-
FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
-
We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.
Is H7N9 Spreading from Human to Human in China?
- Thread starter Laidback Al
- Start date
Re: Is H7N9 Spreading from Human to Human in China?
Alaska Denise: as a personal opinion only but based on observation of the published data for some years [primarily in animal populations], it seems to me that unless vaccination has sufficient coverage to generate herd immunity in its target population, all partial vaccination does is increase natural selection pressures and accelerate evolution of the virus to newer formats which may or may not be worse than the original pathogen, as well as driving pathogen diversity and producing multiple variations of a pathogen co-circulating on a global scale where before there may have only been one predominant strain.
Observe what has occurred with H5N1 on a global scale where widespread vaccination has occurred; China/ Indonesia has seen the evolution of new clades of virus, almost as fast as vaccines are adjusted to counter its genetic evolution. Now that could be down to viral evolution in wild birds, or it just could be being driven by vaccination itself, where 100% coverage is not achieved in the target animal populations. What occurs in animal populations is likely to be mirrored in human ones IMHO.
I think detailed and proper scientific study is warranted to answer this question, because it is an important one for us to know the answer to. If it should be proven to be a problem, the way forward would be development of 'universal vaccines' for each major pathogen we want to vaccinate against, so that the virus could be effectively eradicated - but that would take a lot of money and research. I doubt there is the financial incentive for companies to follow this approach, unless or until there is a clear need for it - which is all the more reason for the research to be prioritised, lest mankind is setting itself up for all manner of problems in our immediate future.
Alaska Denise: as a personal opinion only but based on observation of the published data for some years [primarily in animal populations], it seems to me that unless vaccination has sufficient coverage to generate herd immunity in its target population, all partial vaccination does is increase natural selection pressures and accelerate evolution of the virus to newer formats which may or may not be worse than the original pathogen, as well as driving pathogen diversity and producing multiple variations of a pathogen co-circulating on a global scale where before there may have only been one predominant strain.
Observe what has occurred with H5N1 on a global scale where widespread vaccination has occurred; China/ Indonesia has seen the evolution of new clades of virus, almost as fast as vaccines are adjusted to counter its genetic evolution. Now that could be down to viral evolution in wild birds, or it just could be being driven by vaccination itself, where 100% coverage is not achieved in the target animal populations. What occurs in animal populations is likely to be mirrored in human ones IMHO.
I think detailed and proper scientific study is warranted to answer this question, because it is an important one for us to know the answer to. If it should be proven to be a problem, the way forward would be development of 'universal vaccines' for each major pathogen we want to vaccinate against, so that the virus could be effectively eradicated - but that would take a lot of money and research. I doubt there is the financial incentive for companies to follow this approach, unless or until there is a clear need for it - which is all the more reason for the research to be prioritised, lest mankind is setting itself up for all manner of problems in our immediate future.
sharon sanders
Editor-in-Chief & President
Re: Is H7N9 Spreading from Human to Human in China?
Does it strike anyone else as odd that everyday, at about the same time, 2 new H7N9 cases are announced?
It looks like the media is being "handled".
Does it strike anyone else as odd that everyday, at about the same time, 2 new H7N9 cases are announced?
It looks like the media is being "handled".
sharon sanders
Editor-in-Chief & President
Re: Is H7N9 Spreading from Human to Human in China?
The latest onset dates are April 1 and those are cases #22 & #23.
The latest onset dates are April 1 and those are cases #22 & #23.
Shannon Bennett
Well-known member
Re: Is H7N9 Spreading from Human to Human in China?
Yes, I believe there is one official person who is allowed to send reports to the media. Evidently that person's reports are due out at the same time everyday. This is China after all.
Yes, I believe there is one official person who is allowed to send reports to the media. Evidently that person's reports are due out at the same time everyday. This is China after all.
Re: Is H7N9 Spreading from Human to Human in China?
China: Academy of Sciences calls H7N9 a "hybrid" from Korean wild birds and Chinese ducks
The information in the above post makes sense and might have a clue why the disease is spread out over a larger geographic area.
The disease is a reassortment - perhaps just recently occuring in or around Shanghai/Yangtse River Delta area - AND perhaps it is also novel to avian species.
The rate of spread in humans would follow the movement of the disease, the concentration of the disease (which is likely growing larger) and the movement of the avian hosts through the environment. A relatively mild avian disease with a rapid spread would move much more quickly than a pathogenic avian disease that kills off over half the population carrying it to others (i.e. H5N1).
