Traces of an avian flu virus, which has killed at least 18 people and millions of chickens across Asia, has been found in the nostrils of pigs near Hanoi. This could be a dangerous development, there is no indication yet that the pigs have actually been infected with the disease.
A United Nations scientists said Friday that the bird flu virus, spreading rapidly through poultry flocks in Asia -- has also been detected in the nostrils of two pigs.
The virus, a strain known as H5N1, has killed at least 13 people in Vietnam and five in Thailand. Health experts say most if not all of the victims caught the bird flu from handling live chickens, and it does not spread easily between people.
But news that the virus is present in pigs has alarmed flu experts, because pigs can provide a mixing place for animal and human viruses. The World Health Organization has warned that if the disease picks up human flu traits, the new strain could be passed from person to person, potentially causing a global pandemic.
However, Dr. Anton Rychener, who is currently running the Food and Agriculture Organization office in Vietnam, says the virus was only found inside the snouts of two pigs.
"Nasal swabs of pigs came back positive," he said. "[The] pigs...are on farms that are infected."
Chickens infected with bird flu shed high concentrations of the virus in their feces. When the waste dries out it can travel as dust and infect other birds -- and perhaps other animals as well.
Dr. Rychener says the pigs might have inhaled the virus-filled dust, but are not necessarily infected with the disease.
He says blood samples have been taken from the pigs, and are now being examined for signs of infection.
Tens of millions of chickens have either died or been slaughtered in mass culls aimed at containing the disease.
WHO experts have said human cases might have gone undetected in some countries, especially China and Indonesia, where authorities were slow to confirm outbreaks.