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Editor, Senior Moderator
Source: http://www.canada.com/Health/Virus+hunters+overdrive/1604238/story.html
Virus hunters in overdrive
By Pauline Tam, Canwest News ServiceMay 16, 2009
OTTAWA ? Since the outbreak of swine flu, glass test tubes filled with mucus on a swab have been arriving ? by the pair, half-dozen, sometimes three dozen a day ? at the Ottawa laboratory where Susan Laporte works.
"The first few weeks, I think some people were spending most of the day working on these specimens," said Laporte, a medical technologist.
At her covered work station, she dons a face shield, visor, mask, gloves and special protective lab coat before handling the potentially hazardous microbes in those test tubes.
Each one is a question that awaits an urgent answer: Does this "nasopharyngeal swab," collected from the nose and throat of a patient with flu symptoms, test positive for the common strains of influenza that are known to virologists?
If not, could this sample contain the new strain of the H1N1 virus that has swept the globe?
The process of elimination falls largely to Laporte and her colleagues at the regional virology lab based at the Children's Hospital of Eastern Ontario.
Since the start of the flu outbreak, many of the lab's technologists have taken turns working seven days a week to handle the extra volume of diagnostic tests.
"People are working overtime, for sure," said Tim Karnauchow, the virologist who runs the lab. "We've had to tell people, 'You must keep track of your hours,' because most of them are saying, 'No, this is my duty.' They're very dedicated staff."
Typically, during the spring months, about a dozen samples are sent to the lab to be tested for respiratory illnesses.
"What this year represents is a respiratory season that refuses to die," said Karnauchow.
Because so little is known about the biology of the H1N1 flu virus, the screening process, involving three separate tests that isolate and identify suspect viruses, is far more exhaustive than tests for more common types of respiratory illnesses.
It can take up to two weeks, from the time a sample arrives at the regional lab to when a final verdict is issued from Toronto, for results of the flu test to reach patients.
For the virus hunters at the regional lab, the extra workload from the H1N1-flu outbreak comes with an added challenge: To provide as speedy and accurate a test result as possible without cutting corners. In this task, they are fighting a public perception, popularized by the TV series, CSI, that complex lab tests can be done within an hour.
"We work very hard to make sure that the answers that we give are accurate, and that takes time," said Karnauchow. "It's a huge frustration to many of us that people do have this sort of notion that, well, in this day and age, science should have all the answers five minutes ago."
When specimens are delivered to the lab, they are sorted into glass vials and launched simultaneously on a three-pronged testing process. The most basic test involves growing whatever virus is contained in the sample inside a test tube ? an eight-day process that allows technologists to identify the microbe based on the way it grows. "This is the baseline test, but it's not necessarily the most sensitive," said Karnauchow. "It answers a very broad question, which is: Is there a respiratory virus in there?"
The second test ? a more sensitive screen that takes mere hours ? involves isolating a sample virus on a glass slide and incubating it with a antibodies from known flu viruses.
Under a microscope, a more common strain of flu virus will bind with the corresponding antibody and glow a fluorescent green, allowing them to rule out the H1N1 virus.
By far the most sensitive test involves molecular screening, in which the genetic sequence of the suspect virus is analysed to determine whether it's a known microbe. The molecular assays at the regional lab can pick up human and non-human strains of influenza A, which causes flu in birds and some mammals, as well as influenza B, which is known to infect only humans.
"It's the ultimate in sensitivity, sort of the reference test," said Karnauchow.
After those tests are conducted, any sample that tests negative for a known virus is labelled "non-typeable," raising the likelihood it could be the H1N1 flu virus. At that point, the suspect sample is forwarded to Toronto, where the main virology lab conducts another round of screening, this time specifically for the H1N1 virus.
While it's still unclear whether H1N1 will stabilize or develop into a global pandemic, Karnauchow said he and his staff are "well positioned" to cope with the extra caseload should the outbreak persist into the summer.
"Many of us, if not all, feel that it's a real privilege to be part of the solution," said Karnauchow. "People here are really knocking themselves out to make sure everything is done right."
