June 21, 2006
Ignorance a Key Factor in Bird Flu Infections
By Fitri Wulandari
JAKARTA -- 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 adult."
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 touch them."
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 zoo.
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)