Will climate change bring back SMALLPOX? Siberian corpses could ooze contagious virus if graveyards thaw out, claim scientists ......................... It was one of the world’s most feared diseases that covered a person’s body in painful pus-filled spots. And scientists fear that smallpox, which was eradicated in 1979, could re-emerge from the most unlikely of places – defrosting corpses. A handful of experts fear that bodies infected with the disease, which are defrosting in Siberia - having become exposed from melting frost – could potentially begin a cycle of infection, should a person make contact with the remains. Concerns have been raised for years, but a newly-discovered giant 30,000-year-old virus found in Siberian permafrost has led Frances National Centre for Scientific Research (CNRS) to warn that the prospect of a smallpox comeback cannot be ruled out. A report by BBC Future questioned whether frozen bodies of people who had smallpox – and might have died from the disease – could release the virus into the environment. If such a scenario did occur, it could potentially start a global pandemic. The question has been the source of speculation for over a decade as scientists believe the disease could be in suspended animation in bodies that are surfacing as a result of the warming climate, Gizmodo reported. In 2002, author Richard Stone wrote an article for Science asking whether smallpox is lurking in the Arctic. He described a ‘nightmarish place near the Kolyma River’ in north eastern Siberia where authorities in Yakutsk gathered a team of people to investigate remains of bodies from the 18th century with smallpox scars as they were worried that flooding could resurrect the virus. The revival of viruses that are considered to have been eradicated, such as the smallpox virus, whose replication process is similar to that of Pithovirus, is no longer limited to science fiction. The risk that this scenario could happen in real life has to be viewed realistically. Imre Friedmann, who examined the smallpox-scarred body found at the Kolyma River said: If bacteria survive, I don’t see why viruses don’t survive. Another expert, Donald Henderson, an epidemiologist at Johns Hopkins University, said the hardiness of the smallpox and the expanse of frozen tundra means that it is possible that viable variola is preserved in permafrost. If it were going to be anywhere... [the tundra] would be the likely place, he said and experts think dry permafrost is probably where it would be found. However, scientists who have tried to excavate corpses with the tell-tale signs of smallpox in Alaska and Siberia have not recovered any viable viruses from them. The World Health Organisation told MailOnline: Our experts cannot confirm that live virus could be recovered from archaeological relics. A U.S. CDC publication said that while living organisms in relics seem to be non-existent, nevertheless, archaeological specimens should be handled with caution. Each situation should be approached independently and with vigilance and attention. Dr Kevin Brown, Lead Clinical Virologist for Public Health England told MailOnline: Although short lengths of smallpox viral DNA has been detected in corpses in the permafrost in Siberia and other preserved historical artefacts, no infectious virus has ever been obtained from archaeological remains. There is no evidence that previously frozen corpses in the permafrost are a potential source of infectious smallpox virus. Michael Lane, retired director of the Centre for Disease Control and Prevention’s smallpox eradication programme, which ran during the 1970s and early 1980s, said: ‘No one feels theres a serious chance that global warming will melt the permafrost and unleash an epidemic.’ Other scientists think that climate change actually reduces the chance of finding the smallpox virus, as it is unlikely that it could spend a number of days unfrozen. Jonathan Tucker, a senior fellow at the Centre for Nonproliferation Studies, said: The gradual thawing of the permafrost brought about by global warming [further diminishes] the likelihood of recovering infectious smallpox virus particles from the corpses of victims buried in the Arctic region. SCIENTISTS REVIVE 30,000-YEAR-OLD GIANT VIRUS FROM SIBERIAN PERMAFROST LEADING TO FEARS THE REVIVAL OF VIRUSES IS POSSIBLE Last week, scientists announced they have successfully revived a 30,000 year old giant virus frozen in ice. The French and Russian researchers said that the virus is a type never seen before and warned that global warming could lead to more ancient viruses that can affect humans being uncovered. The virus was identified by taking a culture of amoebas found in the permafrost, and adding some of the permafrost. Dubbed Pithovirus sibericum, the virus was found in a 98ft (30metre) deep sample of permanently frozen soil taken from coastal tundra in Chukotka, near the East Siberia Sea, where the average annual temperature is minus 13.4 degrees Celsius (7.8 degrees Fahrenheit). The team thawed the virus and watched it replicate in a culture in a petri dish, where it infected a simple single-cell organism called an amoeba. They found the cells exploded, and when examined under a microscope, showed the presence of a giant virus particle known as a pandovirus. Radiocarbon dating of the soil sample found that vegetation grew there more than 30,000 years ago - a time when mammoths and Neanderthals walked the Earth, according to a paper published in the U.S. journal Proceedings of the National Academy of Sciences (PNAS). P. sibericum is, on the scale of viruses, a giant -- it has 500 genes, whereas the influenza virus has only eight. It is the first in a new category of viral whoppers, a family known as Megaviridae, for which two other categories already exist. P. sibericum is harmless to humans and animals because for it only infects a type of amoeba called Acanthamoeba, the researchers said. The work shows that viruses can survive being locked up in the permafrost for extremely long periods, Frances National Centre for Scientific Research (CNRS) said in a press statement. It has important implications for public-health risks in connection with exploiting mineral or energy resources in Arctic Circle regions that are becoming more and more accessible through global warming, it said. The revival of viruses that are considered to have been eradicated, such as the smallpox virus, whose replication process is similar to that of Pithovirus, is no longer limited to science fiction. The risk that this scenario could happen in real life has to be viewed realistically. .
Posted on: Mon, 10 Mar 2014 15:59:30 +0000
Trending Topics
Recently Viewed Topics
© 2015