Reuters/AFP
The US Centres for Disease Control and Prevention (CDC) said yesterday that it had uncovered a new safety breach at its bioterror research laboratories involving dangerous avian flu, just as it was investigating the failures behind the potential exposure of researchers to live anthrax bacteria.
In its first findings from an internal probe into the anthrax incident last month, the CDC said multiple failures by individual scientists and a lack of agency-wide safety policies had led to the potential exposure of more than 80 lab workers to the dangerous bacteria at its campus in Atlanta.
During the probe, investigators also discovered a previously unreported incident: Workers at a high-security CDC lab sent samples containing a dangerous strain of bird flu to counterparts at the US Department of Agriculture in March.
“Earlier this year a culture of non-pathogenic avian influenza was unintentionally cross-contaminated at the CDC influenza laboratory with the highly pathogenic H5N1 strain of influenza and shipped to a BSL-3 select-agent laboratory operated by the United States Department of Agriculture (USDA),” the CDC said in a statement.
The H5N1 bird flu is highly contagious and has killed about 60% of humans who been sickened by it.
It first infected humans in 1997 during a poultry outbreak in Hong Kong, and became widespread in 2003 and 2004.
The CDC’s director, Dr Thomas Frieden, said the type of H5N1 was not the exact same type as the one that spread in China, but “it is one of the ones that does concern us because it can be quite deadly both for poultry and for people”.
The other type of flu involved was H9N2, he said.
Mishandling of avian flu could have far graver consequences for the public than with anthrax.
So far, no one has been found to have been infected due to either the avian flu or anthrax incidents.
Frieden called the bird flu incident “the most distressing” because it occurred six weeks ago, but was not reported to senior agency leadership.
“I learned about it less than 48 hours ago,” Frieden told reporters.
“These events should never have happened,” he said, adding that the events likely “have people questioning government”.
“Frankly, I’m angry about it,” he said.
“Everything we have looked at strongly suggests that there was no exposure of anyone to influenza,” said Frieden.
Although the report identifies failures to adhere to biosafety protocols at multiple levels – including scientists working with anthrax who were not familiar with relevant studies on the kind of research they were conducting – it does not name any of the responsible individuals and the CDC has not said how any will be disciplined, if at all.
The agency said it is suspending any transfers inside or outside the agency of biological materials, including infectious agents and even inactivated specimens, from high-biosecurity labs.
The moratorium will remain in place pending review by an advisory committee.
The CDC influenza laboratory is also now closed and will not reopen until adequate procedures are put in place, the CDC said.
In reconstructing the anthrax incident, investigators found that scientists working with the deadly bacteria failed to follow an approved, written study plan that met all laboratory safety requirements.
The scientists lacked standard operating procedures to document when microbes are properly inactivated.
In the anthrax case, scientists working in a high-biosecurity laboratory sent samples that they believed had been inactivated to a lower-biosecurity lab; it turned out that the samples had not been properly inactivated and thus could have infected people.
The CDC laboratories also lacked proper oversight of scientists performing work with dangerous pathogens, the report found.
Once the CDC officials were alerted that live anthrax may have been transferred from the high-security lab, their response also fell short.
For instance, CDC scientists in other labs first learned of the event not through official communication but “by witnessing CDC closing and/or decontaminating laboratories”, the report said.
To prevent future mishaps with dangerous organisms, the CDC is creating a “lead laboratory science” position to be accountable for safety and setting up an external advisory committee on biosafety.