Mammalian orthoreovirus impacts pigs and cattle and causes fever, diarrhea and nasal discharge
15 July 2025
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Editor’s observe: The next is from a presentation by W. Ma and colleagues on the College of Missouri and Kansas State College through the 2024 North American PRRS Symposium.
Mammalian orthoreovirus (MRV) infects a number of mammalian species together with people. A US Midwest swine farm with roughly 1,000 3-month-old pigs skilled an occasion, during which greater than 300 pigs confirmed neurological indicators, like “down and peddling”, with roughly 40% mortality. A novel MRV was remoted from the diseased pigs.
Sequence and phylogenetic evaluation revealed that the isolate was a reassortant virus containing viral gene segments from three MRV serotypes that infect people, bovines and swine. The M2 and S1 phase of the isolate confirmed 94% and 92% nucleotide similarity to the M2 of the MRV2 D5/Jones and the S1 of the MRV1 C/Bovine/Indiana/MRV00304/2014, respectively; the remaining eight segments displayed 93%–95% nucleotide similarity to these of the MRV3 FS-03/Porcine/USA/2014.
Pig research confirmed that each MRV-infected and native contact pigs displayed fever, diarrhea and nasal discharge. MRV RNA was detected in numerous intestinal areas of each contaminated and make contact with pigs, indicating that the MRV isolate is pathogenic and transmissible in pigs. Seroconversion was additionally noticed in experimentally contaminated pigs.
A prevalence examine on greater than 180 swine serum samples collected from two states with out the illness revealed 40%–52% positives to MRV. All outcomes warrant the need to watch MRV epidemiology and reassortment because the MRV might be an necessary pathogen for the swine trade and a novel MRV would possibly emerge to threaten animal and public well being.
