How Does Bird Flu Spread?

How Does Bird Flu Spread?

Migrating birds, like ducks, geese, and swans, can carry and spread the virus to other birds — often across country borders. Some of these migratory birds don't seem to get sick from bird flu, but domesticated birds like chickens and turkeys can die from it.

A bird can get bird flu from another bird by coming into close contact with its infected feces (poop), secretions, or saliva. Birds can also get sick if they come into contact with dirt, cages, or any surfaces that have been contaminated by sick birds. That's why researchers think live bird markets, where birds are kept in close quarters, are places where the virus has spread quickly.

The virus can also spread from farm to farm if birds' infected feces and saliva get on farming equipment, like tractor wheels, clothing, and cages.

It's unlikely that a person who gets infected with the H5N1 strain of the avian flu will spread it to other people. All the human cases of bird flu so far have happened because people got it directly from infected birds. These people lived in rural areas, where many families keep small household poultry flocks that they butcher themselves. Poultry also roam freely in some of those areas, and there are lots of opportunities to be exposed to their infected feces.