Deadly Bird Flu: New Risks of Human-Cat Transmission

A recent study released on Thursday by the U.S. Centers for Disease Control and Prevention (CDC) indicates a troubling possibility: humans may transmit avian influenza to their domestic cats, with potentially lethal outcomes.

This research, featuring two case studies from Michigan in May 2024, is documented in the agency’s Morbidity and Mortality Weekly Report. As concerns escalate regarding the virus’s possible mutation into a strain that could incite a human pandemic, the findings are particularly alarming.

It has recently been revealed that cats can also become infected through pet food tainted with the virus, and that transmission may occur among larger feline species in shelters.

In both case studies, the pet owners were associated with dairy cattle farms affected by an avian flu outbreak, resulting in the tragic deaths of the infected cats. In the first instance, a five-year-old indoor female cat exhibited a rapid decline in appetite, hygiene, disorientation, lethargy, and severe neurological deterioration.

Despite urgent care at the Michigan State University Veterinary Medical Center, her condition deteriorated rapidly, leading to euthanasia just four days later. Postmortem examinations confirmed she had indeed contracted bird flu.

Two additional cats resided in the same household; one displayed mild symptoms, which were mistakenly attributed to allergies, leading the owners to disengage from public health inquiries. Among those living in the household, a farmworker opted out of testing, while an adult and two teenagers received negative results for avian influenza.

Connection to Unpasteurized Milk

Shortly after, a separate case involving a six-month-old male Maine Coon was reported to the university. The cat showcased symptoms such as anorexia, lethargy, facial swelling, and restricted mobility, ultimately succumbing within 24 hours.

This Maine Coon lived alongside another cat that remained unaffected. The owner regularly transported unpasteurized milk from various Michigan farms, including those confirmed to harbor infected dairy cattle.

Without protective gear, the owner reported frequent direct contact with raw milk and often neglected to change contaminated clothing before returning home. Notably, the sick cat exhibited a tendency to roll in the owner’s soiled work attire, while the other cat did not.

Prior to the cat’s illness, the owner experienced eye irritation but opted against testing for avian influenza.

The CDC researchers have recommended that farmworkers take precautions by removing contaminated clothing and rinsing off any animal byproduct residues, including milk and feces, prior to entering their homes.

Since the onset of the outbreak in 2024, the U.S. has reported 69 human cases of avian influenza, though the actual number may be underreported due to insufficient testing among farmworkers. So far, one person has died.

Experts caution that with the virus circulating extensively among mammals and birds, there exists a potential risk for it to combine with seasonal influenza, conceivably mutating into a strain that facilitates efficient human-to-human transmission.

Newly appointed U.S. Health Secretary Robert F. Kennedy Jr. has expressed intentions to shift governmental focus away from infectious disease research, raising doubts about the pathogenicity of germs. Historically, he has questioned the efficacy of vaccines, deemed crucial for controlling avian influenza should it escalate to a pandemic, and has advocated for the consumption of raw milk, a known vector for the virus.

© Agence France-Presse