Cats as sentinels of H5Nx exposure: A seroprevalence study, France (2023–2025)
Highly pathogenic avian influenza viruses (HPAIV) H5Nx, notably clade 2.3.4.4b, have been increasingly circulating among avian populations and have been detected in mammals, including domestic cats. Given their role in bridging domestic environments and wildlife, cats serve as potential sentinels for assessing exposure to HPAIV. A recent study aimed to evaluate the seroprevalence of these viruses among outdoor cats in France over a 14-month period, investigating risk factors such as geographic location and hunting behavior.
The study included 728 cats (642 domestic and 86 stray) sampled from 44 veterinary practices across France. Using an anti-H5 ELISA kit, researchers analyzed serum samples for antibodies against HPAIV H5Nx. The estimated seroprevalence of H5Nx avian influenza viruses in cats in France was 2.6%, indicating significant exposure to these viruses. Hunting behavior was a key risk factor, with non-hunting owned cats exhibiting lower odds of seropositivity compared to stray cats. The findings underscore the exposure of the feline population to H5Nx avian influenza viruses, with the majority of cases linked to the H5N1 subtype.
