1918 and 2009 H1N1 flu 'not spread by birds', finds study

Washington, Jan 20 (ANI): A new study by researchers from the Canadian Food Inspection Agency's National Centre for Foreign Animal Disease (NCFAD) and American scientists suggests that the 1918 and 2009 H1N1 flu was probably not spread by birds.

The research team injected the 2009 and 1918 H1N1 virus strains individually into chickens to come up with their findings.

It was seen that none of the birds developed flu symptoms or showed any symptoms of tissue damage up to18 days later, although nearly half the chickens developed antibodies against the 1918 H1N1 virus showing limited infection.

Also, the 1918 H1N1 virus did not lead to disease in ducks. The origin of the 1918 H1N1 virus is not known and in spite of its genetic similarity to avian influenzas, the conclusions of this study show it is almost impossible to have jumped the species barrier from chickens to humans.

Different strains of influenza cause disease in humans, birds and pigs. All viruses adapt to cause infection in their hosts. All cause almost alike respiratory symptoms. If flu viruses are passed back and forth between hosts, like close human contact with infected animals, the mixing can result in the development of a novel strain. As humans have not encountered the virus before, they have little or no immunity to a novel strain, which can easily cause infection and spread from person to person. This may eventually lead to a global flu pandemic.

"Working out how major human pandemic flu viruses affect birds and other domestic animal species is crucial in discovering what role, if any, they play in spreading viruses in the human population," lead researcher Dr Shawn Babiuk, a scientist with the National Centre for Foreign Animal Disease, said.

He added: "These findings support the use of normal veterinary management practices in poultry infected with pandemic 2009 H1N1 influenza and demonstrate that quarantining and culling infected stocks is not necessary."

The findings of the study have appeared in the February issue of the Journal of General Virology. (ANI)