The cases over a large geographic area might be caused by a rapid spread through the avian population compounded by the ongoing migration through waterways.
I plotted the cases where onset and location were known. The cases do follow a spreading pattern up the Yangtse River and larger tributaries.
There are more cases occuring in Shanghai - as the concentration of disease in fowl increases perhaps?
At this early in the process the disease may only be detected in few domestic poultry because it is just beginning to affect them - and maybe the wild birds are indeed the reservoir?
The unfortunate part of this scenario is that this virus's genetic code is adapted enough to cause disease in humans without obvious or intense exposure routes. The worst part of that is, not knowing how many more adaptations in the gene sequence it will take before it becomes H2H - my uneducated guess is that the more humans infected, the more opportunity there is and the faster that will happen.
China: Academy of Sciences calls H7N9 a "hybrid" from Korean wild birds and Chinese ducks
The information in the above post makes sense and might have a clue why the disease is spread out over a larger geographic area.
The disease is a reassortment - perhaps just recently occuring in or around Shanghai/Yangtse River Delta area - AND perhaps it is also novel to avian species.
The rate of spread in humans would follow the movement of the disease, the concentration of the disease (which is likely growing larger) and the movement of the avian hosts through the environment. A relatively mild avian disease with a rapid spread would move much more quickly than a pathogenic avian disease that kills off over half the population carrying it to others (i.e. H5N1).
The cases over a large geographic area might be caused by a rapid spread through the avian population compounded by the ongoing migration through waterways.
I plotted the cases where onset and location were known. The cases do follow a spreading pattern up the Yangtse River and larger tributaries.
There are more cases occuring in Shanghai - as the concentration of disease in fowl increases perhaps?
At this early in the process the disease may only be detected in few domestic poultry because it is just beginning to affect them - and maybe the wild birds are indeed the reservoir?
The unfortunate part of this scenario is that this virus's genetic code is adapted enough to cause disease in humans without obvious or intense exposure routes. The worst part of that is, not knowing how many more adaptations in the gene sequence it will take before it becomes H2H - my uneducated guess is that the more humans infected, the more opportunity there is and the faster that will happen.
Giuseppe
Emeritus
Re: Is H7N9 Spreading from Human to Human in China?
Some sort of interuman transmission is ongoing Beyond any reasonable doubt.
If this transmission is fully or partly sustained it will be more clear as time will pass.
This kind of scenario could be refuted only when details of cases will be provided, such as - for the elderly - if they were used to do some leisure activity at open air entering in contact with birds or their manure, droppings.
Since no details were provided, and there is a continuing lack of veterinary evidence for a widespread epizootics in this area, the only reasonable explaination for the sudden increase in human cases in an oingoing community transmission.
Some sort of interuman transmission is ongoing Beyond any reasonable doubt.
If this transmission is fully or partly sustained it will be more clear as time will pass.
This kind of scenario could be refuted only when details of cases will be provided, such as - for the elderly - if they were used to do some leisure activity at open air entering in contact with birds or their manure, droppings.
Since no details were provided, and there is a continuing lack of veterinary evidence for a widespread epizootics in this area, the only reasonable explaination for the sudden increase in human cases in an oingoing community transmission.
sharon sanders
Editor-in-Chief & President
Re: Is H7N9 Spreading from Human to Human in China?
Then we might want to be searching the Pearl river delta area which is about 500 miles south of Shanghai:
The river delta, also known as the Golden Delta of Guangdong,[1] is formed by three major rivers, the Xi Jiang (West River), Bei Jiang (North River), and Dong Jiang (East River). The flat lands of the delta are criss-crossed by a network of tributaries and distributaries of the Pearl River. The Pearl River Delta is actually two alluvial deltas, separated by the core branch of the Pearl River. The Bei Jiang and Xi Jiang converge to flow into the South China Sea and Pearl River in the west, while the Dong Jiang only flows into the Pearl River proper in the east.
