At least two Utah laboratories were among those that received — and destroyed at the request of worldwide health experts — samples of an influenza virus very similar to one that killed millions half a century ago.

Kits containing influenza viruses that included a Type A subtype H2N2 virus similar to the one that caused the Asian Flu pandemic in 1957-1958 was sent to almost 5,000 laboratories in 18 countries to be used to test the labs' proficiency in typing flu strains. A lab in Canada realized what the virus was and contacted the World Health Organization, which urged the labs to destroy the samples because of the remote possibility they could trigger a global outbreak.

This H2N2 virus strain was removed from vaccinations in 1968, and anyone born after that would have little if any immunity to it in the unlikely event it got out, said Dave Mendenhall, bureau director for laboratory improvement of the Public Health Laboratory run by the state Department of Health.

That state laboratory and at least one other Wasatch Front lab, ARUP (Associated Regional and University Pathologists, Inc.) Laboratories, received and destroyed the samples as requested. It's not clear if other Utah labs received similar virus samples.

The College of American Pathologists (CAP) sent out most of the kits including the H2N2 for proficiency testing in November and February. While testing normally is done on "currently circulating viruses," Mendenhall said, "this was one from the archives."

He called it "rare that this happens."

The Centers for Disease Control and Prevention (CDC) said the virus was part of test kits prepared by Meridian Bioscience Inc., which makes kits for several groups that help labs demonstrate their proficiency. It had reportedly received the deadly strain from a "germ library" several years ago.

Although most of the samples were sent to American labs, some were also shipped to laboratories in Bermuda, Belgium, Brazil, Canada, Chile, France, Germany, Hong Kong, Israel, Italy, Japan, Lebanon, Mexico, the Republic of Korea, Saudi Arabia, Singapore and Taiwan.

A World Health Organization release said that the U.S. Department of Health and Human Services learned recently that other proficiency test kit makers have sent their own samples that contain H2N2 to other labs in the United States and the department is "taking steps to ensure the rapid destruction of this material."

The formal request went out to labs from the CAP last week at the request of the federal government. Another request was issued Tuesday. Mendenhall's lab had received word and destroyed the sample Monday by incinerating it in the autoclave.

"Most of the sample was actually already gone," he said, explaining that the process of testing for virus subtype leaves little behind. "We just finished off what was left on Monday."