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  • Scientists to probe Mexican town's flu mystery

    Scientists to probe Mexican town's flu mystery

    By MARGIE MASON and ALEXANDRA OLSON, Associated Press Writers – 28 mins ago

    MEXICO CITY – No one has identified ground zero in the swine flu epidemic. Just where or when the new strain of influenza first jumped from a pig and began infecting people is a scientific mystery — one that a group of flu detectives is determined to solve.

    Scientists are returning next week to La Gloria, a pig-farming village in the Veracruz mountains where Mexico's earliest confirmed case of swine flu was identified. They hope to learn where the epidemic began by taking fresh blood samples from villagers and pigs, and looking for antibodies that could suggest exposure to previous swine flu infections.

    Some experts say it's pointless to worry about what happened in La Gloria now that the swine flu virus has spread around the world. But others argue that a thorough investigation could be key to preventing future epidemics.

    And Mexico has another reason to care: If it can somehow rule out the possibility that La Gloria's pigs infected humans, then it can tell the world it wasn't to blame for the epidemic — that the never-before-seen H1N1 swine flu virus came from somewhere else.

    More than half of La Gloria's 3,000 residents fell ill with flu symptoms weeks before the new virus was identified. Many found it hard to breathe, burned with fever and ached all over. About 450 of the sickest residents were diagnosed with acute respiratory infections and sent home with antibiotics and masks.

    Mexican health officials initially downplayed the outbreak, saying the villagers suffered from regular flu. A 5-year-old boy was the only confirmed swine flu case among 43 villagers whose mucous samples were taken in early April. By then, most other villagers had recovered, and the virus was gone from their systems.

    But some disease experts suspect swine flu was circulating more widely in La Gloria.

    "I cannot understand it. I could almost bet that there were more infections related to this virus" in La Gloria, Dr. Carlos Arias told The Associated Press. Arias is leading a group of flu detectives from the Biotechnology Institute and the veterinary school of the National Autonomous University of Mexico back to the village at the invitation of the Veracruz state government.

    Pigs — like people — get the flu, usually over the winter months. This new swine flu virus is unusual in that it also has infected humans and at this point has become a full-blown human flu.

    La Gloria's villagers believe they were sickened by the surrounding commercial pig farms, which they accuse of polluting their air and water with pig waste. But the pork industry wants a closer look at pigs raised in the villagers' backyards, which may not have been vaccinated or cared for with swine flu-prevention in mind.

    Arias said his team also will examine environmental and sanitary conditions in homes where pigs are raised, and make recommendations to the Veracruz government aimed at reducing the potential for human infections.

    "It would be very interesting to look at the evolution of this virus and where or how easily the virus originates, reassorts and reassociates genes in an environment like La Gloria," he said. "But also maybe that would mean that we would have to change the conditions of farming animals."

    Virginia-based Smithfield Foods, Inc., which jointly owns 72 farms in the surrounding La Gloria, said it carefully vaccinates its herd, and has found no signs or symptoms of any kind of swine flu in its herd or its employees anywhere in Mexico.

    Enrique Sanchez, a top official in Mexico's Agriculture Department, which has defended the nation's pork exporters from swine flu-inspired trade bans, said no sign of the new strain was found in mucous samples taken April 30 from pigs at Smithfield's Mexican subsidiary, Granjas Carroll.

    But those samples were taken weeks after most villagers had recovered from their infections — perhaps too late for the virus to show up. Even after a person or pig recovers, however, antibodies remain in their blood, evidence of the body's immune response to the infection. And if swine flu antibodies are teased out of pigs in La Gloria, it would suggest, though not definitely prove, that the virus jumped from swine to humans there, Arias said.

    Other scientists believe the new strain could have been circulating in humans long before it reached La Gloria. The new strain's ancestry has ties to a pig farm in North Carolina where in 1998, scientists discovered that pig, bird and human viruses had combined in pigs to form a new strain of swine flu that also infected a handful of humans.

    Most of the current strain can be traced to that combination, about 10,000 generations of the virus ago. At some point along the way, it combined with other flu strains and jumped back into humans — just when and where exactly may never be known, CDC officials have said.

    A federal government research team also plans to return to La Gloria, to review health records, interview residents and search for antibodies. The boy's positive test result "has to lead us to go back and look closer," said Dr. Ethel Palacios, deputy director of Mexico's swine flu monitoring effort.

    Labs capable of testing for the new swine flu strain have focused on helping sick people rather than find scientific evidence pointing to the starting point of the epidemic, which has now sickened more than 10,000 people around the world and killed 80, mostly in Mexico.

    At this point, learning the source won't change how the world must respond to this epidemic, said Dr. Sylvie Briand of the World Health Organization's global influenza program in Geneva.

    Still, it rankles Mexico that some researchers have assumed La Gloria was a starting point, based on the unusual number of lung infections there just before swine flu was identified. In a Science journal study last week, the WHO Rapid Pandemic Assessment Collaboration made this assumption for mathematical models suggesting the epidemic had spread to thousands of people across Mexico before the virus had a name.

