THURSDAY, Oct. 6 (HealthDay News) -- Researchers have pieced together the genes of the Spanish influenza virus responsible for the 1918 pandemic that killed nearly 50 million people worldwide. The finding may help shed light on why the virus was so deadly in young, healthy individuals and may help the world prepare for an inevitable outbreak of avian flu, according to their report in this week's Science.
Under strict biosafety isolation, Terrence Tumpey, Ph.D., of the U.S. Centers for Disease Control and Prevention, and colleagues inserted eight genes from the 1918 virus, either separately or in combination, into a contemporary influenza virus. They recovered the genes from formalin-fixed autopsy tissues and from a 1918 flu patient buried in Alaskan permafrost.
Mice infected intranasally with the 1918 virus lost up to 13% of their body weight at two days post-infection and died as early as three days, much sooner than any other human virus. Cultured human bronchial epithelial cells inoculated with the 1918 virus released 50 times more viral progeny than the control strain, and bronchial tissue from infected mice showed a high level of inflammation and edema, similar to preserved autopsy specimens.
The authors conclude that the polymerase and hemagglutinin genes seem to confer the high virulence associated with this viral strain. Science's chief editor, Donald Kennedy, said in a statement that this dangerous work is "necessary for developing drugs and vaccines that could help prevent another global flu pandemic," and the benefits outweigh the risks of working with the virus.
Abstract
Full Text (payment may be required)
