-100
2C 332 92.8-94.6
3A 100 89.0-90.0
3B 22 86.4-95.5
3C 182 96.7-98.9
3D 462 94.8-98.3
Predicted proteins encoded by Sapelovirus A strain ISU-SHIC
and their identity to other Sapelovirus A strains.

14. PSV in situ hybridization. A. PSV mRNA encoding VP1 protein was demonstrated
predominantly in the nerve roots of the spinal cords of affected animals (presumably
Schwann cells). B. Neuron with intracytoplasmic positive staining. Figure on right corner
shows a higher magnification of cell with positive staining. Hybridization signal: red.
Counterstaining: Mayer's Hematoxylin.

15. Conclusions and Future Studies
• Novel sapelovirus (genetically divergent) was the only
pathogen detected in association with a unique clinical
presentation and severe polioencephalomyelitis
• Virus was demonstrated within lesions by in situ
hybridization
• Neurologic disease has not been reported to be
associated with sapelovirus from other animal species in
the US

16. Conclusion and Future Studies
• Virus isolation in cell culture
• Development of an animal model and reproduction of
disease
– Pathogenesis
– Virus distribution
• Other potential clinical signs (subclinical, respiratory or
enteric disease, immunosuppression, reproductive)
• Prevalence/ecology/epidemiology
• Genetic diversity of viruses circulating in the US
• Prevention/treatment

17. Thanks

18. Thank you
Field veterinarian
• “Listen to your patient, he is telling you
the diagnosis” William Osler