    Co-author Christophe Fraser concedes his team has no evidence La Gloria was ground zero, but he finds Mexico's assertion that seasonal influenza was solely to blame unlikely.

    "The attack rate in the outbreak (in La Gloria) is inconsistent with seasonal influenza," Fraser, a scientist with the Department of Infectious Disease Epidemiology at Imperial College London, wrote in an e-mail to AP. "It is not impossible, though, that multiple viruses were co-circulating."

    Finding answers won't be easy: Time has passed and if people or pigs have been infected by similar flu strains in the past, their antibodies could lead to false positives, said Alfredo Torres, an assistant professor at the University of Texas Medical Branch.

    "There may not be any footprints to look at," said Tom Ksiazek, director of the university's National Biodefense Training Center, who with Torres is serving as a consultant to the Veracruz state government. Ksiazek, who has investigated outbreaks of Ebola virus and SARS, suspects villagers were getting infected from each other, not pigs.

    Meanwhile, Arias is frustrated that the government has not provided details about its tests on humans and pigs.

    "The information is not been distributed freely," he said. "We cannot work with only assumptions and rumors. We need solid data."

  • #2
    Re: Scientists to probe Mexican town's flu mystery

    still no mention of any possible other origin (4115,4487),
    possible transmission from the environment.


    ------------------------------------------------

    Alfredo Torres, an assistant professor at the University of Texas Medical Branch
    http://www.utmb.edu/pathology/profiles/?user=altorres

    Tom Ksiazek, director of the university's National Biodefense Training Center, who with
    Torres is serving as a consultant to the Veracruz state government
    http://www.csiro.au/events/Snowdon-Lecture-2009.html

    Dr. Carlos Arias is leading a group of flu detectives from the Biotechnology Institute
    and the veterinary school of the National Autonomous University of Mexico
    http://en.wikipedia.org/wiki/Carlos_Arias_Ortiz
    http://www.ibt.unam.mx/server/PRG.ba...ulum,par:arias

    Enrique Sanchez, a top official in Mexico's Agriculture Department, which has defended the
    nation's pork exporters from swine flu-inspired trade ban

    Dr. Ethel Palacios, deputy director of Mexico's swine flu monitoring effort.

    Co-author Christophe Fraser

    -----------------------------------------
    I'm interested in expert panflu damage estimates
    my current links: [url]http://bit.ly/hFI7H[/url] ILI-charts: [url]http://bit.ly/CcRgT[/url]

    Comment


    • #3
      Re: Scientists to probe Mexican town's flu mystery

      http://www.fosters.com/apps/pbcs.dll...865/-1/SANNEWS
      Monday, June 29, 2009
      Scientists are returning next week to La Gloria,
      They hope to learn where the epidemic began by taking fresh blood samples from villagers and pigs, and looking for antibodies that could suggest exposure to previous swine flu infections.
      I'm interested in expert panflu damage estimates
      my current links: [url]http://bit.ly/hFI7H[/url] ILI-charts: [url]http://bit.ly/CcRgT[/url]

      Comment


      • #4
        Re: Scientists to probe Mexican town's flu mystery

        An article in Mother Earth News links to a 2006 profile of Smithfield in the Rolling Stone.

        Brief recent article in Mother Earth News
        http://www.motherearthnews.com/Happy...ory-Farms.aspx

        The 2006 Rolling Stone article is quite lengthy and disturbing.


        Boss Hog
        America's top pork producer churns out a sea of waste that has destroyed rivers, killed millions of fish and generated one of the largest fines in EPA history. Welcome to the dark side of the other white meat.

        JEFF TIETZ
        Posted Dec 14, 2006 8:53 AM

        Article at
        http://www.rollingstone.com/politics...st_polluters/1
        "There's a chance peace will come in your life - please buy one" - Melanie Safka
        "The greatest way to live with honor in this world is to be what we pretend to be" - Socrates

        Comment


        • #5
          Re: Scientists to probe Mexican town's flu mystery

          This NYT article picks up in Romania where the Rolling Stones one leaves off. Articles like these make a person realize just how big Smithfield is and how easy it is for them to get what they want. Proving their pigs were free of disease, whether they were or not, would likely be very, very easy.

          A U.S. Giant Transforms Eastern Europe
          [snips]
          In less than five years, Smithfield enlisted politicians in Poland and Romania, tapped into hefty European Union farm subsidies and fended off local opposition groups to create a conglomerate of feed mills, slaughterhouses and climate-controlled barns housing thousands of hogs.

          It moved with such speed that sometimes it failed to secure environmental permits or inform the authorities about pig deaths — lapses that emerged after swine fever swept through three Romanian hog compounds in 2007, two of which were operating without permits. Some 67,000 hogs died or were destroyed, with infected and healthy pigs shot to stanch the spread.

          http://www.nytimes.com/2009/05/06/wo...d&st=cse&scp=1
          The salvage of human life ought to be placed above barter and exchange ~ Louis Harris, 1918

          Comment


          • #6
            Re: Scientists to probe Mexican town's flu mystery

            Now then, was there, once upon a time, any proximate geographical relationship between Smithfield (swine) and Bernard Matthews (turkey) in Hungary close to the border with Romania? Or was there a direct wild bird migration route between the two? Not speculation, just asking.

