June 21, 2006
Ignorance a key factor in H5N1 infections: experts
By Fitri Wulandari
JAKARTA (Reuters) - Many people who contracted the H5N1
bird flu virus in Indonesia were ignorant and never warned
about the disease and children are the ones most vulnerable,
medical experts said on Wednesday.
"Children may be off to play with sick chickens ... an
activity that adults do less of," Thomas Grein, a leading
epidemiologist at the World Health Organization, told Reuters
on the sidelines of an experts meeting on bird flu.
"Other high risk exercises are slaughtering of sick birds,
de-feathering and preparing food. But if you wash your hands,
it can reduce that risk very dramatically," he said. "But
again, this is less often done by the younger person than
The H5N1 virus has infected 51 people and killed 39 of them
in Indonesia since 2005 and is now endemic in poultry in nearly
all of the country's 33 provinces.
It is common in the far-flung country of 17,000 islands for
households to keep chickens for food and extra income - which
means that everyone, and not just poultry workers, is at risk.
School-age children and children less than 10 years of age
make up over 40 percent of Indonesia's H5N1 human infections.
People are not used to the idea that sick birds could be
dangerous and children play with chickens and are sent to clean
up after them.
"It shows that the risk profile is much broader than we
expected. It's not only poultry workers. This is because the
virus is found so widely in backyard chicken," said Steven
Bjorge, WHO's medical officer of communicable diseases.
"There were other diseases in birds but they did not cross
over to humans in the past. That's the situation that they are
not familiar with," he said.
"People need to understand that dead chickens are a high
risk factor. If there is dead chicken, they need to call the
authority to clean them properly and should not let children
NOT JUST INDONESIA
In Hong Kong, where the virus made its first documented
jump to humans in 1997, nine of the 18 human infections
involved children who were six years old or younger.
The first victim was a three-year-old boy who died 12 days
after he developed fever, a sore throat and a cough in May,
1997. While experts never confirmed how he came to be infected,
he attended a nursery which kept chicks and ducklings in a pet
At least two other children attended a school that was next
to a wholesale market and often played in an area used to store
chicken cages that were unwashed and splattered with feces.
H5N1 infected birds shed plenty of virus in their feces and
experts say stool particles are a main vehicle of transmission.
Kept moist and cool, the virus can survive for days on feces.
"If chickens infected with H5N1 are shedding the virus in
their feces on the floor of houses where people live, then they
are more likely to be exposed to H5N1 infection," said Julian
Tang, a microbiologist at Chinese University in Hong Kong.
"The virus may survive for some time in the chicken feces,
then when dry, can be inhaled as dust. This may occur if the
feces on the floor is disturbed by walking, playing. You can
breathe or have direct contact with it, when you are just
present in the area, whether sleeping or doing other things."
"Children are probably more vulnerable because they tend to
play on the floor, more often, where the risk of contact with
such infected material is higher. If they are sent to clean up
dead chickens, well, you have your answer," Tang said.
Ignorance is also believed to have played a role in the
deaths of four young Azerbaijanis in February and March, who
de-feathered dead swans to make pillows before they fell sick.
Feathers too may infected an 18-year-old Indonesian
shuttlecock maker, who died last month. While officials have
not said how he got infected, he sorted feathers for a living.
"Infected birds preen their feathers which could be
contaminated with beak excretions. The virus would then be
transferred to the person by hand or breathing in feather dust
contaminated with virus," said John Oxford, virology professor
at the Royal London Hospital.
(Additional reporting Tan Ee Lyn in Hong Kong)