Highly pathogenic avian influenza (HPAI) H5 virus exposure in domestic cats and rural stray cats, the Netherlands, October 2020 to June 2023
Background Highly pathogenic avian influenza (HPAI) H5Nx and human H1N1pdm2009 influenza viruses can infect cats. Infections in cats may result in viral adaptations or recombinant viruses, which may facilitate zoonotic transfer. Aim We aimed to investigate the presence of HPAI H5 clade 2.3.4.4 and H1 influenza viruses and antibodies to these viruses in domestic and rural stray cats in the Netherlands and factors associated with exposure. Methods Sera from stray and domestic cats, sampled 2020–2023, were analysed by ELISA and confirmed by hemagglutination inhibition assay (HAI) and pharyngeal swabs and lung tissue for influenza A virus by RT-qPCR. Results In 701 stray cats, 83 (11.8%; 95% confidence interval (CI): 9.5–14.5) sera were positive for HPAI H5 and 65 findings were confirmed. In HAI, two sera were positive for both HPAI H5 and H1. In 871 domestic cats, four (0.46%; 95% CI: 0.13–1.2) sera were HPAI H5 positive and none were confirmed but 40 (4.6%; 95% CI: 3.3–6.2) sera were ser