CNS 5/16/09 15:42:30
Virus hunters in overdrive
By Pauline Tam, Canwest News ServiceMay 16, 2009
OTTAWA ? Since the outbreak of swine flu, glass test tubes filled with mucus on a swab have been arriving ? by the pair, half-dozen, sometimes three dozen a day ? at the Ottawa laboratory where Susan Laporte works.
"The first few weeks, I think some people were spending most of the day working on these specimens," said Laporte, a medical technologist.
At her covered work station, she dons a face shield, visor, mask, gloves and special protective lab coat before handling the potentially hazardous microbes in those test tubes.
Each one is a question that awaits an urgent answer: Does this "nasopharyngeal swab," collected from the nose and throat of a patient with flu symptoms, test positive for the common strains of influenza that are known to virologists?
If not, could this sample contain the new strain of the H1N1 virus that has swept the globe?
The process of elimination falls largely to Laporte and her colleagues at the regional virology lab based at the Children's Hospital of Eastern Ontario.
Since the start of the flu outbreak, many of the lab's technologists have taken turns working seven days a week to handle the extra volume of diagnostic tests.
"People are working overtime, for sure," said Tim Karnauchow, the virologist who runs the lab. "We've had to tell people, 'You must keep track of your hours,' because most of them are saying, 'No, this is my duty.' They're very dedicated staff."
Typically, during the spring months, about a dozen samples are sent to the lab to be tested for respiratory illnesses.
"What this year represents is a respiratory season that refuses to die," said Karnauchow.
Because so little is known about the biology of the H1N1 flu virus, the screening process, involving three separate tests that isolate and identify suspect viruses, is far more exhaustive than tests for more common types of respiratory illnesses.
It can take up to two weeks, from the time a sample arrives at the regional lab to when a final verdict is issued from Toronto, for results of the flu test to reach patients.
For the virus hunters at the regional lab, the extra workload from the H1N1-flu outbreak comes with an added challenge: To provide as speedy and accurate a test result as possible without cutting corners. In this task, they are fighting a public perception, popularized by the TV series, CSI, that complex lab tests can be done within an hour.
"We work very hard to make sure that the answers that we give are accurate, and that takes time," said Karnauchow. "It's a huge frustration to many of us that people do have this sort of notion that, well, in this day and age, science should have all the answers five minutes ago."
When specimens are delivered to the lab, they are sorted into glass vials and launched simultaneously on a three-pronged testing process. The most basic test involves growing whatever virus is contained in the sample inside a test tube ? an eight-day process that allows technologists to identify the microbe based on the way it grows. "This is the baseline test, but it's not necessarily the most sensitive," said Karnauchow. "It answers a very broad question, which is: Is there a respiratory virus in there?"
The second test ? a more sensitive screen that takes mere hours ? involves isolating a sample virus on a glass slide and incubating it with a antibodies from known flu viruses.
Under a microscope, a more common strain of flu virus will bind with the corresponding antibody and glow a fluorescent green, allowing them to rule out the H1N1 virus.
By far the most sensitive test involves molecular screening, in which the genetic sequence of the suspect virus is analysed to determine whether it's a known microbe. The molecular assays at the regional lab can pick up human and non-human strains of influenza A, which causes flu in birds and some mammals, as well as influenza B, which is known to infect only humans.
"It's the ultimate in sensitivity, sort of the reference test," said Karnauchow.
After those tests are conducted, any sample that tests negative for a known virus is labelled "non-typeable," raising the likelihood it could be the H1N1 flu virus. At that point, the suspect sample is forwarded to Toronto, where the main virology lab conducts another round of screening, this time specifically for the H1N1 virus.
While it's still unclear whether H1N1 will stabilize or develop into a global pandemic, Karnauchow said he and his staff are "well positioned" to cope with the extra caseload should the outbreak persist into the summer.
"Many of us, if not all, feel that it's a real privilege to be part of the solution," said Karnauchow. "People here are really knocking themselves out to make sure everything is done right."
CNS 5/16/09 15:42:30