Figure 4.
H7N2 influenza in cats from 2016 New York outbreak. (A) Phylogenetic tree of influenza A viral hemagglutinin (HA) showing that feline H7N2 is closely related to avian lineages circulating in the United States. (B) Tissue culture replication of outbreak H7N2 (against comparative avian lineage) shows greater titers in mammalian cells. Virus titer (Log10PFU/mL) at hours postinfection. (C) Immunohistochemistry of nucleoprotein (NP) in sections of intranasally infected cats. Viral antigen suggests greater pervasive feline respiratory infection with outbreak H7N2 isolate. (A, Reproduced from Hatta et al. 2018, courtesy of the Centers for Disease Control and Prevention.)