The H5N1 strain of avian flu has caused millions of bird deaths in the US and globally, posing a major threat to the poultry industry and a potential health hazard to humans, according to experts.

The virus, first identified in China in 1996, has a near 100% fatality rate among birds, killing most infected birds within 48 hours.

This year’s bird flu outbreak in the US is the worst in history and has caused a rise in poultry prices, making eggs more scarce.

The virus has also sickened people, albeit in small numbers, with a mortality rate of over 50% among humans.

Experts warn of the potential for the virus to spread from birds to humans and from humans to other humans, leading to a global influenza pandemic. The H5N1 strain has also been found in other species, including grizzlies and foxes.