- Birds are a natural reservoir for influenza viruses that sometimes jump to humans.
- H5N1 strains in particular have some virologists worried because mortality may be high among the few people who have been infected, mainly from direct contact with birds.
- After the September 11 attacks, biodefense spending soared, leading to recent research on H5N1 lab-made strains that are transmissible among mammals.
- This work set off a debate between biodefense experts, who argue that the new H5N1 strains are potentially dangerous and want restrictions on research, and scientists, who argue that research on dangerous pathogens is important for improving surveillance of natural outbreaks and that hampering such work would do more harm than good.
The chickens were already getting sick when Yoshihiro Kawaoka arrived in the U.S. in August 1983. A few months before, in April, a bird flu virus had arisen in the poultry farms of eastern Pennsylvania, but veterinarians had deemed it to be “low pathogenic”—meaning it made chickens sick but did not kill many of them. As the virus swept through the poultry farms, however, a new strain developed. Chickens began to die in large numbers, and farmers started to fear for their livelihoods. The state called in the U.S. Department of Agriculture, which set up a temporary command and control center in a strip mall outside of Lancaster. To contain the epidemic, it culled 17 million birds from Pennsylvania down through Virginia.
Kawaoka was a young researcher from Japan who was starting work at St. Jude Children’s Research Hospital in Memphis. His boss, virologist Robert Webster, had a theory that human influenza viruses originate in bird populations—that they circulate harmlessly among ducks and geese and that, every once in a while, a strain will evolve the ability to live in the human upper respiratory tract. To combat human influenza, Webster asserted, you first had to understand bird flu. In November, when Webster heard that the outbreak had become serious, he dropped everything and headed to its epicenter.
This article was originally published with the title Waiting to Explode.