Flight patterns of some migratory birds match the spread of the
bird flu that has hit many Asian countries, experts say.
That may explain the fast spread of the disease across Asia.
"People have to be careful not to touch wild birds directly
while watching them in the forthcoming migratory season," said a
Beijing-based expert yesterday.
He included land birds, shore birds, gooses, ducks and birds of
prey in the list of possible disease carriers, although there is no
direct evidence to back the claim that migratory birds are in fact
spreading the H5N1 strand of avian influenza.
However, their quick flights could rapidly carry the virus from
one area to another, said Shi Guangfeng, a doctor with a hospital
attached to Shanghai-based Fudan University, in an interview with
the Shanghai Evening Post yesterday.
Shi said migratory birds are probably only a carrier of the
disease.
He said migratory birds may pass through infected poultry farms
and their toes and feathers may come in contact with infected
feces. The virus may be able to live for more than 10 hours or up
to several days in the feces of infected poultry.
Cui Zhixing, a researcher from Shanghai Natural Museum said, "we
can not rule out the possibility regarding the route of migratory
birds."
The fly paths of the area's migratory birds are rather wide,
with a diameter up to about 1,000 kilometres across most of the
Asia-Pacific area.
Most migratory birds like hooded cranes usually take off from
Northeast China or Siberia, pass through the Republic of Korea
(ROK) in the Korea Peninsula, then fly over Japan, which matches
the patch of the outbreak from ROK to Japan.
From Japan, migratory birds can fly downwards to the middle and
lower reaches of the Yangtze River and China's coastal areas
including Taiwan, he added.
Cu Guozhong, a researcher at the Beijing-based National Bird
Banding Centre, said that massive flights of migratory birds
usually moves from north to south in autumn and from south to north
in spring following changes of temperature.
(China Daily February 2, 2004)