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Monkey Virus Infects WorkersEmergency meeting called for 81 Tunney's Pasture workers; 'Virus in search of a disease' strikes fear into employees of Health Canada Source: http://www.ottawacitizen.com/national/010629/5027025.html Matthew Sekeres At least two workers at a Health Canada research centre in Ottawa have been infected with a mysterious and rare virus from lab monkeys. Eighty-one employees from the Sir Frederick Grant Banting Research Centre in Tunney's Pasture were called to an emergency meeting on Wednesday during which they were told that two workers -- and possibly a third -- tested positive for Simian Foamy Virus during a study last month of 46 anonymous blood samples. Employees at the centre, who were described as shocked by the announcement and fearful of the consequences, were also bluntly warned not to donate blood, tissue or organs until further tests pinpoint exactly which workers are infected with SFV and how many more might have been exposed. A spokesman from Canadian Blood Services said last night that Health Canada informed the agency about the SFV infections on Wednesday and suggested that potential blood donors who work with lab animals may have to be subject to special screening in the future. Health Canada has also offered to test the spouses and family members of any infected individuals. The ministry discovered the virus in 80 per cent of its macaque monkey colony following tests completed in April 2000. Last month, the department conducted a blind study with 46 of the 81 employees who volunteered. The two positive samples were discovered June 11 and 12, while a third sample is being re-evaluated. The third sample is "not yet known to be positive (and) not clear that it is negative," said Karen Dodds, director general of Health Canada's Food Directorate. "The purpose of the original (blood tests) was to determine whether there was any risk of Simian Foamy Virus in animal handlers and to determine what impact, if any, it might have on Canada's blood supply," she said. "We're recommending that any staff who have had contact at the present time or in the past -- either with the animals themselves or with their blood, organs or tissues -- that they enroll in the link study." "There are likely more staff who have had exposure" to the monkeys, Ms. Dodds added. At the emergency meeting two days ago, employees were given information packages -- a copy of which has been obtained by the Citizen -- explaining the study, providing information on SFV, listing interim recommendations and outlining the ministry's next steps. A second staff meeting will be held today, in which the ministry will present its plan for the follow-up test. SFV has been referred to as the "virus in search of a disease" because it has the capacity to incorporate itself into DNA and because it is transmitted routinely between non-human primates. Dr. Jonathan Allan, a virologist at the Southwest Foundation for Biomedical Research in San Antonio, Texas, says SFV "has been called 'the virus in search of disease' because it's a retrovirus -- so you think, in the right circumstances, it might do something. If it ever got into the population, since it's a retrovirus, it's something you would prefer not to have happen." SFV has been around since the 1950s and is present without symptoms in almost all non-human primates, said Dr. Allan. It is transmitted orally between monkeys, baboons and other primates. "Retrovirus integrate their genetic material into your chromosome, so they essentially become part of you," he added. "If they incorporate themselves in the right place, they can induce cancer genes. And that's happened in animal models." But there have been less than 20 documented cases of human infection worldwide, and none of the people infected has shown symptoms of any disease. The Health Canada results also represent the first transmission between macaque monkeys and humans. "What we do know about this particular virus is that it is unlikely to have any negative effects on people," said Dr. Allan. "For whatever reason, and we don't even know why, it doesn't appear to be one of these disease-causers. But you have to be cautious. You can't say, 'Well it's only Simian Foamy Virus, don't worry about it'. The ministry does not yet know exactly how many employees could have had contact with the animals or their organs and fluids. Some employees have since moved to a research facility in Winnipeg, while others have retired or taken other jobs. "The information that we have so far is that Simian Foamy Virus causes no adverse health effects, either in the animals or in the humans known to be infected," Ms. Dodds said. "But we know that retroviruses, when they do cause adverse health effects, have a long latency period, so we will continue to monitor those individuals who we know to be positive." Two previous studies of foamy virus infection by the U.S. Centre for Disease Control and Prevention did not find any transmission between human spouses on a pool of five subjects. "There hasn't been a lot of work in this area. As far we know, there doesn't appear to be any kind of association, at least in the monkeys, with disease," Dr. Allan said. There are three groups of retroviruses known to infect humans. Foamy viruses are not linked to any human or animal disease but others, like Human T Cell Lymphotropic Virus (HTLV) are know to cause cancer in a small percentage of people while others are linked to HIV, the retrovirus causing AIDS. The fact the virus originated with macaque monkeys is also significant, Dr. Allan said. "There are different strands that could be transmitted to humans. It's always possible that one of the monkey strains is more pathogenic (disease-causing) than another." Previous positive tests have come from individuals with high levels of exposure to primates -- typically 20 years, according to Dr. Allan. He added that laboratory precautions over the last 20 years have also been designed to prevent transmission of primate viruses to humans, meaning that those employees with longer tenures in the research centre would be more at risk. The Health Canada colony of roughly 275 macaque monkeys is located in the animal wing of the research centre. It was being bred from 1982 until 1997, when a report by the Royal Society of Canada recommended that the practice be stopped. The animals are available to scientists who meet ministry criteria for research purposes. At the moment, the animals are not being used. Health Canada Study The following contains excerpts of a memo distributed to Health Canada employees at the Sir Frederick Banting Research Centre at Tunney's Pasture:
Information on SFV
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