Are companion animals overlooked intermediate hosts for the cross-species transmission of influenza viruses?

In 2022, a boy with influenza-like symptoms was found to be infected with a novel H3N8 avian influenza virus in Henan province (1-4). Subsequently, in May 2022 H3N8 avian influenza virus caused a second human infection in Hunan province. The H3N8 human viruses originated from chickens (3, 5), but its RNA was also detected in nasopharyngeal swabs of cats and dogs and environmental samples collected in the patient's house (4). Of note, the full-length HA sequences from pets and human patients were identical, but revealed differences to avian H3N8 suggesting adaption to mammalian hosts.