A potentially serious influenza outbreak is causing news coverage and government action world-wide:
There is more useful information from WHO and the U.S. CDC:
There are now over a thousand cases in Mexico, with more than 80 deaths thought to be related to this peculiar new strain of H1N1 influenza-A. For some reason, the 20 cases reported in the U.S. seem to be relatively benign, with only one requiring hospitalization. The strain has been found to respond to treatment with available antiviral drugs. Response to the outbreak has been rapid—due in part to world-wide preparations for the potential outbreak of H5N1 several years ago.
I don’t quite understand why some countries seem to be restricting movement of pork products, since it seems that respiratory activity would be required for transmission.
The most detailed information I can find is, sort of ironically, on Wikipedia:
The article has a long list of serious scientific references, with detailed information about how these things work. It appears—I’m not an epidemiologist, but I play one on my weblog—that pigs function as cute little pink genetic engineering laboratories for viruses. This better explains the bizarre accounts in the regular news stories about the virus strain being a sort of Frankensteinian patch-job of human, avian, and swine viruses. Swine can host influenza viruses from all three groups, allowing free-wheeling genetic recombination among them. One of the listed articles [Interspecies and intraspecies transmission of triple reassortant H3N2 influenza A viruses] also covers hypotheses on the requirements for transmission of the viruses among species. Of course, one of the most alarming things about this new strain of swine influenza is that it is clearly capable of transmission among humans who have no contact with porkers at all.