Flu season has arrived, and it’s sure to be a nuisance—but will it be interesting? This year, the CDC is keeping a keen eye on three novel swine flus that have infected humans. This pig-to-human transmission is noteworthy in itself, but there’s more: two of the three swine flu viruses have taken on genetic material from the 2009 H1N1 virus, in a process known as reassortment.
Confirming the onset of flu season is a February 10 Flu Report by the CDC; the arrival of flu season is nothing remarkable. But since August, the CDC has reported three novel influenza A virus variants (H3N2v, H1N1v, H2N2v) that have infected humans in the U.S., for a total of 14 cases. (Twelve of the 14 cases are H3N2v.) All three viruses originated in swine herds, and CDC has labeled the infection of humans with these swine flus as “rare events.” On December 9, the CDC was “taking this situation very seriously.” Read More >
Dr. Margaret Chan
The World Health Organization (WHO) has decided to raise the level of influenza pademica lert from phase 5 to phase 6, the highest level. The level was heightened, according to WHO, based on “available evidence and expert assessments of the evidence, the scientific criteria for an influenza pandemic have been met.”
“The world is now at the start of the 2009 influenza pandemic,” WGO Director-General Dr. Margaret Chan said in a statement to the press today. “We are in the earliest days of the pandemic. The virus is spreading under a close and careful watch. No previous pandemic has been detected so early or watched so closely, in real-time, right at the very beginning.”
Dr. Chan emphasized that many, but not all, severe cases have occurred in people with underlying chronic conditions. “At the same time, it is important to note that around one third to half of the severe and fatal infections are occurring in previously healthy young and middle-aged people.”
Despite the heightened level, WHO says it continues to recommend no travel restrictions or border closures.
The ongoing outbreak of Swine Flu / novel influenza A (H1N1) highlights one of the many serious public health risks that industrial food animal production (IFAP) poses on a global scale. It is known that pigs are “mixing vessels” for influenza viruses (for swine, avian and human flu), and it is believed that the last two flu pandemics, in 1957 and 1968, broke out when avian flu and human flu viruses mixed genetically with pig viruses to create a new flu virus that was transferred back to people. It has also been suggested that the 1918 Spanish Flu originated from pigs (Chasing the Fickle Swine Flu, March 7, 2003, Science).
Insufficient evidence is available to definitively determine whether the current swine flu outbreak originated from IFAP swine operations. However, through analyses of genome sequences generated by the Centers for Disease Control and Prevention (CDC) from current virus isolates, Columbia University researchers have proposed two swine-related genetic ancestors of the current virus. Of these, one that accounts for six of the eight genetic segments of the virus has been identified as the H3N2 virus, a triple reassortment of swine, avian and human virus first isolated in pigs on a North Carolina swine operation in August of 1998. (Evolution of Swine H3N2 Influenza Viruses in the United States, Journal of Virology, September 2000) The other two segments are believed to be from swine viruses of Eurasian origin (Trifonov, 2009). Read More >
According to the New York Times, health officials in Mexico have toured a million-pig hog farm in Perote, in Veracruz State searching for the original source of the swine flue outbreak . The plant is half-owned by Smithfield Foods, an American company and the world’s largest pork producer.
“Last year the Pew Commission on Industrial Farm Animal Production warned that hog farms could become breeding grounds for new strains of the flu,” said a report on last night’s CBS Evening News. Bob Martin, former executive director of the Pew Commission, told CBS, “The warm conditions and the close proximity of animals being able to pass viruses back and forth and to the human workers is the situation ripe for the development of a novel virus.”
This morning, the death toll from the outbreak was raised to 152, and the World Health Organization voted to raise its global pandemic flu alert level. More information on the swine flu can be found on the Livable Future Blog.
The World Health Organization is poised to raise the pandemic threat level as a deadly strain of the swine virus shows no sign of slowing down, according to a latest Reuters report. The New York Times reports that the number of people killed by the virus has climbed to 149 in Mexico and 8 of the 20 confirmed cases in the U.S. were diagnosed in New York City.
Reuters says the change in threat levels would indicate that the virus has mutated to the point that it is being transmitted from person to person more easily. According to an earlier Reuters report the CDC’s early analysis determined the virus strain, which is designated H1N1 (similar to the “Spanish Flu” which killed tens of millions of people in the early 20th Century) contains DNA from swine, human and avian viruses.
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