Labs told to destroy killer virus
(CNN) -- The World Health Organization has told laboratories to immediately destroy samples of a flu virus after a Canadian lab identified it as a strain that triggered a 1957 pandemic.
The order to destroy the vials was sparked by a slim, but real risk that the samples could spark a global flu epidemic.
Five thousand vials of the 1957 strain of the "Asian flu" virus were sent out to more than 3,700 labs in 18 nations from September until early April.
That particular strain killed more than one million people, including about 70,000 in the United States, in a 1957-58 pandemic.
Because the virus has not been included in flu vaccines since 1968, anyone born after that would not be immune to that strain.
Virus samples are distributed to laboratories so lab workers can test their ability to identify samples, but they are normally strains in current or recent circulation.
WHO influenza chief Klaus Stohr told The Associated Press the risk is relatively low that a lab worker will get sick, but there was a concern because of the large number of labs that received it.
"If someone does get infected, the risk of severe illness is high and this virus has shown to be fully transmissible."
It is unclear why the strain was in the test kits sent out to the labs, but AP quoted WHO's Stohr as saying the decision was "unwise" and unfortunate.
The U.S. Centers for Disease Control agrees there is little risk to the public from the virus.
CDC spokesman Dan Rutz said there have been no cases of illness reported and insisted there is "no public health threat."
The virus, known as influenza A/H2N2, was distributed by the College of American Pathologists (CAP), which obtained the samples from a Cincinnati-based vendor.
All but 61 of the 3,700 labs the samples were sent to places in the United States or Canada.
All samples should be destroyed within a day or two, said Dr. Jared Schwartz, a spokesman for the College of American Pathologists. The virus can be killed either by incineration or by chemicals, he said.
"We under no circumstances would ever vouch for an H2N2 to be sent out," Schwartz said.
Schwartz said his organization requested samples of an influenza A virus with a biological safety level of 2 -- meaning it can be handled safely under standard laboratory conditions -- from the vendor, Meridian Bioscience.
The 1957 flu virus has for years been a level 2 virus, but many countries have upgraded it to a biosafety level of 3 because so many people have no immunity to it, the AP reported.
Schwartz said it was not clear whether the company knew the samples were of the H2N2 strain.
"According to their records, they did not believe this was a highly pathogenic virus," he said.
There was no immediate comment from Meridian Bioscience, but Schwartz said his organization was told the vendor received the virus from another company in 2000.
Schwartz said his organization requested "an influenza A, period," and the vendor's paperwork indicated that is what they had.
"Most laboratories would just say it's an influenza A and destroy the sample," he said.
But a laboratory in Winnipeg, Manitoba, went further, identified it as the 1957 pandemic strain and notified the Centers for Disease Control, he said.
Schwartz said his organization will ask the CDC to approve strains sent out for testing in the future, and samples will be limited to pathogens covered by current vaccines.
"This is the first time, thank God, that we have had, in any of our proficiency testing, issues focused on as a potential problem," he said.
"It's regrettable, and a lot of communication needs to be improved to be sure that this doesn't happen again. And we're going to be working with the CDC to make sure of that."
CNN Medical Producer Miriam Falco contributed to this report
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Associated Press contributed to this report.
