![\"keim\"](\"http:\/\/stage.headlessnauedu-b6hgdzckfdgxgzhe.westus-01.azurewebsites.net\/wp-content\/uploads\/2013\/02\/keim.jpg\")
\nPaul Keim<\/p>\n
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Led by Northern Arizona University Regent\u2019s professor\u00a0Paul Keim<\/strong>\u00a0and NAU professor emeritus\u00a0Jim I. Mead<\/strong>, now professor and chair of geosciences at East Tennessee State University, the researchers have molecular data that indicate the presence of North American anthrax far earlier than anyone had previously believed.<\/p>\n \u201cThe dispersal of anthrax throughout the continent required relatively recent movement by European colonizers,\u201d Keim said. \u201cBut the continent\u2019s first human inhabitants may have seeded the initial North American anthrax populations in the far north.\u201d<\/p>\n Keim, who also is director of the Pathogen Genomics Division for the Translational Genomics Research Institute in Phoenix, explained that high resolution genomic analysis coupled with extensive strain collections enhanced the team\u2019s ability to reconstruct ancient epidemiological occurrences.<\/p>\n Mead said that during the last Ice Age\u2014more than 14,000 or so years ago\u2014inhabitants could walk from Siberia over to Alaska but then would be confronted with a wall of ice from northern Alaska south to about Seattle.<\/p>\n \u201cThis continental ice sheet barrier kept Beringian plants and animals up north and west, while south of the ice (about where the Canadian and U.S. border are today) were different biological communities,\u201d he said. \u201cIt appears from the molecular data that anthrax was not south of the ice barrier.\u201d<\/p>\n About 14,000 years ago the ice barrier melted enough to create a corridor between Beringia and the continental United States.<\/p>\n \u201cAt some point anthrax appears to have steadily moved south into what is now the United States,\u201d he said. \u201cThis corridor would have permitted some species to continually move south\u2014nothing was stopping them.\u00a0Various animals apparently did this dispersal\u2014bison being one of them and humans another.\u201d<\/p>\n Disease introduction into the New World during European colonial expansion is well documented and had a major impact on indigenous populations, Keim explained. \u201cHowever, few diseases have been associated with early human migrations into North America.\u201d<\/p>\n Bacillus anthracis<\/em>\u2014the bacterium that causes anthrax\u2014has dispersed globally through commerce and trade of animal products contaminated with\u00a0B. anthracis\u00a0<\/em>spores, according to Keim.<\/p>\n Without human involvement, infected animals typically die within seven to 10 days, seeding only the surrounding soil with spores and keeping the spread of the disease relatively contained. The potential for dispersion even among migratory herds is limited since infected animals typically die quickly before extensive dispersal can occur.<\/p>\n Historically, an animal that died of anthrax was scavenged by people for its hair, hide, and bones and was even consumed, helping the dispersal of spores well away from a carcass.<\/p>\n Imported spore-contaminated animal hides account for many of the recent U.S. human anthrax cases, though such modern cases rarely result in dispersal.<\/p>\n \u201cWith the exception of the most recent human cases, the current distribution of\u00a0B. anthracis\u00a0<\/em>can be traced to historical human dispersion, trade and migratory patterns,\u201d Keim said.<\/p>\n Anthrax is a potentially fatal disease caused by the bacterium\u00a0Bacillus anthracis<\/em>. It usually develops in livestock and is relatively rare in humans, unless deliberately spread.<\/p>\n Some scholars believe the fifth and sixth biblical plagues of Egypt told in Exodus were anthrax caused.<\/p>\n Keim is one of the investigators who linked the 2001 anthrax-letter attacks that killed five people and sickened 17 to the U.S. Army Medical Research Institute for Infectious Diseases in Frederick, Md.<\/p>\n Bruce Ivins, an Army researcher, committed suicide in 2008 as federal agents were preparing to charge him with carrying out the attacks.<\/p>\n In addition to Keim and Mead, the research team includes\u00a0Leo J. Kenefic<\/strong>,\u00a0Talima Pearson<\/strong>,\u00a0James M. Schupp<\/strong>,Wai-Kwan Chung<\/strong>,\u00a0Jodi A. Beaudry<\/strong>, all of Keim\u2019s Center for Microbial Genetics and Genomics;\u00a0David Wagner<\/strong>, NAU assistant professor of biological sciences; Jacque Ravel, from the Institute for Genome Sciences, University of Maryland School of Medicine; Alex R. Hoffmasters, of the Bacterial Zoonoses Branch, Centers for Disease Control and Prevention in Atlanta.<\/p>\n Mead now believes the next step is to travel to Siberia to \u201cfind frozen critters\u201d that may indicate anthrax. \u201cIt wasn\u2019t just bison carrying anthrax; it was people and other animals,\u201d he said. \u201cWe now need to go back into the Ice Age.<\/p>\n","protected":false},"excerpt":{"rendered":"\n\n
\n ![\"mead\"](\"http:\/\/stage.headlessnauedu-b6hgdzckfdgxgzhe.westus-01.azurewebsites.net\/wp-content\/uploads\/2013\/02\/mead.jpg\")
\nJim Mead<\/p>\n
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