Scientists studying the response to mild and severe avian influenza strains in different species have found that immune processes and key genes play a crucial role in how species respond to infection.
A research team from The Roslin Institute, Edinburgh, attempted to identify the biological differences between a range of bird species that influence the outcome of infection. A wide range of bird species were infected with the severe avian influenza strain. The results showed:
Pigeons had low levels of the virus in their bodies and showed a low immune response after being exposed to avian influenza infection, suggesting that they have an inherent ability to prevent viruses from entering cells or spreading – making them highly resistant to the disease.
The researchers also believe they have demonstrated that pigeons have a built-in protection by having high levels of what are known as interferon-stimulated genes. These genes are important in how humans and animals respond to infections.
Interferons are a group of various proteins that act as signaling substances between cells and that increase the body's resistance to viral infections. Together, they are highly effective in resisting and controlling pathogens – the microorganisms that cause infections.
It is largely in flocks of birds that are raised for slaughter and consumption, or otherwise included in human flocks, that the most serious cases are found. When many birds are crowded together under unnatural conditions, the possibilities for infection are obviously great.
“Why do pigeons get such bad publicity? Why are pigeons considered to be full of diseases that will kill you if you so much as come near one? Unfortunately, the answer is: greed! "Pest control companies view pigeons as an endless source of income (because control methods are extremely ineffective in the long run) and they spread misinformation and exaggerate everything - thereby making people anxious and unempathetic about pigeons."
The three centers The Center for Disease Control in Atlanta, the New York City Department of Health, and the Arizona Department of Health everyone agrees that diseases associated with pigeons represent little or no risk to humans. "We have never documented a pigeon to human infection in the state of Arizona" says Mira J. Leslie, Arizona state veterinarian specializing in public health.
Dr. David A Palmer (BVSc., MRCVS) stated in an article entitled 'Pigeon Lung Disease Fatality and Health Risk from Ferals': “It is clear that if one has a compromised immune system, e.g. in the form of a specific allergy or a lung disease that causes breathing difficulties, then one will react to anything that may be irritating to the bronchi and lungs. But it is really absolute nonsense for a popular daily newspaper to claim that pigeons pose a health hazard and probably need to be removed for the nation's health. ”
Mike Everett, spokesman for the Royal Society for the Protection of Birds in England stated in 'The Big Issue Magazine', February 2001: 'This whole' rats with wings' thing is once emotional nonsense. There is none evidence that they (pigeons) spread disease. ”
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