"The Pearl River Delta (PRD, Chinese: 珠江三角洲; pinyin: Zhūjiāng sānjiǎozhōu), Zhujiang Delta or Zhusanjiao in Guangdong province, People's Republic of China is the low-lying area surrounding the Pearl River estuary where the Pearl River flows into the South China Sea. It is one of the most densely urbanised regions in the world and one of the main hubs of China's economic growth. This region is often considered an emerging megacity. The PRD is not a megalopolis but rather one rapidly forming megacity, and itself the southern end of a larger megalopolis running along the southern coast of China, which include large metropolises like Chaoshan, Zhangzhou-Xiamen, Quanzhou-Putian, and Fuzhou.
http://en.wikipedia.org/wiki/Pearl_River_Delta
Then we might want to be searching the Pearl river delta area which is about 500 miles south of Shanghai:
The river delta, also known as the Golden Delta of Guangdong,[1] is formed by three major rivers, the Xi Jiang (West River), Bei Jiang (North River), and Dong Jiang (East River). The flat lands of the delta are criss-crossed by a network of tributaries and distributaries of the Pearl River. The Pearl River Delta is actually two alluvial deltas, separated by the core branch of the Pearl River. The Bei Jiang and Xi Jiang converge to flow into the South China Sea and Pearl River in the west, while the Dong Jiang only flows into the Pearl River proper in the east.
"The Pearl River Delta (PRD, Chinese: 珠江三角洲; pinyin: Zhūjiāng sānjiǎozhōu), Zhujiang Delta or Zhusanjiao in Guangdong province, People's Republic of China is the low-lying area surrounding the Pearl River estuary where the Pearl River flows into the South China Sea. It is one of the most densely urbanised regions in the world and one of the main hubs of China's economic growth. This region is often considered an emerging megacity. The PRD is not a megalopolis but rather one rapidly forming megacity, and itself the southern end of a larger megalopolis running along the southern coast of China, which include large metropolises like Chaoshan, Zhangzhou-Xiamen, Quanzhou-Putian, and Fuzhou.
http://en.wikipedia.org/wiki/Pearl_River_Delta
AlaskaDenise
In Memoriam
Re: Is H7N9 Spreading from Human to Human in China?
What you're saying (& appeared subjectively to me over several years) is the point of the quoted paper (Paradox of vaccination). While the solutions proposed in the paper are theoretically sound, as long as wild birds (& mammals) have any interactions with domestic birds (& others, like swine, horses, etc.) the theoretical solutions won't have the desired level of outcomes. It would sure help if cultures that prefer their protein "fresh" could learn to purchase it through frozen/refrigerated food chains. I suppose the "best" solution is that we all become vegan!
I truly question whether or not we can ever achieve a "universal" influenza vaccine. We may think we can overcome the HA variables, but influenza always seems to find a way to persist! I have more confidence in what we CAN control - prevention - through environmental factors and maximizing our body's immune system.
.
What you're saying (& appeared subjectively to me over several years) is the point of the quoted paper (Paradox of vaccination). While the solutions proposed in the paper are theoretically sound, as long as wild birds (& mammals) have any interactions with domestic birds (& others, like swine, horses, etc.) the theoretical solutions won't have the desired level of outcomes. It would sure help if cultures that prefer their protein "fresh" could learn to purchase it through frozen/refrigerated food chains. I suppose the "best" solution is that we all become vegan!
I truly question whether or not we can ever achieve a "universal" influenza vaccine. We may think we can overcome the HA variables, but influenza always seems to find a way to persist! I have more confidence in what we CAN control - prevention - through environmental factors and maximizing our body's immune system.
.
AlaskaDenise
In Memoriam
Re: Is H7N9 Spreading from Human to Human in China?
Birds may well be forced into more interaction from China's disappearing waterways. See:
Where have all the rivers gone?
China's burgeoning demand for water is having a big impact on its waterways.
How do you ?lose? a river? The answer is ?quite easily?, apparently. China has lost more than 25,000 of them in the last 30 years.
In a survey, released by the country?s Ministries of Water Resources and Statistics, the number of recorded rivers with catchment areas of over 100 square kilometres had fallen to just under 23,000 compared with a figure of 50,000 in the 1990s.
These figures come at a time when the government is still trying to explain the discovery, earlier this month, of 16,000 pig carcasses, floating along the Huangpu River, which supplies much of Shanghai with its drinking water. In the last week 1,000 dead ducks were found dumped in the Nanhe River in Sichuan province......
.
Birds may well be forced into more interaction from China's disappearing waterways. See:
Where have all the rivers gone?
China's burgeoning demand for water is having a big impact on its waterways.
How do you ?lose? a river? The answer is ?quite easily?, apparently. China has lost more than 25,000 of them in the last 30 years.
