A real-time RT-PCR for detecting PORCINE SAPELOVIRUS (PSV)

Several cases of polioencephalomyelitis caused by Porcine sapelovirus (PSV) have been recently reported in Québec herds. Porcine sapelovirus

Several cases of polioencephalomyelitis caused by Porcine sapelovirus (PSV) have been recently reported in Québec herds.

Porcine sapelovirus (PSV) is an RNA virus in the family Picornaviridae. PSV is closely related to members of the Enterovirus genus and was previously known as porcine enterovirus 8 (PEV-8). Domestic and wild swine are the only known hosts for PSV.

PSV infection begins in the small intestine, where it replicates. The most common mode of transmission of PSV is fecal-oral. As the virus is hardy in the environment, fomites likely play a role in the transmission of the virus. PSV infections are commonly asymptomatic. PSV has been demonstrated in the feces of healthy swine, especially weaned piglets, in Brazil, Italy, Spain, Australia and USA.

Pathogenic strains of PSV have been reported in China, South Korea, United Kingdom, and USA. They can cause clinical syndromes including diarrhea, pneumonia, polioencephalomyelitis, and reproductive disorders (‘SMEDI syndrome’). The role of PSV as a pathogen, and more specifically as a cause of polioencephalomyelitis, is unclear. There is no specific data available on the morbidity and mortality of PSV infections in swine.

Polioencephalomyelitis induced by PSV mainly affects piglets 8 to 12 weeks old. Affected pigs demonstrate front and hind limb ataxia progressing to generalized weakness and lateral recumbency. Death may occur as soon as three to five days after the onset of clinical signs. Morbidity and mortality up to 20% have been reported. In USA, ISU, SDSU, KSU, and UMN diagnostic laboratories report 1 to 5 cases of PSV-induced polioencephalomyelitis every month.

Lesions seen with PSV-induced polioencephalomyelitis are consistent with other neurotropic viral infections, such as atypical porcine pestivirus (APPV), porcine enterovirus (PEV), porcine teschovirus (PTV), and porcine astrovirus type 3 (PAstV‐3). Polioencephalomyelitis is generally characterized as subacute, multifocal and non-suppurative.

Reverse transcriptase polymerase chain reaction (RT-PCR) is most commonly used to detect PSV in fecal samples and nervous tissues. Preferred samples for central nervous system (CNS) disease include the spinal cord and the brain. In situ hybridization has also been used to demonstrate the virus in the CNS.

A real-time RT-PCR for detecting PSV in fecal samples and nervous tissues is now available at Biovet.

The test is run on request.

Feel free to contact us for further information.

 

References

  1. Arruda PH, Arruda BL, Schwartz KJ, et al. Detection of a novel sapelovirus in central nervous tissue of pigs with polioencephalomyelitis in the USA. Transbound Emerg Dis. 2017 Apr;64(2):311-315.
  2. Leme RA, Silva DR, Lorenzetti E, et al. Longitudinal survey of Teschovirus A, Sapelovirus A, and Enterovirus G fecal excretion in suckling and weaned pigs. Braz J Microbiol. 2019;50(1):321-327.
  3. Li Y, Du L, Jin T, Cheng Y, et al. Characterization and epidemiological survey of porcine sapelovirus in China. Vet Microbiol. 2019; 232:13-21.
  4. Schock A, Gurrala R, Fuller H, et al. Investigation into an outbreak of encephalomyelitis caused by a neuroinvasive porcine sapelovirus in the United Kingdom. Vet Microbiol. 2014;172(3-4):381-9.