Digging up the deadly past
The 1918 Spanish Flu was history's deadliest disease, estimated to have devoured upwards of 50 million lives and ravaging one-fifth of the world population within two years. So lethal and feared was the pandemic that it became customary for victims to be sealed in lead-lined caskets to prevent viral particles from spreading. It is curious, then, in the midst of this year's flu season, that scientists have risked a repeat outbreak by resurrecting long-dormant influenza specimens that were interred 90 years ago with their victims.
Such was the case last week when Prof John Oxford, a leading virologist at London's Queen Mary's College, exhumed the body of Sir Tatton Benvenuto Mark Sykes, a British diplomat and adventurer. Professor Oxford suspects that the corpse of Sir Mark, who fell ill in 1919 to the avian epidemic at 39 years old, may solve some riddles about how the Spanish Flu emerged in the human population. Understanding that could shed light on the H5N1 "bird flu" strain currently gripping parts of the world, explained Dr Alan Hay, the director of the World Health Organization's influenza centre at the National Institute for Medical Research in London.
"It's about lessons of the future and people just want to understand as much as possible," he said. The possibility that the Spanish Flu was the ancient predecessor to the modern avian flu is the key, as victims in 1918 died from overly aggressive immune responses that attacked their own bodies - a phenomenon seen nowadays in human H5N1 patients. Dr Hay said experts believe that learning how the 1918 virus functions will help them in their quest to develop vaccines against future pandemics and prepare for when the H5N1 inevitably mutates.
"The actual agent causing influenza was not identified until the early 1930s, so people now trying to obtain samples from humans, birds and animals are trying to understand how the 1918 virus came into being," Dr Hay said. "If it was already in the human population, what changes occurred to make it so highly pathogenic?" But there is also great danger of triggering what Prof Oxford has called an "Armageddon scenario" - the possibility that during the act of exhuming a body, the 1918 virus could genetically recombine with the current strain and awaken another major epidemic.
Some contend that studying the infected remains may be worth the risk if it can help scientists better understand ways to fight a future outbreak. Controversy aside, pathologists have been searching for and exhuming the bodies of Spanish Flu victims for years. A decade ago, an expedition in Norway sought the permafrost-preserved bodies of seven dead miners that were believed to harbour the virus. At the time, the American biologist Paul Ewald billed the expedition as "one of the most dangerous things people have ever done".
The team of researchers embarked to the small Norwegian mining town of Longyearbyen. Dr Kirsty Duncan, a Nobel Prize-winning medical geographer and associate professor at the University of Toronto, was one of the lead scientists among them. "I was horrified we didn't know what caused [Spanish Flu], and also knew that if we could find fragments of the virus, we might be able to find a better flu vaccine," the Canadian scientist said. "I spent two years searching for victims. In two years, I put together an international research team and I spent two years getting permission to exhume the victims."
Ultimately, however, the project was a disappointment. Dr Hay, who is also familiar with the 1998 ground survey, said the bodies of the long-deceased miners were expected to have been buried in the permafrost, thus leaving the virus intact. But that was not the case. "Either the coffins had risen gradually over time, or they hadn't been buried as low as expected, but they were certainly not in the permafrost," he said. "Preservation of the material was insufficient to allow the virus to survive."
Dr Hay acknowledged that such expeditions can be controversial because of the potentially hazardous implications. Still, that has not stopped researchers from going to great lengths to learn all they can about Spanish Flu. In 2005, American scientists were able to synthesize a living copy of the deadly flu bug behind the catastrophic 1918 epidemic. To Dr Hay's knowledge, that reproduced strain housed in Atlanta's Center for Disease Control virology unit is the only copy.
"We've been able to use PCR (Polymerase Chain Reaction) techniques to dramatically amplify small amounts of genetic material," Dr Hay explained. "They've been able to amplify traces of the genes of that virus to determine the genetic secrets and piece together the genome like a jigsaw." As for the act of exhuming bodies to study 90-year-old viruses, he said all precautions are taken to prevent disease from spreading.
"The chance that the virus is still viable is also very low because usually people are just trying to get bits of genetic material and that's not infectious," he said. But he added that "because there is that possibility, extreme caution is taken in handling corpses and anything derived from them. They're handled under very high containment conditions." Pathologists have noted that pandemics have a habit of appearing in intervals of 11 years or 40 years - from 1918's Spanish Flu to the 1957 virus, and then another in 1968 and the re-emergence of the H5N1 virus in 1977. If the trend persists, that would make this generation due for another round.
"There is a periodicity here but it's not a very definitive one," Dr Hay said. "Once one epidemic is getting to 40 years [since the previous outbreak], the community becomes more and more concerned that something is just around the corner." For that reason, most countries have developed plans for dealing with pandemics now, and many have established stockpiles of drugs as a first line of defence before a vaccine is available.
"There's this heightened perception that another pandemic - whether caused by H5N1 or another virus that may not be present in the population at the moment - is a very significant threat," he said. "The point is everyone thinks back to 1918 and remembers how devastating a pandemic can be, so it's important to uncover the nature of that virus sooner so we have a better understanding of what we're dealing with now." firstname.lastname@example.org
Published: September 25, 2008 04:00 AM