A Key Institution
One of Washington's more obscure but important institutions is the Armed Forces Institute of Pathology in Rockville. It provides pathology services for the military, including autopsies of war dead. It also functions as a kind of Supreme Court for difficult cases. Pathologists unsure of a diagnosis, for a small fee, can consult its experts and send them microscopic slides or other samples for review. Part of the institute's value lies in its pathological specimens dating to 1862 -- 3 million pieces of preserved human tissue.
Jeffery K. Taubenberger is a civilian pathologist who heads the institute's division of molecular pathology. His laboratory is one of the few in the country with expertise in rescuing and restoring genetic material from damaged or decayed tissue. In 1995, Taubenberger wondered whether it might be possible to get the 1918 virus out of dried and fixed tissue from the Spanish flu pandemic. "I really wanted to see if there was some way we could make use of this vast, wonderful collection for this," he recalled.
He and his colleagues reviewed slides of lung tissue from 78 soldiers who had died in the pandemic. They narrowed the search to 10 slides in which the microscopic appearance showed that the men died only of viral pneumonia, not of a secondary bacterial infection that was more often the cause of death.
They tested preserved, leftover pieces of lung tissue from all 10. Two came up positive for influenza A, the broad family that includes Spanish flu. One was from a 21-year-old private who died in South Carolina on Sept. 26, 1918. The other was from a 30-year-old private who died in Upstate New York on the same day.
Using polymerase chain reaction (PCR) technology to amplify the genetic material, and primers -- short, important stretches of genetic material -- from human, animal and bird viruses, Taubenberger, Ann H. Reid and Thomas G. Fanning fished out fragments of the 1918 microbe. There were multiple copies of the virus in the sample, but they had broken into small pieces. Matching the overlapping ends of the fragments, the researchers reassembled the fragments in the right order.
The first gene they recovered, called NS, was virtually identical in the two cases.
Influenza A has eight gene segments. When Taubenberger published the report on the first one, Hultin read it. He realized, at long last, that there might be value in dead Spanish flu virus -- and he thought he might still have a source. He contacted Taubenberger and asked if he would be interested in frozen organs of 1918 victims, should any still exist. Taubenberger said yes. Hultin set off two weeks later.
He returned to Brevig Mission and again sought permission from the village council to dig. "I said that the virus was dead in 1951 and was even deader now," he recalled.
The village leaders talked a long time in Inupiat, the local language. They were worried about the release of evil spirits, not contagion, Hultin said. Then someone recalled that the victims had received Christian burials, which were supposed to have chased away the evil spirits. Permission was granted.
On Aug. 20, 1997, Hultin and a local crew opened the grave. The four bodies he had sampled in 1951 were decomposed. But he found one that had been missed the first time. It was of a woman in her thirties who was very fat. All that was left of her clothes was a row of bone buttons lying on her chest. But her body was intact and frozen, apparently insulated by the fat from the occasional brief thaws. "I sat on an upside-down pail and I looked at this, and I got the flash in my mind," Hultin said. "Maybe this is where I can find it."
With only gloves and a face shield for protection, Hultin removed her lungs and sampled her spleen, liver and heart. He cut the tissue into one-inch cubes and put them in a preservative solution. The grave was closed for a final time.
Hultin and Taubenberger hoped the Alaska material would contain virus material that was more nearly intact than the material from the soldiers. It did not. In fact, it was a bit more fragmented. The longest strands of RNA -- flu's genetic material -- in the institute's slides were about 130 nucleotides, or letters, long. In Hultin's material, the longest was 110.
Nevertheless, Hultin had provided Taubenberger with all the material he would need to reconstruct the 1918 virus. Eight years later, it was done.
