Is H7N9 Spreading from Human to Human in China?

[JimO]

Re: Is H7N9 Spreading from Human to Human in China?

According to the CDC, no confirmed cases have been detected in over 100 contacts tested. Of course, no information is provided as to which contacts were tested, whether they were symptomatic, or whether they have been treated.

My guess is that China is going to avoid producing any information that would confirm H2H transmission for as long as they possibly can. It might have to show up in Hong Kong or Japan before we'll know.

Does anyone know if the contacts are being treated prophylactically with Oseltamivir or other antiviral? If they are/were, would this masque the capability of the virus to spread H2H?

 

[curiosity]

Re: Is H7N9 Spreading from Human to Human in China?

Known:

Human cases of H7N9 previously undetected in humans
Quite a few cases detected in short period of time, some posthumously, without epidemiological link
Cases are in a substantial geographical area
H7N9 detected in chickens, pigeons, and the environment in Shanghai
No "Known" contacts or healthcare works are sick
Mammalian adaptation (unknown degree) apparent on genetic analysis

Unknown:

Reservoir
The case exposure type
How the case was exposed
The case exposure time

Possible causes:

1. Inefficient human to human spread (High efficiency = alot more cases, i.e., 20-30% infection rate in families)

and/or

2. Chicken/wild bird exposure - one would expect the sudden rate of case growth and the geographical spread would mean that the virus infections have been ongoing undetected for a good clip of time and we have only been able to identify the virus recently (second, of course to the undetected illness due to low pathogenicity in fowl)

and/or

3. Environmental exposure - food borne illness.

a. Infection at a farm distributing fresh (untreated, uncooked)
produce with environmentally infectious virus - presumably from
bird droppings?

b. Infection at a slaughterhouse distributing meat infected products to
population at large over wide geographical area

c. Infection at an egg distributer

Option 3 might explain the reason why retired folks and cooks are ill?

Any other possibilities besides Human to Human spread?

 

[Giuseppe]

Re: Is H7N9 Spreading from Human to Human in China?

H7 was not traced by animal health in China so far.

Previously, almost all H5N1 human Chinese cases had not obvious contacts with poultry.

OIE has received two notifications from China (today) about several samples of chicken, pigeons and from environment positive for H7N9.

The virus is on poultry but it is not clear how widespread.

There are some behavioral issues that are deserving to be investigated in China related to poultry and birds management by people.

The PLoS paper I suggested (from a renowned Canadian expert) may be useful in detecting through a simple stochastic algorithm the likelihood of a h2h spread.

I suspect we need to collect things and doing some calculation (as other need, WHO firstly...)

 

[AlaskaDenise]

Re: Is H7N9 Spreading from Human to Human in China?

According to the CDC, no confirmed cases have been detected in over 100 contacts tested. Of course, no information is provided as to which contacts were tested, whether they were symptomatic, or whether they have been treated...........

In an NPR interview today, Laurie Garrett stated that contacts are SELF REPORTING flu symptoms after a telephone contact. She points out that contacts might be reluctant to report symptoms since they could be held in quarantine.

Link to interview is in this post: http://www.flutrackers.com/forum/showthread.php?t=203045

.

 

[curiosity]

Re: Is H7N9 Spreading from Human to Human in China?

http://www.iesingapore.gov.sg/wps/w..._food_in_China_2011_-_Article.pdf?MOD=AJPERES


An interesting analysis on food distribution in China- particularly because of the changes from "mom and pop" to large retailers like Wal Mart, KFC, McDonalds... in recent years with their economic growth.

 

[curiosity]

Re: Is H7N9 Spreading from Human to Human in China?

In an NPR interview today, Laurie Garrett stated that contacts are SELF REPORTING flu symptoms after a telephone contact. She points out that contacts might be reluctant to report symptoms since they could be held in quarantine.

Link to interview is in this post: http://www.flutrackers.com/forum/showthread.php?t=203045

.

So true. On the other hand, they might report just about anything because they want to receive treatment - particularly after having seen what the virus will do to the person they had contact with?

What about healthcare workers? Is there any indication yet that ANY of the people providing care to the sick have become ill? Are they in isolation because of the possibility? Are they able to go home? pH1N1 caused several mild/moderate illness in the HCW in as little as 7 days after the first contact with the initial cases in Mexico.

 

[JimO]

Re: Is H7N9 Spreading from Human to Human in China?

I think that it is safe to assume that there are unreported cases, particularly if they are mild.

Could this have been a H7N9 fatality?

http://www.flutrackers.com/forum/showthread.php?t=202268

These two cases (one fatal) are reported to have been H5N1. I believe it is possible that the Chinese knew these were H7N9, but didn't want to admit it.

http://www.flutrackers.com/forum/showthread.php?t=200294

Two more "confirmed H5N1 cases" with no poultry exposure and no immunological connection.

http://www.flutrackers.com/forum/showthread.php?t=200015

Also, there were incidences of poultry infections in late 2012 and early 2013 that were attributed to H5N1. Perhaps some of those were actually H7N9?

http://www.flutrackers.com/forum/showthread.php?t=185782
http://www.flutrackers.com/forum/showthread.php?t=200467
http://www.flutrackers.com/forum/showthread.php?t=200468
http://www.flutrackers.com/forum/showthread.php?t=200840

This reports claims 2,000 ducks died from E. coli and 30,000 were culled. I haven't heard of culling on such a scale due to E. coli.

http://www.flutrackers.com/forum/showthread.php?t=200407

And then, this report indicated the sudden death of ~100 in chickens back in January in Jiangsu Province and the cause was attributed to fireworks over 10 km away. This isn't far from where the pigs were disposed of in the river, I believe.

http://www.flutrackers.com/forum/showthread.php?t=197757

So, some additional facts are:

1) Reports suggest widespread avian influenza in Southern China over the past 6 months.

