In the heart of Thailand's poultry industry, a deadly virus is stalking healthy flocks of birds. In the past year recurring outbreaks of bird or avian flu have left millions of chickens dead.
And what the virus didn't kill the Thai government did, fearing the virus could decimate the industry.
But the virus isn't just in Thailand. It's in at least eight Asian countries — and not just in chickens, but in ducks, migratory birds, pigs, house cats, tigers and, in rare cases, humans.
Dr. Scott Dowell, from the U.S. Centers for Disease Control, is in Thailand trying to stop the flu from spreading and killing. The U.S. and Thailand are working together to find ways to control this virus that kills seven of every ten people who contract it. Normal influenzas kill about one in 100.
"Certainly this virus now is one of the deadliest viruses that affects humans," says Dowell. "The good news is, it doesn't affect very many."
Only 46 people have died since last year, when it jumped from animals to humans. But viruses can mutate and that's a huge worry with avian flu.
The biggest fear right now is of a pandemic — a global epidemic that could result if this virulent form of avian flu were to combine with the very common human flu. The end result could be a deadly strain of influenza that could be easily transmitted, human to human, through a cough, sneeze, or even a handshake.
Experts say bird flu is now found across so much of Asia that it can't be beaten with vaccines because it's always changing characteristics. So the goal, they say, should be to control it.
"We can take measures both to manage cases and reduce mortality," says Dr. William Aldis with the World Health Organization. "Also to prevent and limit epidemic spread."
In Thailand that means new regulations at poultry farms, including disinfection of clothing and cars and improved monitoring of birds and humans for flu symptoms. A push is also on to supply powerful drugs to combat an outbreak before it becomes a global threat.