Influenza A viruses (IAVs) are members of the family Orthomyxoviridae and genus Orthomyxovirus. Avian and mammalian species are the host of IAVs, which includes humans and dogs. Canine influenza virus (CIV) is an emerging pathogen that causes severe and acute respiratory diseases in dogs. This study monitored the antigen and antibody against CIV in dogs in the Republic of Korea (ROK) from 2016 to 2021. One thousand and seventy-two nasal swabs and 1,545 blood samples were collected from animal hospitals and animal shelters. Five nasal swabs in 2017 and seven in 2018 from stray dogs were positive for CIV according to RT-PCR. The prevalence of H3N2 CIV ranged from 9.5% to 24.8%, according to the hemagglutination inhibition (HI) assay. On the other hand, none of the serum samples from 2018 to 2021 showed seropositivity against the avian H5, H7, and H9 viruses. The HI titers for H3N2 ranged from 16 to 512. The distribution of HI titer 16–32 was 57.6% in seropositive samples. The pet dogs were vaccinated against CIV, but the stray and military dogs were unvaccinated. In 2017 and 2018, the seroprevalence of CIV in stray dogs was higher than in the other years, and viral RNA was detected in nasal swabs. It may mean previous exposure of stray dogs to CIV. With the increasing number of pet dogs and the close contact between humans and dogs, canines could serve as an intermediate host for transmitting IAVs to humans. Therefore, continuous surveillance of CIV is needed for public health and the potential emergence of novel zoonotic viruses.

In this study, the near-complete genome sequence of the novel reassortant H1N2 influenza A virus strain A/swine/Korea/KS60/2016 is reported. Sequences of the hemagglutinin (HA), neuraminidase (NA), and polymerase basic 2 (PB2) genes were analyzed, revealing that the isolates contain segments from previous Korean swine H1N2 strains. Additionally, the remaining genes of this strain originated from human H1N1 strains in 2009.

Influenza A virus (IAV) causes respiratory disease in birds and mammals, including pigs and humans. Infection by IAV in pigs increases not only economic losses in the swine industry but also the emergence of novel IAV variants via gene reassortment, which is important due to the susceptibility of both birds and humans to IAV. This study provides serological data obtained during a study to detect IAV infections in pigs in the Republic of Korea during 2018 and 2019. A total of 1,559 samples were collected from 74 domestic pig farms. Hemagglutination inhibition (HI) assays were performed using the A/Swine/Korea/25-13(H1N1), A/Swine/Korea/E102 (H1N2), and A/Swine/Korea/Cy10/2007 (H3N2) viruses as antigens. The HI assay results showed that 266 of the 1,559 samples were seropositive (17.0%). Among these, H1N1, H1N2, and H3N2 comprised 7.3% (114), 6.0% (93), and 8.8% (137) of the 1,559 samples, respectively. Co-infections of H1N1/H1N2, H1N1/H3N2, H1N2/H3N2 and H1N1/H1N2/H3N2 were observed in 2.1% (31), 1.5% (23), 1.5% (24), and 0.8% (13) of the 1,559 samples, respectively. Interestingly, IAV infections were detected in all nine provinces of the country.

Highly pathogenic avian influenza virus (HPAIV) damages vital organs and tissues, frequently leading to death in birds, and causes serious economic losses in the poultry industry. In addition, HPAIV can infect humans and other mammals, often with fatal outcomes. In this study, the virucidal efficacy of Clean-Zone®, which contains citric acid, malic acid and phosphoric acid, against avian influenza virus (AIV, H9N2) was investigated. Virucidal efficacy was determined by examining the viability of AIV after contact with the disinfectant in the allantoic membrane of chicken embryos. The disinfectant and AIV were reacted under hard water (HW) and organic matter suspension (OM) condition. AIV was inactivated with 200- and 50-fold dilutions of the disinfectant under HW and OM conditions, respectively. As the disinfectant, Clean-Zone®, has a virucidal efficacy against AIV, it can be used to prevent the spread of animal viral diseases.

In this study, the virucidal efficacy of a fumigant (35% paraformaldehyde) against avian influenza virus (AIV) was examined. After AIV suspensions had been deposited on stainless steel carriers, the dried carriers were exposed to the fumigant in a 300-m3 test room for 3 h. Thereafter, all carriers were submerged in a neutralizing solution to scrape off the surviving viruses, and the respective suspensions were diluted. Each dilution factor was respectively inoculated into the allantoic membrane of five 10-day-old embryos. After incubation, AIV viability in the collected allantoic fluids was examined and the EID50 was calculated. The fumigant inactivated ≥5.7log10EID50 of AIV and was nontoxic to the embryos.