Standardization of Terminology for the Variant A(H3N2) Virus Recently Infecting Humans

January 18, 2012 — 

FAO, OIE and WHO continue working closely together to address influenza issues related to public health and animal health.

Since July 2011, twelve human cases of infection with a variant influenza A(H3N2) virus have been detected in the United States. To date, no report has been received from elsewhere in the world. This virus has different virological characteristics from current circulating seasonal influenza viruses in humans, and has a new gene constellation: 7 genes from the triple reassortant A(H3N2) viruses known to have been circulating in pigs in the North America and the M gene from an A(H1N1)pdm09 virus, a seasonal virus currently circulating in humans.

In order to improve communications and avoid confusion, FAO, OIE and WHO have established a working group of experts to standardize the terminology for variant influenza viruses. The joint recommendation for the above mentioned A(H3N2) virus is: A(H3N2)v , where “v” stands for “variant”.

An example of use of the terminology: "Sporadic human cases of infection with a variant influenza A(H3N2) virus A(H3N2)v have been reported in the USA. The A(H3N2)v virus is different from seasonal viruses currently circulating in humans."

[Editor's note: AASV has been working in collaboration with NPB and NPPC to raise awareness of the impact on swine producers of influenza nomenclature that uses terms such as "swine-origin". This nomenclature is confusing and misleading to consumers. The USDA and CDC have been very receptive to discussions associated with trying to find alternative terminology that remains scientifically accurate and descriptive but is less harmful to livestock producers and more accurately promotes educational outreach efforts to raise awareness among the public. We welcome the domestic and international recognition of these challenges and the efforts being undertaken to standardize influenza terminology utilized in lay publications.]

Source: FAO News Release, December 23, 2011 (Joint FAO, OIE, WHO announcement)