H9N2 influenza A virus (IAV) causes low pathogenic respiratory disease and infects a wide range of hosts. In this study, six IAVs were isolated from mink and identified as H9N2 IAV. Sequence analysis revealed that the six isolates continued to evolve, and their PB2 genes shared high nucleotide sequence identity with H7N9 IAV. The six isolates contained an amino acid motif PSRSSR↓GL at the hemagglutinin cleavage site, which is a characteristic of low pathogenic influenza viruses. A serosurvey demonstrated that H9N2 IAV had spread widely in mink and was prevalent in foxes and raccoon dogs. Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts. Virological and epidemiological surveillance of H9N2 IAV should be strengthened for the fur animal industry.
Disease Transmission, InfectiousAmino Acid MotifsAnimalsAntibodies, ViralFoxesInfluenza A Virus, H9N2 SubtypeMinkOrthomyxoviridae InfectionsRaccoonsRNA-Dependent RNA PolymeraseSequence Analysis, DNASeroepidemiologic StudiesViral ProteinsPB2 protein, Influenzavirus A
Structured evidence records
Evidence records
12 total
Host Range Experiment3 records
Host Range ExperimentExtraction confidence 0.95
Key finding
Mink-derived H9N2 influenza A virus was experimentally shown to transmit to and infect mink, foxes, and raccoon dogs under close-contact and challenge conditions.
Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts.
Method
transmission experiment; challenge study
Experimental system
in vivo animal experiment
Host Range ExperimentExtraction confidence 0.95
Key finding
Mink-derived H9N2 influenza A virus infected foxes in experimental challenge and close-contact transmission assays.
Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts.
Method
transmission experiment; challenge study
Experimental system
in vivo animal experiment
Host Range ExperimentExtraction confidence 0.95
Key finding
Mink-derived H9N2 influenza A virus infected raccoon dogs in experimental challenge and close-contact transmission assays.
Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts.
Method
transmission experiment; challenge study
Experimental system
in vivo animal experiment
Serological Evidence3 records
Serological EvidenceExtraction confidence 0.90
Key finding
Serosurvey results showed widespread H9N2 influenza A virus exposure in mink and antibody prevalence in foxes and raccoon dogs.
A serosurvey demonstrated that H9N2 IAV had spread widely in mink and was prevalent in foxes and raccoon dogs.
Method
serosurvey; Seroepidemiologic Studies
Sample type
blood; serum
Cross Species Transmission2 records
Cross Species TransmissionExtraction confidence 0.98
Key finding
Mink-derived H9N2 influenza virus was transmitted from infected mink to foxes and raccoon dogs through close contact, confirming interspecies virus spread among fur animals.
Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals.
Method
transmission experiment
Study design
animal experiment
Transmission direction
animal-to-animal
Cross Species TransmissionExtraction confidence 0.98
Key finding
Mink-derived H9N2 influenza virus was transmitted from infected mink to raccoon dogs through close contact, demonstrating interspecies viral transmission among carnivores.
Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals.
Method
transmission experiment
Study design
animal experiment
Transmission direction
animal-to-animal
Genomic Evolution1 records
Genomic EvolutionExtraction confidence 0.75
Key finding
H9N2 influenza A viruses isolated from mink showed continued evolution and PB2 gene similarity to H7N9 viruses, indicating genomic relatedness and ongoing evolution.
Naturally occurring Influenza A virus subtype H1N2 infection in a Midwest United States mink (Mustela vison) ranch. Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 2012;24:388–391
Full genome comparison and characterization of avian H10 viruses with different pathogenicity in Mink (Mustela vison) reveals genetic and functional differences in the non-structural gene
Phylogenetic analysis of eight genes of H9N2 subtype influenza virus: a mainland China strain possessing early isolates’ genes that have been circulating
Evidence of avian-like H9N2 influenza A virus among dogs in Guangxi, China. Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases. 2013;20:471–475
Construction of a recombinant duck enteritis virus vaccine expressing hemagglutinin of H9N2 avian influenza virus and evaluation of its efficacy in ducks
