The problem, it seems, is that the test kit contained the 1957 pandemic flu strain, which no one has been vaccinated against since 1968. The story reports that, "It was not immediately clear why the 1957 pandemic strain, which killed between 1 million and 4 million people -- was in the proficiency test kits routinely sent to labs." The story continues;
Most of the samples were sent starting last year at the request of the College of American Pathologists, which helps labs do proficiency testing. The last shipments were sent out in February.
Dr. Jared Schwartz, an official with the pathology college, said a private company, Meridian Bioscience Inc. of Cincinnati, Ohio, is paid to prepare the samples. The firm was told to pick an influenza A sample and chose from its stockpile the deadly 1957 H2N2 strain.
Regardless of the wisdom of this choice, it is interesting that it was caught at all -- one of the labs correctly identified the 1957 strain. That bodes well for infectious disease surveillance, but note that this was a test kit sent to the labs, not an environmental sample that they had to test completely blind.
Note also that the strain is now out in the world again, and could thus be kept as a potential weapon. Most of the kits were shipped to labs in the US, and the College of American Pathologists has requested confirmation in writing that all the test kits have been incinerated. Which is great. Except that the bug is still now out in the world. Even if this was an accident -- especially if this was an accident -- the incident highlights how ill prepared the global community is for biological surprises.
UPDATE (14 April 05): Effect Measure has nice coverage of this incident.