In a survey, released by the country?s Ministries of Water Resources and Statistics, the number of recorded rivers with catchment areas of over 100 square kilometres had fallen to just under 23,000 compared with a figure of 50,000 in the 1990s.
These figures come at a time when the government is still trying to explain the discovery, earlier this month, of 16,000 pig carcasses, floating along the Huangpu River, which supplies much of Shanghai with its drinking water. In the last week 1,000 dead ducks were found dumped in the Nanhe River in Sichuan province......
.
jflorida
Well-known member
Re: Is H7N9 Spreading from Human to Human in China?
I think the comment :
"There is no evidence that person to person transmission can occur"
is untrue. There may not be totally conclusive evidence or perhaps it doesn't occur like other influenza viruses. Certainly beyond what the authorities there publicly say their behavior as well as a few suspicious cases acknowledges at least the possibility it can and does occur:
Government ready to cull birds at first sign of 'bird flu' infection [ http://www.scmp.com/news/hong-kong/...eady-cull-birds-first-sign-bird-flu-infection ]
Schools with cross-border pupils are responding to the risk by increasing their flu prevention measures. Some were conducting extra temperature checks while others have cancelled morning assembly to reduce the chance of the virus spreading among pupils.
The children of Pui Yau Kindergarten in Sheung Shui who come from the mainland underwent two additional temperature checks on top of the two regular ones they undergo along their journey to school.
"Children's body temperature fluctuates a lot in the morning and their fever may not be shown at first. We don't want to have anyone slipping through the net," said principal Poo Siu-fung.
The mainland children have their first temperature reading when their parents take them to board the school bus. The second one is while they are on the bus, the third when they cross the border, and the final one when they arrive at the school gate.
At Pui Yau, the school is being disinfected with bleach of a higher concentration than what is used during regular cleaning over the weekend.
I think the comment :
"There is no evidence that person to person transmission can occur"
is untrue. There may not be totally conclusive evidence or perhaps it doesn't occur like other influenza viruses. Certainly beyond what the authorities there publicly say their behavior as well as a few suspicious cases acknowledges at least the possibility it can and does occur:
Government ready to cull birds at first sign of 'bird flu' infection [ http://www.scmp.com/news/hong-kong/...eady-cull-birds-first-sign-bird-flu-infection ]
Schools with cross-border pupils are responding to the risk by increasing their flu prevention measures. Some were conducting extra temperature checks while others have cancelled morning assembly to reduce the chance of the virus spreading among pupils.
The children of Pui Yau Kindergarten in Sheung Shui who come from the mainland underwent two additional temperature checks on top of the two regular ones they undergo along their journey to school.
"Children's body temperature fluctuates a lot in the morning and their fever may not be shown at first. We don't want to have anyone slipping through the net," said principal Poo Siu-fung.
The mainland children have their first temperature reading when their parents take them to board the school bus. The second one is while they are on the bus, the third when they cross the border, and the final one when they arrive at the school gate.
At Pui Yau, the school is being disinfected with bleach of a higher concentration than what is used during regular cleaning over the weekend.
gsgs
Registered User
Re: Is H7N9 Spreading from Human to Human in China?
when looking at the sequences
it looks to me that H7N9 evolved entirely in poultry after
that one introduction from a wild bird ~1 year ago.
From there it occasionally spreads to other species
but usually not sustained.
Maybe the concept of backyard poultry is not a good idea.
Can we give these people some other animals to raise and slaughter ?
Or genetically create the chicken that doesn't get flu
----------edit-------------
also confirmed by Peiris:
http://www.scmp.com/news/hong-kong/article/1210222/dna-points-poultry-markets
evidence suggests wild birds do not play a role in transmission of the virus
when looking at the sequences
it looks to me that H7N9 evolved entirely in poultry after
that one introduction from a wild bird ~1 year ago.
From there it occasionally spreads to other species
but usually not sustained.
Maybe the concept of backyard poultry is not a good idea.
Can we give these people some other animals to raise and slaughter ?
Or genetically create the chicken that doesn't get flu
----------edit-------------
also confirmed by Peiris:
http://www.scmp.com/news/hong-kong/article/1210222/dna-points-poultry-markets
evidence suggests wild birds do not play a role in transmission of the virus
Re: Is H7N9 Spreading from Human to Human in China?
Maybe genetically create children that don't catch it either?
