Influenza Update December 2011

The local influenza activity has been very low (so far). Of note is that there is a new - as in novel - flu virus that's reared it's ugly head in the US.

From August to December the CDC reports that there have been 12 human infections with influenza A (H3N2)v with the M gene from the A(H1N1)pdm09 virus. This is significant because this is a new mix of swine virus. 11 of the 12 cases are in children and 6 had no exposure to swine. The good news is that all have recovered fully.
Surveillance for swine influenza is overseen by USDA that started in 2009. So far they've found 150 isolates, of these 30 have this A(H3N2) and 8 of these have the M gene from flu A(H1N1).
Human infections with influenza circulating in swine are very rare. Swine make perfect mixing vessels of all types of influenza virus. Because this is a newly identified combination of genes it's hard to tell where this is going. Hopefully nowhere.

Updated information and guidance documents related to A(H3N2)v viruses are available online from CDC at http://www.cdc.gov/flu/swineflu/influenza-variant-viruses.htm.