Emerg Infect Dis . Seroprevalence of Influenza A(H5N1) Virus in Domestic Cats at Epicenter of Dairy Cattle Outbreaks, California, USA, 2024-2026

[tetano]

Emerg Infect Dis


. 2026 Jul 28;32(9).
doi: 10.3201/eid3209.260785. Online ahead of print.
Seroprevalence of Influenza A(H5N1) Virus in Domestic Cats at Epicenter of Dairy Cattle Outbreaks, California, USA, 2024-2026

Ian G Bemis, Ismaila Shittu, Jacob F Gomez, Esther A Fadaka, Sofia Perez, Gregory C Gray, Kristen K Coleman

• PMID: 42520787
• DOI: 10.3201/eid3209.260785

Abstract

We conducted a serologic study of domestic cats near the epicenter of the dairy cattle outbreaks of influenza A(H5N1) in California, USA. Three of the 12 cats sampled within 2 km of farms had neutralizing antibodies against H5N1 virus. Proximity to dairy farms was a statistically significant risk factor for seropositivity.

Keywords: California; H5N1; One Health; United States; avian influenza virus; cats; cross-species transmission; dairy cattle; influenza; viruses; zoonoses.

[Commonground]

(from Post #1)
Excerpts:

" One indoor-only and 1 outdoor feral cat had neutralizing antibody titers of 1:160, and 1 indoor-only cat had a titer of 1:640, indicating strong positivity and 100% agreement between the ELISA and microneutralization assay."

"All seropositive cats were in rural areas. No indoor cats were fed raw meat or dairy."

"Regarding the seropositive indoor-only cats in our study, both were from a household of a dairy industry worker, similar to the infections in Michigan cats (7). The route of transmission, including human-to-cat transmission, cannot be confirmed in our study. However, we can rule out raw meat or dairy as a potential source."