although I continued reading about this flu, and it does say that the virus strain is traveling from birds to other things to humans. Pandemic? Maybe, but still there's nothing that says the 1918 version was avian:
From 1998 to 2001 the (avian flu) virus went through multiple reassortments and moved back to domestic birds, spreading almost unnoticed in Chinese chicken flocks. It continued to evolve at high speed: 17 more reassortments occurred, and in January 2003 the "Z" virus emerged, a mutant powerhouse that had become tougher, capable of withstanding a wider range of environmental challenges. The Z virus spread to Vietnam and Thailand, where it evolved further, becoming resistant to one of the two classes of antiflu drugs, known as amantadines, or M2-inhibitors.
In early 2004, it became supervirulent and capable of killing a broad range of species, including rodents and humans. That permutation of the virus was dubbed "Z+." In the first three weeks of January 2004, Z+ killed 11 million chickens in Vietnam and Thailand. By April 2004, 120 million chickens in Asia had died of flu or been exterminated to slow the influenza brushfire. The avian epidemic stopped for a while, but in July another 1 million chickens died from the disease. The Z+ virus was causing massive internal bleeding in the birds. By the beginning of 2005, with chickens dying and customers shying away from what remained, the Asian poultry industry had lost nearly $15 billion.
By April 2005, the H5N1 virus had also moved to pigs. Scientists isolated the disease from swine in a part of Indonesia where pigs are raised underneath elevated wood-slatted platforms that house chickens. Less rigorous investigations had previously indicated that pigs in China and Vietnam may also have been infected by H5N1 influenza. The discovery in Indonesia provided disturbing evidence that the virus was infecting mammals, although it was not yet known how widely the swine disease had spread or how lethal it was for the animals.
HARD TO KILL
Over the course of this brief but rapid evolution, the H5N1 virus developed in ways unprecedented in influenza research. It is not only incredibly deadly but also incredibly difficult to contain. The virus apparently now has the ability to survive in chicken feces and the meat of dead animals, despite the lack of blood flow and living cells; raw chicken meat fed to tigers in Thailand zoos resulted in the deaths of 147 out of a total of 418. The virus has also found ways to vastly increase the range of species it can infect and kill. Most strains of influenza are not lethal in lab mice, but Z+ is lethal in 100 percent of them. It even kills the very types of wild migratory birds that normally host influenza strains harmlessly. Yet domestic ducks, for unknown reasons, carry the virus without a problem, which may explain where Z+ hides between outbreaks among chickens. |
