Swine Flu in Indonesia : Unfolding the Facts — (Part 4)
Posted on October 2nd, 2009 in Global Focus Contagious_Disease, Pandemic
Warning from the past
At April 14th, 2005, news reported that bird flu identified in Indonesian pigs. Indonesian scientists have found the H5N1 bird flu virus in a pig. The strain has infected poultry across east Asia, and killed at least 51 people so far.
Scientists fear pigs could act as a “mixing vessel” in which a human pandemic strain could evolve, because the animals can harbour both human and avian flu viruses.
But while suspected, such hybridisation has never been proven. Furthermore, New Scientist has learned of preliminary results from scientists in the US that suggest pigs might not be able to transmit H5N1 flu to one another.
Java was the worst-affected part of Indonesia during 2004’s H5N1 bird flu outbreak. But by slaughtering and vaccinating poultry, Indonesia stopped the outbreak in October – with no reported human cases. But in April 2005, bird flu struck poultry throughout Java once again, mainly in village-based “backyard” flocks.
Indonesia offers free vaccination for such flocks. But vaccinated birds can still harbour and spread the virus unless they are strictly monitored for infection. Amin Soebandrio, a microbiologist and Indonesia’s assistant deputy minister for health sciences, told New Scientist that while larger farms do such monitoring, smallholders cannot.
C A Nidom, of Airlangga University in Surabaya, in East Java, has found the H5N1 virus in throat swabs and blood samples from a pig in Surabaya. It is the same “highly pathogenic” variant that causes severe disease in chickens. And, says Soebandrio, the isolated virus’s gene for a crucial surface protein, haemagglutinin, was more than 98% identical to samples taken from infected Indonesian chickens and quail.
Richard Webby of St Jude’s Children’s Research Hospital in Memphis, US, said that It was almost certainly true that viruses of different species can mix in pigs – pigs have numerous “hybrid” viruses. But the pig as a mixing vessel for human flu pandemics is just a hypothesis.
The pandemics of 1957 and 1968, which killed millions, did seem to result from the mixing of bird flu strains with mammalian flu, although where this occurred is not known. However, the even greater 1918 pandemic did not.
Robert Webster of St. Jude’s told a meeting on biosecurity in Lyon, France in March that his lab has found that H5N1 grows well in pigs, making hybridisation theoretically possible. But it might not get far – infected pigs do not pass H5N1 to each other. This means relatively few pigs will catch it.
Well, it seemed we all have overlooked this research’s result. H5 could infect only birds and poultries, while H1 could infect human and pigs. At the same time, pigs could be infected by H5 from birds and poultries. If this hybrid referred to deadly-H1N1-virus, it could have already occured.
Searching for the pandemic’s birth
It was hard to avoid swine flu pandemic. But, scientist won’t give up, never. There’re many ways to ‘beat’ this deadly disease. One of those ways was to search when this virus exactly emerged. We did not talk about the common swine flu, but more spesificly : the strain.
Scientists said the gene-swapping that gave rise to the newly discovered swine flu virus happened 10 or 20 years ago, and the triple virus spread among pigs for years. But until recently, the virus wasn’t able to spread among people. It acquired that ability only last year, when the older triple virus combined again with two other pig viruses that circulated in North American and Eurasian swine.
By analyzing the mutations in swine flu samples, scientists have assembled the most complete model to date of the pandemic’s birth.
Traditional modeling — the pins-on-a-map approach — relies on formal reports of a disease. Although these convey the big picture, they don’t always give a clear picture of how the disease spread.
But because flu viruses constantly pick up genetic mutations as they multiply, scientists can deduce a family tree by comparing the shared ancestry of their genomes.
“This helps reveal hidden information about the spatial spread of the virus,” said Marc Suchard, a University of California at Los Angeles biomathematician and co-author of the analysis, which was published last week in Public Library of Science Currents.
Other co-authors were Rega Institute molecular epidemiologist Philippe Lemey and Andrew Rambaut, the University of Edinburgh virologist whose genetic analyses provided the earliest insights into swine flu’s evolution into a human-infectious form.
The researchers ran 242 viral genomes, collected around the world between late March and mid-July, through algorithms that determined their most likely evolutionary path. From hundreds of trillions of possible configurations, the program arrived at the models above and below.
The model “helps us learn about the process by which the epidemic evolves,” said Suchard. “We can learn about the underlying epidemic process, and apply it to the future.”
There’re interesting videos who have been posted in www.wired.com. The video described how swine flu spread from a country to others. If you’ve seen these videos below, you might have a think, how did those pigs go from one to another country. Okay, pigs wouldn’t go anywhere (unless someone brought them with). It’s H1N1-infected-human in the flight zones!
Note: The video below is newer, but doesn’t clearly show swine flu spread outside North America. The video above is older and contains fewer data points, but gives a more complete sense of the virus’ global jumps.
Citation: “Reconstructing the initial global spread of a human influenza pandemic: A Bayesian spatial-temporal model for the global spread of H1N1pdm.” By Andrew Rambaut, Philippe Lemey and Marc Suchard. PLoS Currents, September 2, 2009.
Video: Philippe Lemey
Figure : Emergence of Influenza A (H1N1) Viruses from Birds and Swine into Humans.
Everybody should know about this. The H1N1 diagram above shows the emergence process of influenza A (H1N1) viruses during the past 91 years. It also decribe the important events, too, so we should be able to predict about this disease early and we are supposed not to be so surprised. We might have ‘created’ them accidentally. Avian, swine, and human populations are represented in the top, middle, and bottom of the diagram, respectively. Epidemic or zoonotic viruses are shown as wide horizontal arrows (white for avian viruses, light blue or pink for swine viruses, and dark blue for human viruses). Cross-species transmissions are shown as vertical dashed lines, with thick lines for transfers that gave rise to sustained transmission in the new host and thin lines for those that were transient and resulted in a self-limited number of cases. Principal dates are shown along the bottom of the diagram. The disappearance of H1N1 in 1957 most likely represents competition by the emerging pandemic H2N2 strain in the face of population immunity to H1N1. The reemergence in 1977 is unexplained and probably represents reintroduction to humans from a laboratory source. (Source : http://content.nejm.org/)
If this is true, then it is worse than I thought. Each vaccine would be failed. Each antibody would be failed to recognize. And if all of these things are really true, then 10-20 years from now, swine flu probably will become the most deadly virus on Earth.
Related posts:
- Swine Flu in Indonesia : Unfolding the Facts — (Part 2)
- Swine Flu in Indonesia : Unfolding the Facts — (Part 1)
- Swine Flu in Indonesia : Unfolding the Facts — (Part 3)
- Swine Flu in Indonesia : Unfolding the Facts — (Part 6)
- Swine Flu in Indonesia : Unfolding the Facts — (Part 5)
Assalamualaikum. Hello, I am Fauzan. Thank you for visiting my blog. To find out more about this site, please visit
*Widget By mfaisal
Leave a Comment