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H7N9 evolving but has not fully mutated: expert
2013/04/16 17:57:14
Michael M.C. Lai (CNA file photo)
Taipei, April 16 (CNA) The H7N9 avian influenza virus will not necessarily become transmissible among humans, but it does have a mutated gene that makes such a possibility greater, an expert said Tuesday.
The H7N9 virus, currently transmitted from poultry to humans, has spread widely in China, and health authorities in other countries are worried that the lethal bird flu strain could become transmissible among humans and pose a major challenge to epidemic controls.
Michael M.C. Lai, a distinguished research fellow at Academia Sinica specializing in corona-virus molecular biology, was reported as saying Monday that the H7N9 virus is evolving and would mutate into a form allowing human-to-human transmission sooner or later.
Lai clarified Tuesday, however, that he did not say the H7N9 virus will definitely become transmissible among humans, but that it has a mutated gene and may be more likely to cause a human pandemic in a short time if it infects more people.
Lai said he could not determine how the H7N9 virus will evolve, just as many people were unable to judge avian influenza A (H5N1).
Some predicted the H5N1 virus would mutate and spread among humans, only to find that "many years have gone by and what everybody worried about has yet to happen," Lai said.
The H7H9 virus does pose more challenges than the H5N1 flu, Lai said. H5N1-infected fowl die easily from the virus while H7N9-infected fowl live normally and show no symptoms, which is why H7N9 is not easily detected and China is having a hard time finding its source.
The H7N9 bird flu in China has spread to the north, seemingly following the route migratory birds take to their summer breeding grounds, Lai said, yet no migratory bird has died of a flu infection so far.
As a result, no conclusions can be drawn on whether migratory birds are H7N9 virus carriers, but if they are, Taiwan will become an H7N9-affected area as migratory birds begin flying south during the fall and winter, Lai said.
Taiwan has yet to get a close look at the H7N9 virus because it has yet to obtain samples of the flu strain, but Lai said that based on its gene sequence, the anti-flu medicine Tamiflu should be effective in combating it.
Former Health Minister Yeh Ching-chuan, meanwhile, urged the public not to panic over the H7N9 flu outbreak in China because test reagents for the bird flu virus are available in Taiwan.
Taiwan currently can detect and treat the virus and even has the ability to develop a vaccine, so local residents should not be worried about an outbreak, Yeh said.
Yeh also said the virus does not appear likely to mutate into a form that is transmissible among humans, but even if such a mutation were to occur, it would take a long time to happen, though Yeh did not specify how long.
The World Health Organization has made it clear that the risk of being infected with the H7N9 virus when traveling to China is very low, Yeh said, and there was therefore no reason to impose travel restictrictions on local citizens at present.
http://focustaiwan.tw/news/aall/201304160024.aspx
2013/04/16 17:57:14
Michael M.C. Lai (CNA file photo)
Taipei, April 16 (CNA) The H7N9 avian influenza virus will not necessarily become transmissible among humans, but it does have a mutated gene that makes such a possibility greater, an expert said Tuesday.
The H7N9 virus, currently transmitted from poultry to humans, has spread widely in China, and health authorities in other countries are worried that the lethal bird flu strain could become transmissible among humans and pose a major challenge to epidemic controls.
Michael M.C. Lai, a distinguished research fellow at Academia Sinica specializing in corona-virus molecular biology, was reported as saying Monday that the H7N9 virus is evolving and would mutate into a form allowing human-to-human transmission sooner or later.
Lai clarified Tuesday, however, that he did not say the H7N9 virus will definitely become transmissible among humans, but that it has a mutated gene and may be more likely to cause a human pandemic in a short time if it infects more people.
Lai said he could not determine how the H7N9 virus will evolve, just as many people were unable to judge avian influenza A (H5N1).
Some predicted the H5N1 virus would mutate and spread among humans, only to find that "many years have gone by and what everybody worried about has yet to happen," Lai said.
The H7H9 virus does pose more challenges than the H5N1 flu, Lai said. H5N1-infected fowl die easily from the virus while H7N9-infected fowl live normally and show no symptoms, which is why H7N9 is not easily detected and China is having a hard time finding its source.
The H7N9 bird flu in China has spread to the north, seemingly following the route migratory birds take to their summer breeding grounds, Lai said, yet no migratory bird has died of a flu infection so far.
As a result, no conclusions can be drawn on whether migratory birds are H7N9 virus carriers, but if they are, Taiwan will become an H7N9-affected area as migratory birds begin flying south during the fall and winter, Lai said.
Taiwan has yet to get a close look at the H7N9 virus because it has yet to obtain samples of the flu strain, but Lai said that based on its gene sequence, the anti-flu medicine Tamiflu should be effective in combating it.
Former Health Minister Yeh Ching-chuan, meanwhile, urged the public not to panic over the H7N9 flu outbreak in China because test reagents for the bird flu virus are available in Taiwan.
Taiwan currently can detect and treat the virus and even has the ability to develop a vaccine, so local residents should not be worried about an outbreak, Yeh said.
Yeh also said the virus does not appear likely to mutate into a form that is transmissible among humans, but even if such a mutation were to occur, it would take a long time to happen, though Yeh did not specify how long.
The World Health Organization has made it clear that the risk of being infected with the H7N9 virus when traveling to China is very low, Yeh said, and there was therefore no reason to impose travel restictrictions on local citizens at present.
http://focustaiwan.tw/news/aall/201304160024.aspx