A US government laboratory mistakenly mixed a common strain of the flu with a dangerous, deadly type of avian influenza and shipped it to another lab, authorities said on Friday.
The latest news followed admissions of mishandled anthrax and forgotten smallpox vials at separate US government labs and raised new concerns about the safety of dangerous agents that could be used as weapons for bioterrorism.
No one was endangered by the mixed flu strain, said US Centers for Disease Control (CDC) and Prevention director Tom Frieden, who nevertheless said he was “astonished” that protocols could have been violated in that way.
“Everything we have looked at strongly suggests that there was no exposure of anyone to influenza,” Frieden at a press briefing.
He said he had lost sleep since learning of the flu mix-up on Wednesday, six weeks after it occurred.
Frieden said he has issued a moratorium on the transfer of any biological samples, including infectious agents, within or outside the agency until an investigation is complete.
He also called for appropriate disciplinary action for staff who knowingly violated protocol or failed to report a lab incident.
The center said it learned of the flu mix-up while finalizing a report on the anthrax incident on June 5, which it concluded was very unlikely to have put workers at risk, though about 80 people were initially considered vulnerable.
“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 US Department of Agriculture,” the center said in a statement.
The lab is closed until better safety measures can be enforced and an investigation is underway.
“For me personally, this is the most distressing,” Frieden said of the mix-up on May 23.
The H5N1 strain of bird flu is highly contagious and has killed about 60 percent of humans infected by it.
Frieden said the H5N1 in the mix-up was not the exact same as the one that spread in China in 2003 and 2004, 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 influenza strain involved was H9N2, he said.
The incidents may raise further concerns among opponents of studies known as “gain of function” research, in which scientists manipulate flu strains to find out how they can spread more easily and how to better vaccinate against them.
The agency has also completed initial testing on the six apparently forgotten vials of smallpox found in a US Food and Drug Administration lab at the National Institutes of Health, two of which had viable smallpox in them, Frieden said.
After scientists complete tests, they will destroy the samples in view of WHO officials, he said.
“That is what should have been done a couple of decades ago,” Frieden said. “Whoever created these vials did not do so out of malice.”