Epidemiological Milestone: First Documented Cat-to-Human H5N1 Bird Flu Transmission
In a significant development for avian influenza epidemiology, a CDC-led investigation has documented the first-ever serologic evidence of highly pathogenic avian influenza A(H5N1) transmission from a domestic cat to a human. This landmark case involved an asymptomatic veterinary professional in Los Angeles County, California.
The transmission occurred after the veterinary professional was exposed to a domestic cat infected with H5N1. Investigators believe the cat contracted the virus after consuming raw milk, raw meat, or raw animal-derived pet food products.
To evaluate the extent of the transmission, public health officials conducted serologic testing on 25 individuals who had been exposed to the infected cat. Out of these, one veterinary professional returned antibodies consistent with prior H5N1 infection.
Public Health Implications & Recommendations
While the CDC emphasizes that the overall risk of H5N1 to the general public remains low and there is currently no evidence of sustained human-to-human transmission, this case highlights a novel vector of infection.
- Raw Feed Warnings: Public health and veterinary officials continue to strongly advise against feeding domestic cats raw milk, raw meat, or raw animal-based pet food products, which have been frequently implicated in feline H5N1 infections.
- Veterinary PPE: The CDC and veterinary associations recommend that veterinary professionals and clinic staff wear appropriate Personal Protective Equipment (PPE) when handling or managing suspected or confirmed avian influenza cases in domestic pets.