CDC and WHO recommend that sample panels of influenza A/H2N2 be destroyed

 

CDC, HHS, and the World Health Organization are working with the College of American Pathologists (CAP) and other providers of proficiency testing panels (see below) to ensure that influenza A/H2N2 samples sent to U.S. laboratories and laboratories in 17 other countries are destroyed immediately. Information sent with these proficiency testing panels did not indicate that influenza A/H2N2 samples were included. The A/H2N2 samples sent out are similar to the A/H2N2 viruses that circulated in humans in 1957 at the beginning of the Asian influenza pandemic. Influenza A/H2N2 viruses continued to circulate widely in the human population until they disappeared upon the introduction of influenza A/H3N2 viruses during the 1968 Hong Kong influenza pandemic. Therefore, persons born after 1968 have no or only limited immunity against A/H2N2 strains. To date, no influenza A/H2N2 human cases among laboratory workers have been associated with distribution or handling of these proficiency testing panels. However, because of the potential risk associated with this particular strain, laboratories have been advised to immediately autoclave or incinerate and treat as potentially infectious and hazardous all materials retained or derived from these panels.

CAP, the American Association of Bioanalysts, the American College of Family Physicians and the American College of Physician Services all sent proficiency testing surveys containing one or more samples of A/H2N2 to approximately 6,500 labs in the United States. Proficiency testing panels containing A/H2N2 samples were also sent to laboratories in Belgium, Bermuda, Brazil, Canada, Chile, France, Germany, Hong Kong, Israel, Italy, Japan, Lebanon, Mexico, Saudi Arabia, Singapore, South Korea and Taiwan. The World Health Organization has informed the Ministries of Health in these countries.

Although there is low risk of infection of laboratory workers who use proper biosafety precautions, and historic data suggest that it is unlikely that a laboratory worker will have been infected, destruction of the samples is strongly recommended. Instructions for appropriate destruction of the A/H2N2 samples were distributed to the laboratories that received A/H2N2 samples. 

CDC remains in close communication with WHO, as well as the College of American Pathologists and other providers of proficiency testing panels, about the identification and destruction of the H2N2 panels of concern and will provide additional information as it becomes available.