Genetic Clue Pursued in Families Struck by Bird Flu
Wednesday, February 15, 2006
BANDUNG, Indonesia -- Buenah's teenage daughter lay sprawled on a hospital bed, under observation for bird flu. In an adjacent room, her haggard husband was sitting wrapped in a gray blanket, also under treatment for the virus.
Her two other children had already died from it.
"I don't know exactly why I'm healthy," Buenah admitted from a cot where she was keeping vigil late last month for her family. "I don't have a fever, a cough or other symptoms. I really don't know why not."
In the weeks before the family became sick, the virus raced through their small flock of chickens. When the last six birds developed symptoms, Buenah's husband helped his brother slit their throats beside a large palm in the front yard. The chickens were plucked and cooked in coconut milk for a family feast.
With four cases confirmed or suspected, her family represents one of the largest clusters of bird flu among humans in the world. It is also notable in sharing a characteristic with nearly all the other family clusters: Those infected by the virus were related to each other by blood and not by marriage. This raises the possibility that genetics play a role in determining who among those exposed contracts the often-lethal disease.
"It's intriguing," said Sonja J. Olsen of the Centers for Disease Control and Prevention in Bangkok, who has studied family clusters of avian influenza. If a biological explanation were ultimately proved, she added, "perhaps we could identify people at genetic risk."
Since bird flu began spreading across Asia in 2003, there have been 25 recorded family clusters involving confirmed or suspected cases. In the overwhelming majority, these have involved blood relations such as siblings, parent and child, children and grandfather, or niece and aunt. In only three instances did both husband and wife test positive.
Worldwide, bird flu has infected at least 165 people and killed 91, according to the World Health Organization. Health experts warn that the notoriously changeable influenza virus could develop into a form more easily transmitted among people and spark a global pandemic.
Outside the isolation ward in Hasan Sadikin hospital, a facility designated to treat bird flu in Bandung, the capital of West Java province, Buenah's relatives were camped on the lobby floor, spending nights on thin woven mats, wondering, like the experts, why she was spared while the rest of the family fell sick.
"It's a mystery. It's really incomprehensible to us," said Surip, her husband's cousin. "Everyone in the family had the same contact with chickens."
There is no evidence that properly cooked poultry or eggs can be a source of infection, according to the CDC. Most cases of bird flu in humans have resulted from direct or close contact with infected live or uncooked poultry or surfaces contaminated with secretions and excretions from infected birds.
The Buenahs live about 100 miles east of Jakarta in the village of Cipedung, in the modest dwelling of a meatball peddler, with dirt floors, flimsy bamboo walls and a ramshackle roof that leaks in the rain. Chickens often wandered inside, sleeping beneath the platform beds.