How Easily Is Bird Flu Spread?
Study in Vietnam Shows Handling of Sick or Dead Birds Is the Biggest Risk
Jan. 9, 2006 -- Bird flu may pass more easily from poultry to people than expected, according to new research.
The finding comes from an area of Vietnam where poultry have had flu caused by the H5N1 virus. The virus has mostly been seen in birds in Asia and Europe. In rare cases, it has spread to people.
The study appears in the Jan. 9 edition of the Archives of Internal Medicine.
Vietnam has been hit hardest by bird flu, with 42 human deaths out of 93 confirmed cases, according to the World Health Organization (WHO).
New cases have also been reported in Turkey. Two siblings in Turkey recently died of flu caused by the H5N1 virus, according to the WHO. Both victims were children; another child in that family has also died, reportedly of bird flu, but the WHO has not confirmed H5N1's role in that child's death. According to news reports, a doctor who treated those children speculated that the kids had probably caught the virus by playing with dead chickens.
The U.S. government has urged Americans to make of H5N1 virus among people. So far, the and doesn't seem to be very good at spreading between people.
Flu may spread more easily than thought from birds to people, write Anna Thorson, PhD, and colleagues. Thorson works at Karolinska University Hospital in Stockholm, Sweden.
However, no medical tests were done to check for the H5N1 virus in the study's participants or poultry.
Study in Vietnam
More than 45,400 people in a rural Vietnamese province were studied.
They were asked if they had had any flu-like symptoms within the past six months and whether they had kept or handled any poultry during that time.
Anyone who said "yes" to either question was interviewed in person.
Most people kept poultry at home, and many worked with poultry. For instance:
- 84% lived in homes where poultry were kept.
- About one in four (26%) lived in homes that had had sick or dead birds.
- A third worked with manure made from poultry feces, and almost as many raised poultry for a living.