SYDNEY, NSW – SEPTEMBER 28: A sign warning of the dangers of importing avian products is displayed … More at Sydney International Airport September 28, 2005 in Sydney, Australia. (Photo by Ian Waldie/Getty Images)

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You can add one more animal to the list of mammals that the bird flu has infected.

For the first time ever, the UK has reported a case of the bird flu in a sheep. This groundbreaking development occurred on a farm in Yorkshire, England where the highly pathogenic strain of H5N1 bird flu was identified in a female sheep during routine surveillance. The farm had previously confirmed bird flu in birds, suggesting a possible mechanism for spread from birds to sheep, although this transmission route has not been confirmed. Importantly, the infected ewe was culled, and no other infections of bird flu were detected among any other animals on the farm related directly to the sheep.

Bird Flu In Humans

Since March of 2024, there have been 70 confirmed cases of bird flu in humans in the US, as well as one death confirmed in an elderly man in Louisiana who was hospitalized and had chronic medical conditions, according to the CDC. The virus has been difficult to control in birds as well as mammals including cats, dairy cows and now sheep.

As I have explained previously in Forbes, for most humans, the symptoms of bird flu are usually mild and consistent of fever, cough, sore throat, runny nose, muscle aches and fatigue. Rarely, severe symptoms can occur which can result in difficulty breathing, infection of the lung and even respiratory failure.

The virus can spread in humans in a couple ways. Most commonly, exposure occurs through direct contact with infected animals like birds and dairy cattle. Also, body fluids from infected animals like saliva and feces can cause infection if humans interact with those fluids and then touch their mouths or noses. Finally, humans can inhale small dust particles in habitats where the virus lives and then get infected.

Significance of Yorkshire Case

Bird flu now appearing in another animal is noteworthy because it means the virus has adapted and has been able to infect new hosts. Interspecies spread has previously occurred, but never to sheep. Despite the isolated case found in the sheep, the public health threat to humans remains low, according to the UK Health Security Agency.

Public Health Implications

The ability for H5N1 to infect a broader range of mammalian species raises concerns about future transmission, potentially increasing its pandemic potential. For that to occur, there would need to be increased and sustained human to human transmission, which has not occurred yet, with yet being the key word here. This could occur in the future with genetic reassortment, which is when two different strains of the virus infect a single individual and then swap some of their genetic material with each other. This could allow the virus to acquire mutations that could enhance transmissibility among humans. This has not occurred yet and the risk to humans remains low.

The Future Of Bird Flu In America

The USDA will invest one billion dollars to curb bird flu, which includes enhancing biosecurity practices, ensuring financial relief for farmers and funding vaccine and therapeutic research. However, there remains significant ambiguity on specific strategies. For example, it remains unclear if the United States will start to vaccinate dairy cattle or poultry against the bird flu, or will just provide anti-viral medications.

In addition, Robert F. Kennedy Jr., Secretary for Health and Human Services, has advocated to allow bird flu to spread through flocks to potentially induce immunity among birds and animals. Public health experts warn that this approach will not mitigate or contain the spread of bird flu, but rather call for culling and enhanced biosecurity measures to reduce bird flu transmission.

For humans, prevention should be of utmost importance. This means avoiding contact with sick animals, practicing good hygiene with handwashing, wearing personal protective equipment like gloves and goggles around livestock and avoiding contact with surfaces that could be contaminated.