Flu Strain Samples Remain at Large

CDC Director Julie L. Gerberding said tougher safety precautions will be expedited. (John Bazemore -- AP)

Schwartz, at the College of Pathologists, agreed: "If you are going to be shipping products to other countries, it is incumbent upon you to understand the regulations in those countries."

Canadian authorities said they are conducting blood tests on lab workers potentially exposed to the virus and monitoring for symptoms such as high fevers, coughs and muscle aches.

"We are double-checking to make sure there has been no secondary spread from these samples," said David Butler-Jones, Canada's chief public health officer.

Flu experts said the case is a sobering reminder of how easily mistakes can occur with the potential to unleash dangerous pathogens.

"This is an important wake-up call for all of us," said William Schaffner, a flu expert at Vanderbilt University. "It reminds all of us who work in laboratories and run them that laboratory safety has got to be a priority."

The fact that the error occurred at a company involved in testing the proficiency of labs was particularly surprising.

"The irony is that it was part of a routine proficiency test. Here we have the very people involved in a quality-assurance exercise that actually went awry," he said.

The government has failed to keep a close inventory on dangerous pathogens, Schaffner added.

"There are thousands of laboratories -- government laboratories, academic laboratories, commercial laboratories. All of them have pathogens -- viral, bacterial, whatever. We know relatively little about which bugs are in which laboratories," he said.