WASHINGTON -- A specimen of the influenza virus that killed 21 million people in the 1918 worldwide epidemic has been recovered from the frozen remains of a flu victim buried in Alaska.
Researchers at the Armed Forces Institute of Pathology announced Thursday that biopsy specimens from a frozen corpse exhumed from a cemetery in Brevig Mission, Alaska contain genetic material from the killer flu.
Experts have said that analyzing the 1918 virus genetic pattern will help science learn how that particular virus was able to kill so many people worldwide and will help researcher prepare vaccines to protect against the virus if it breaks out again.
Army researchers last year identified the flu virus in preserved lung specimens taken during autopsies of soldiers killed by the flu in 1918 at military bases in Fort Jackson, S. C. and Camp Upton, N.Y.
The new specimen was taken from the lung of one of 72 people buried in a mass grave after the flu swept through Brevig Mission, then known as Teller Mission, in 1918. The small town lost 85 percent of its population in a single week.
Dr. Johan Hultin, a retired San Francisco pathologist, exhumed four bodies from the mass grave and found that one, an obese woman, was well-preserved. Tissue from her lung was later found to contain genes from the killer flu.
Dr. Jeffery K. Taubenberger of the Armed Forces Institute of Pathology said last year that the genetic pattern of the 1918 flu virus is unlike any other flu bug, but is closely related to the so-called "swine flu."
Taubenberger said that although the disease that caused the worldwide epidemic was called "Spanish flu," the virus apparently was a mutation that evolved in American pigs and was spread around the globe by U.S. troops mobilized for World War I.
The finding supports a widespread theory that flu viruses from swine are the most virulent for humans. Two other flu viruses spread worldwide since 1918 -- the Asian flu in 1957 and the Hong Kong flu in 1968 -- both mutated in pigs.
Most experts believe that flu viruses reside harmlessly in birds, where they are genetically stable. Occasionally, a virus from birds will infect pigs. The swine immune system attacks the virus, forcing it to change genetically to survive. The result is a new virus.
The 1918 flu genes were first isolated last year from the preserved lung tissue of an Army private who died at Fort Jackson, S.C. Army doctors in 1918 conducted autopsies on some of the 43,000 servicemen killed by the flu and preserved some specimens in formaldehyde and wax.
The 1918 flu epidemic caused about 700,000 deaths in the United States and about a quarter of the nation's population contracted the illness.