In December 2016, a low pathogenic avian influenza (LPAI) A(H7N2) virus was identified as the causative source of an outbreak in a cat shelter in New York City, which subsequently spread to multiple shelters in New York and Pennsylvania. One person with occupational exposure to infected cats became infected with the virus, representing the first LPAI H7N2 human infection in North America since 2003. Considering the close contact that frequently occurs between companion animals and humans, it was critical to assess the relative risk of this novel virus to public health. Virus isolated from the human case, A/New York/108/2016 (NY/108), caused mild and transient illness in ferrets and mice, but did not transmit to na?ve co-housed ferrets following traditional or aerosol-based inoculation methods. Environmental persistence of NY/108 virus was generally comparable to other LPAI H7N2 viruses. However, NY/108 virus replicated with increased efficiency in human bronchial epithelial cells compared with previously isolated H7N2 viruses. Furthermore, the novel H7N2 virus was found to utilize a relatively lower pH for HA activation, similar to human influenza viruses. Our data suggest that the LPAI H7N2 virus requires further adaptation before representing a substantial threat to public health. However, the reemergence of a LPAI H7N2 virus in the Northeastern United States underscores the need for continuous surveillance of emerging zoonotic influenza viruses, inclusive of mammalian species such as domestic felines that are not commonly considered intermediate hosts for avian influenza viruses.

IMPORTANCE Avian influenza viruses are capable of crossing the species barrier to infect mammals, an event of public health concern due to the potential acquisition of a pandemic phenotype. In December 2016, an H7N2 virus caused an outbreak in cats in multiple New York animal shelters, which was the first detection of this virus in the Northeastern U.S. in over a decade and the first documented infection of H7N2 virus in a felid. A veterinarian became infected following occupational exposure to H7N2 virus-infected cats, necessitating the evaluation of this virus for its capacity to cause mammalian disease. While the H7N2 virus was associated with mild illness in mice and ferrets, and did not spread well between ferrets, it nonetheless possessed several markers of mammalian virulence. These data highlight the promiscuity of influenza viruses and the need for diligent surveillance across multiple species to quickly identify an emerging strain with pandemic potential.