April 13, 2005
H2N2 influenza virus, similar to the 1957-58 pandemic, mistakenly sent for lab testing in 18 nations
Today multiple media reports and statements on the WHO and CDC websites confirmed that at least one US laboratory sent laboratory proficiency testing samples that contained the H2N2 influenza virus, similar to the one that caused the 1957-58 human pandemic, to more than 3,747 labs in 18 nations. These countries included: Singapore, Hong Kong, Taiwan, Japan, The Republic of Korea, Saudi Arabia, Israel, Lebanon, France, Germany, Italy, Belgium, Chile, Brazil, Mexico, Canada, Bermuda, and the USA. Most of the samples went to labs in the US and Canada, with 61 of the 3,747 labs located in the other 16 nations.
The shipments that included the H2N2 virus were made between October 2004 and February 2005 as part of a routine panel of influenza A and B viruses distributed by the College of American Pathologists to be used by labs for proficiency testing and lab quality control. Normally, H3N2 and H1N1 influenza A viruses are distributed for lab proficiency testing, according to the WHO.
The WHO reported on their website, in a document dated April 12, 2005, that the US Department of Health and Human Services (HHS) “has recently learnt that other proficiency testing providers have sent additional H2N2 samples to further laboratories in the USA. HHS is taking steps to ensure the rapid destruction of this material.”
A large debt of gratitude is owed to the Canadian scientists who first identified the presence of this H2N2 influenza A virus. On March 26, 2005 the Public Health Agency of Canada (PHC) notified the WHO of this H2N2 virus, similar to the virus found at the beginning of the 1957 human pandemic. They then worked to identify the source of this H2N2 virus, and found that it came from the American College of Pathologists panel of lab proficiency samples. On April 8 the WHO, HHS, and CDC were notified by Canada of the source of the virus.
Fortunately, not a single human infection has been found as a result of this H2N2 virus having been shipped to over 3, 700 labs.
The H2N2 virus circulated in the human population from 1957-1968. Then, it went out of circulation when the H3N2 influenza pandemic hit in 1968. Thus, importantly, persons born after 1968 have little or no immunity to H2N2 influenza. Moreover, there is no vaccine currently available against this H2N2 virus.
The theoretical potential to trigger a new pandemic due to H2N2 influenza is evident, although the current risk to the public is considered low by the WHO. Another theoretical risk is that a severe pandemic could be triggered if this H2N2 virus, capable already of spreading in a sustained manner from person-to-person, combined with another virus such as the H5N1 avian influenza virus that has killed 50/80 laboratory-confirmed cases in Asia in the past 15 months.
On April 1, 2005 US President Bush issued an Executive Order amending the prior order of April 4, 2003 (during SARS) regarding quarantinable communicable diseases to include “Influenza caused by novel or reemergent influenza viruses that are causing, or have the potential to cause, a pandemic” (source: www.cdc.gov/ncidod/dq/).
International vigilance is warranted to certify that all laboratories worldwide that received this H2N2 virus destroy all samples, and that outbreaks of influenza A are tested for H2N2, as well as H5N1, if they are not identified as the usual H3N2 or H1N1 influenza A viruses. Review and optimization of laboratory biosafety protocols for handling influenza virus samples to protect lab workers (and their families and other contacts) is warranted on a global basis. In addition, safeguards to ensure that no further errors regarding shipment of routine proficiency testing samples containing H2N2 influenza virus are needed.
Daniel R. Lucey, MD, MPH
Center for Biologic Counterterrorism and Emerging Diseases
Washington Hospital Center
Department of Microbiology and Immunology
Georgetown University School of Medicine