            Comment


            • #7
              Re: Scientists to probe Mexican town's flu mystery

              Those 2007 deaths were form CSF, which is: ssRNA positive-strand viruses, no DNA stage; Flaviviridae; Pestivirus

              ProMed report of initial outbreak:
              http://www.promedmail.org/pls/otn/f?...AIL_ID:X,38749

              But since the initial outbreak was in Cenei, Romania, it's worth inquiring.

              .
              "The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller Foundation

              Comment


              • #8
                Re: Scientists to probe Mexican town's flu mystery

                http://noticiasaxoncomunicacion.net/...ino-de-la-uab/


                Swine flu: scientists dogmas and truths
                GERARD MARTÍN GERARD MARTIN
                gerard.martin@cresa.uab.cat gerard.martin @ cresa.uab.cat

                The swine flu since its first detection until now, has been described as a clinical infection that causes acute respiratory signs characterized by high fever, prostration, abortions and anorexia. Another typical feature of the disease reported a high transmissibility, affecting the vast majority of animals on the farm causing an explosive epidemic with an appearance. In addition, prior infection of a strain of influenza produces antibodies that will be responsible to protect against future infections compared to the same strain.
                However, these claims have come to consider as the tenets that characterize the disease in question is put in doubt when the observed seroprevalence of influenza A viruses in pigs is much higher than the number of reported clinical cases of swine flu. Finally, a key point of the swine flu is that the pig is traditionally described as a crucible with a potentially new virus recombination, demonstrating the emergence of pandemic viruses such as H1N1 in early 2009, which contained genes for both pigs and avian and human. However, this point has not been demonstrated under field conditions.
                During the second half of 2009 and the first half of 2010 there were two jobs at two farms sampled longitudinal closed-loop positive for influenza. Sampling was performed weekly in a whole lot of pigs on each farm to determine the dynamics of virus infection. In one of the two farms was detected circulating influenza subtype H1N2 in week 17 of life affecting 72% of the sampled animals. There was a very mild respiratory symptoms and subsequently seroconverted animals. On the other holding viral shedding was detected at weeks 3, 4, 7, 13, 15, 17 and 20 of life, with maximum and minimum prevalence of 26% to 3% respectively. We isolated two strains of subtype H1N1 (H1N1a and H1N1b) partially different level of neuraminidase in weeks 3, 4, 7 and 13, and only H1N1a at weeks 15, 17 and 20. In addition, seroconversion was detected animals between weeks 17 and 20 against the H3N2 subtype that was not provided in isolation. Not detected clearly consistent with the flu clinic at any time of the study. In the first operation, there was a classic outbreak of influenza, caused by the entry of a flu strain not previously present in the group of animals, with rapid transmission and clinical signs, although very mild, consistent with influenza. In the second operation, however, there are multiple peaks of infection that do not have the typical pattern of influenza transmission, affecting a small percentage of animals in different weeks of life also are not reflected in clinical symptoms. It should be noted that there are animals that are infected at two different times by the same strain, suggesting partial protection is not sterile can not prevent infection but if the clinic. This situation implies the presence of several influenza virus was endemic and subclinical exploitation, which would facilitate, if input from other different strains, new virus recombinations.
                In conclusion, the results observed in the second operation is not explained in any case, it would be expected in reference to what is known about the infection of influenza virus in pigs. From our point of view should be taken into account in relation to plans for surveillance of influenza due to the public health implications that this might entail.
                I'm interested in expert panflu damage estimates
                my current links: [url]http://bit.ly/hFI7H[/url] ILI-charts: [url]http://bit.ly/CcRgT[/url]

                Comment


                • #9
                  Re: Scientists to probe Mexican town's flu mystery

                  That's kind of confusing...

                  So the first farm had H1N2 and the outbreak was typical.

                  The second farm had H1N1b a number of times; then infected with H1N1a and H3N2 in the last 2-3 weeks. This outbreak was not typical due to multiple peaks of infection, small numbers of pigs infected and "also are not reflected in clinical symptoms." (no clinical symptoms?)

                  In the following, I dont understand the part I bolded: "but if the clinic"

                  It should be noted that there are animals that are infected at two different times by the same strain, suggesting partial protection is not sterile can not prevent infection but if the clinic. This situation implies the presence of several influenza virus was endemic and subclinical exploitation, which would facilitate, if input from other different strains, new virus recombinations.
                  The salvage of human life ought to be placed above barter and exchange ~ Louis Harris, 1918

                  Comment


                  • #10
                    Re: Scientists to probe Mexican town's flu mystery

                    lo que sugiere una protección parcial no esterilizante que no es capaz de impedir la infección pero si la clínica.
                    I'm interested in expert panflu damage estimates
                    my current links: [url]http://bit.ly/hFI7H[/url] ILI-charts: [url]http://bit.ly/CcRgT[/url]

                    Comment

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