Maybe genetically create children that don't catch it either?
gsgs
Registered User
Re: Is H7N9 Spreading from Human to Human in China?
mice first, then chickens, then ..., then children
(if it works)
I read one report about such chickens some years ago,
but never heard it again. Apparently it didn't work so well
as announced or the chickens were too expensive
I can't find it now
mice first, then chickens, then ..., then children
(if it works)
I read one report about such chickens some years ago,
but never heard it again. Apparently it didn't work so well
as announced or the chickens were too expensive
I can't find it now
Emily
Editor, Senior Moderator
Re: Is H7N9 Spreading from Human to Human in China?
http://www.nytimes.com/2013/04/09/world/asia/china-avian-flu.html?_r=0
I suppose it's also possible that instead of H7N9, the infection in common could be a new zoonosis that interferes with the immune response of the respiratory system. It could be so novel in humans that it isn't even being tested for.
http://www.nytimes.com/2013/04/09/world/asia/china-avian-flu.html?_r=0
I suppose it's also possible that instead of H7N9, the infection in common could be a new zoonosis that interferes with the immune response of the respiratory system. It could be so novel in humans that it isn't even being tested for.
jflorida
Well-known member
Re: Is H7N9 Spreading from Human to Human in China?
Hopefully not a issue in the bird tests, or at least in this case but it was a interesting read :
Inability of Real-Time Reverse Transcriptase PCR Assay To Detect
Subtype H7 Avian Influenza Viruses Isolated from Wild Birds [ http://jcm.asm.org/content/46/5/1844.full.pdf ]
Hopefully not a issue in the bird tests, or at least in this case but it was a interesting read :
Inability of Real-Time Reverse Transcriptase PCR Assay To Detect
Subtype H7 Avian Influenza Viruses Isolated from Wild Birds [ http://jcm.asm.org/content/46/5/1844.full.pdf ]
AlaskaDenise
In Memoriam
Re: Is H7N9 Spreading from Human to Human in China?
Hopefully that has been corrected since the paper was written in 2008. That means the 163,451 tests in their database by 2006 may contain erroneous results! While they say the problem was eventually found to be a probe mismatch, perhaps it indicates how well infuenza can adapt for different species of one host type.
.
Hopefully that has been corrected since the paper was written in 2008. That means the 163,451 tests in their database by 2006 may contain erroneous results! While they say the problem was eventually found to be a probe mismatch, perhaps it indicates how well infuenza can adapt for different species of one host type.
.
jflorida
Well-known member
Re: Is H7N9 Spreading from Human to Human in China?
I hope it isnt a issue here for the wild bird tests if they are using the same procedure.
I looked up that H7N7 outbreak in the Netherlands back in 2003 if any of you remember that - a vet died - and here is that article if someone is interested:
Transmission of H7N7 avian influenza A virus to human beings
during a large outbreak in commercial poultry farms in the
Netherlands [ http://www.impact.arq.org/doc/kennisbank/1000010929-1.pdf ]
Virological analysis
The proportion of samples positive for A/H7 was highest in
the first 4 days from the onset of illness, and eye swabs were
more frequently positive than were throat swabs. Maximum
detection rates were 44% of eye swabs collected on the
second day of illness, and 12% for throat swabs taken on
the second day of illness (figure 2). 39 eye swabs shown to
be positive by RT-PCR were cultured. 31 (79%) of these
yielded infectious A/H7 virus.
Again not sure how much has changed/if it applies to the current situation but assuming "onset of illness" means infected the PCR detection rates seem a bit low.
I hope it isnt a issue here for the wild bird tests if they are using the same procedure.
I looked up that H7N7 outbreak in the Netherlands back in 2003 if any of you remember that - a vet died - and here is that article if someone is interested:
Transmission of H7N7 avian influenza A virus to human beings
during a large outbreak in commercial poultry farms in the
Netherlands [ http://www.impact.arq.org/doc/kennisbank/1000010929-1.pdf ]
Virological analysis
The proportion of samples positive for A/H7 was highest in
the first 4 days from the onset of illness, and eye swabs were
more frequently positive than were throat swabs. Maximum
detection rates were 44% of eye swabs collected on the
second day of illness, and 12% for throat swabs taken on
the second day of illness (figure 2). 39 eye swabs shown to
be positive by RT-PCR were cultured. 31 (79%) of these
yielded infectious A/H7 virus.
Again not sure how much has changed/if it applies to the current situation but assuming "onset of illness" means infected the PCR detection rates seem a bit low.