chengdu, China – A new study reveals continued coronavirus circulation among companion animals in Chengdu, Southwest China, one year after the peak of the COVID-19 pandemic, with a disproportionate number of infections detected in young pets. Researchers identified four distinct coronaviruses – feline coronavirus (FCoV), canine coronavirus (CCoV), crcov, and SARS-CoV-2 – in nearly 22% of sampled animals.
The findings, published [date – implied from “first postpandemic year”], underscore the ongoing risk of coronavirus spillover between animals and humans, and the critical need for sustained monitoring of these viruses in pet populations. The study,conducted on 309 samples from 263 cats and dogs,detected an overall positivity rate of 21.7% (57/263). Notably, 71.9% of positive cases (41/57) occurred in animals 12 months old or younger. This heightened vulnerability in young animals suggests a potential for rapid viral spread within pet communities.
Researchers employed a universal assay targeting the Rdrp gene,coupled with one-generation sequencing,to identify the viruses. Genetic analysis revealed dominant genotypes of FCoV-I and CCoV-IIa. Moreover, a critically important proportion of CCoV-positive dogs (72.2%, 13/18) exhibited coinfection with other viruses, most commonly canine parvovirus (CPV, 76.9%; 10/13), and, less frequently, feline parvovirus (FPV, 13.9%; 5/36).
The study also documented genetic variations within FCoV and CCoV strains circulating in the region. Specifically, researchers identified a 21-nucleotide deletion in two FCoV S genes and a 145-nucleotide deletion in one FCoV ORF3abc gene, alongside evidence of recombination events in the S* genes at positions 919 and 1639 nt. Amino acid variations in the *S genes of both FCoV and CCoV indicated regional adaptation, with FCoV strains displaying unique substitutions like Ala/Ser129Leu and a shift in the furin cleavage motif from RSRR to RARR. Chinese CCoV strains also showed significant divergence from those found in other countries.
Phylogenetic analysis revealed that the S* genes of FCoV and CCoV were closely related to prevalent strains within China, while the *S genes of CRCoV showed closer ties to human coronavirus OC43. The study included the first confirmed case of SARS-CoV-2 in a dog in mainland China, verified through viral nucleic acid detection and analysis. These findings reinforce the importance of ongoing surveillance, especially in young companion animals, to mitigate the risk of coronavirus emergence and transmission in the postpandemic era.
Keywords: codetection; companion animals; coronavirus; genetic characterizations; recombination.
