A decade ago, labs around the world were placed in a similarly risky situation when unmarked vials containing a type of influenza virus that could have caused a flu pandemic were sent out in error.
Back then a blunder in an unidentified British Columbia lab brought the mistake to light, potentially preventing a disaster.
Both cases underscore how critical it is to have good systems for managing dangerous pathogens — and how easy it is for a serious problem to occur, says Dr. Mel Krajden of the British Columbia Centre for Disease Control.
"Clearly it just shows you that people can make very stupid mistakes even with theoretical oversight," says Krajden, associate medical director for the BCCDC's public health microbiology and reference laboratory.
"The fact that this has occurred illustrates that we have to be super, super careful when managing these kinds of agents."
In both cases the dangerous pathogens were contained in prepared kits laboratories use to test how good they are at detecting pathogens.
In the current case the U.S. Department of Defence has discovered that one of its facilities, Dugway Proving Ground in Utah, put live anthrax in a test kit it disseminated.
The anthrax, which was supposed to be inactivated — killed — was in unlabelled vials. (That's part of the test: Can your lab staff figure out what this contains?)
Initially it was thought the anthrax went to a small number of labs. But the more authorities investigate, the bigger the problem becomes. On Wednesday the U.S. Department of Defence acknowledged that more than four dozen laboratories in the U.S. and abroad were sent the faulty kits. And the investigation is not over.
Three of the kits came to Canada, with two going to a Department of National Defence facility in Suffield, Alta., and one to the National Microbiology Laboratory in Winnipeg. Federal officials said Tuesday none of the kits had been used in more than five years and all were in secure storage.
The earlier test kit debacle was bigger, and potentially much more serious a threat.
In April 2005 somewhere between 4,700 and 5,700 laboratories in 18 countries, including Canada, were told to destroy part of a proficiency test kit they received from the College of American Pathologists.
The problem: The kits contained a vial of an unspecified live influenza virus that labs were meant to try to identify. It was actually H2N2, which caused the 1957 pandemic known as the Asian flu.
The influenza A virus circulated for nine years and then disappeared when the virus responsible for the 1968 pandemic — H3N2 — displaced it.
Many people born before 1968 would have been infected by H2N2 and therefore would have some antibodies to protect against it. But anyone born after 1968 — in 2005 that meant anyone under age 36 or 37 — would have had no protection against the virus.
If someone working with the unlabelled virus had contracted H2N2 and transmitted it to others, the virus could have taken off and triggered a global wave of flu infections and deaths.
The head of the World Health Organization's global pandemic program said at the time that while the mistake had the potential to trigger a global health emergency, a number of bad breaks would have had to happen to trigger disaster.
But it was lab error that led to the discovery in the first place. A B.C. lab that had received one of the kits informed the national laboratory that someone in that province had tested positive for H2N2. The B.C. lab thought it had spotted the re-emergence of the virus.
Investigation at the time revealed that the H2N2 virus had not come from a patient. The patient's sample had been contaminated with virus from the vial in the proficiency kit.
"People who should know better make mistakes," Krajden says.
"So I think the concern is figuring out how you prevent this kind of stuff from occurring."