First report and genetic characterization of Seneca Valley virus (SVV) in Chile

Abstract

Seneca Valley virus (SVV) is a non‐enveloped RNA virus and the only member of the Senecavirus A (SVA) species, in the Senecavirus genus, Picornaviridae family. SVV infection causes vesicular lesions in the oral cavity, snout and hooves of pigs. This infection is clinically indistinguishable from trade‐restrictions‐related diseases such as foot‐and‐mouth disease. Other clinical manifestations include diarrhoea, anorexia, lethargy, neurological signs and mortality in piglets during their first week of age. Before this study, Chile was considered free of vesicular diseases of swine, including SVV. In April 2022, a suspected case of vesicular disease in a swine farm was reported in Chile. The SVV was confirmed and other vesicular diseases were ruled out. An epidemiological investigation and phylogenetic analyses were performed to identify the origin and extent of the outbreak. Three hundred ninety‐five samples from 44 swine farms were collected, including faeces (208), oral fluid (28), processing fluid (14), fresh semen (61), environmental samples (80) and tissue from lesions (4) for real‐time RT‐PCR detection. Until June 2022, the SVV has been detected in 16 out of 44 farms, all epidemiologically related to the index farm. The closest phylogenetic relationship of the Chilean SVV strain is with viruses collected from swine in California in 2017. The direct cause of the SVV introduction has not yet been identified; however, the phylogenetic analyses suggest the USA as the most likely source. Since the virus remains active in the environment, transmission by fomites such as contaminated feed cannot be discarded. Further studies are needed to determine the risk of the introduction of novel SVV and other transboundary swine pathogens to Chile.

Novel introductions of human-origin H3N2 Influenza viruses in Swine, Chile

“…Comprehensive sequencing requires specialized equipment, expertise, and resources; therefore, it is crucial to prioritize sequencing cases with unusual clinical presentations or characteristics that may indicate new viral introductions. As a surveillance enhancement alternative, Oxford Nanopore technologies have emerged, providing increased sequencing capabilities at a more economical cost and faster (14,27,28).…”

First detection and genetic characterization of Senecavirus A in pigs from Mexico

“…Since late 2014, a global increase in the occurrence of SVA infection cases in the United States, Brazil, Colombia, China, Thailand, Vietnam, and Chile has been reported. [11][12][13][14][15][16] Phylogenetic analyses has shown the evolutionary divergence between SVA historical and contemporary strains and most SVA strains are grouped in separate phylogenetic clusters based on their geographic location.…”

“…15 Recently, SVA was confirmed to be the cause of vesicular disease in swine from Chile, allegedly originating from SVA strains circulating in the United States. 16 In Mexico, SVA is considered an exotic virus by the National Secretary of Agriculture and Rural Development; thus, disease caused by SVA mandates immediate notification to the National System of Epidemiological Surveillance. 17 No official information or scientific reports of SVA in the swine population within the Mexican national territory have been previously reported.…”

RNA recombination: non-negligible factor for preventing emergence or reemergence of Senecavirus A

“…A retrospective study unexpectedly exhibited that SVA was circulating in the pig population of the United States as early as 1988, or even earlier ( 6 ). To date, SVA has been found in several countries, including Canada ( 4 ), the United States ( 7 ), Brazil ( 8 ), China ( 9 ), Thailand ( 10 ), Vietnam ( 11 ) and more recently Chile ( 12 ), therefore attracting a great deal of attention from the pig industry worldwide.…”