2) At least 5 human infections were reported (some and maybe all were fatal) earlier this year and attributed to H5N1.

3) H7N9 appears widespread in poultry, but was not identified until the human cases showed up.

4) There were calls for banning Chinese exports by many countries late last year due to avian flu fears.

5) China is not known for its transparency in these matters.

So, the possibility exists that H7N9 has been circulating for months undetected in poultry, and even swine. It jumped to humans in February and has either been spread H2H or there were multiple infections from bird to human or swine to human over a broad geographic area in a relatively short time-frame. Either way, this is cause for concern. Obviously, if it jumped to humans and acquired the ability for H2H transmission over a period of weeks or months, it's a dangerous virus. If it can jump from animals to humans effectively, it's also dangerous.

If the recent poultry outbreaks and human infections were truly H5N1 (not H7N9, E. coli, fireworks, starvation, or Attack of the Killer Tomatoes), then that raises the spector of widespread co-circulation of H5N1 and H7N9, which I assume is not a good thing since both can infect humans.

Any way you look at it, IMHO, this is a dangerous virus.

 

[curiosity]

Re: Is H7N9 Spreading from Human to Human in China?

Emerging microbiological food safety issues related to meatM.P. Doyle *, M.C. Erickson

"Humans acquire avian influenza viruses primarily through direct
contact of the mucous membranes with infectious secretions
and excreta from infected birds or contaminated poultry products (Perdue & Swayne, 2005).
Examples of these pathways include:

Inhalation of dust generated from feces or respiratory
secretions of infected poultry in the poultry farm
environment.

Inhalation of fine water droplets produced during
slaughter and processing, especially at wet markets.

Hand-to-mucous membrane (oral or nasal mucous
membranes or the conjunctiva) transfer of feces or respiratory
secretions of infected poultry from shoes, clothing,
or environmental sources.

Mucous membrane or inhalational exposure via mouth
suction of clogged nasal passages of fighting cocks.

Mucous membrane exposure through consumption of
raw undercooked blood, organs, or meat."

Imagine for a moment that lettuce from a farm is contaminated - The cook prepares the lettuce then touches their eyes, the person eats the lettuce subjecting oral mucous membranes to the virion.

This kind of outbreak happens all the time with Salmonella, E-Coli, etc... sudden and sometimes large number of geographically separated cases and no epidemiological link - except the food source. There are even family clusters because they eat the same food. There may even be an association between little to no pediatric cases - you know how they are about vegetables (The food borne illness is an optomistic scenario. Food exposure is a heck of alot easier to deal with than H2H spread.)

 

[Roehl_JC]

Re: Is H7N9 Spreading from Human to Human in China?

My understanding is that this H7N9 is treatable with both Oseltamvir (Tamiflu) and Relenza. If so, there's still ways to treat and even ways to suppress early symptoms.

 

[JimO]

Re: Is H7N9 Spreading from Human to Human in China?

That's a good point. We will soon find out and meanwhile hold our collective breath. If contaminated food is the source, then infections should disappear over the next few weeks. If it is solely from poultry to human infections, then all the control measures being taken should effectively stop the spread.

Emerging microbiological food safety issues related to meatM.P. Doyle *, M.C. Erickson

"Humans acquire avian influenza viruses primarily through direct
contact of the mucous membranes with infectious secretions
and excreta from infected birds or contaminated poultry products (Perdue & Swayne, 2005).
Examples of these pathways include:

Inhalation of dust generated from feces or respiratory
secretions of infected poultry in the poultry farm
environment.

Inhalation of fine water droplets produced during
slaughter and processing, especially at wet markets.

Hand-to-mucous membrane (oral or nasal mucous
membranes or the conjunctiva) transfer of feces or respiratory
secretions of infected poultry from shoes, clothing,
or environmental sources.

Mucous membrane or inhalational exposure via mouth
suction of clogged nasal passages of fighting cocks.

Mucous membrane exposure through consumption of
raw undercooked blood, organs, or meat."

Imagine for a moment that lettuce from a farm is contaminated - The cook prepares the lettuce then touches their eyes, the person eats the lettuce subjecting oral mucous membranes to the virion.

This kind of outbreak happens all the time with Salmonella, E-Coli, etc... sudden and sometimes large number of geographically separated cases and no epidemiological link - except the food source. There are even family clusters because they eat the same food. There may even be an association between little to no pediatric cases - you know how they are about vegetables (The food borne illness is an optomistic scenario. Food exposure is a heck of alot easier to deal with than H2H spread.)

 

[JimO]

Re: Is H7N9 Spreading from Human to Human in China?

I have heard the same thing and this could bridge the gap until an effective vaccine is developed and produced.

My understanding is that this H7N9 is treatable with both Oseltamvir (Tamiflu) and Relenza. If so, there's still ways to treat and even ways to suppress early symptoms.

 

[jflorida]

Re: Is H7N9 Spreading from Human to Human in China?

Im sure some of you already mentioned this but I am still wondering if it was somehow related:

Rivers of blood: the dead pigs rotting in China's water supply - Friday 29 March 2013 [ http://www.guardian.co.uk/world/2013/mar/29/dead-pigs-china-water-supply ]

Shanghai's drinking water is under threat after 16,000 diseased pig carcasses are found in tributaries of the Huangpu river

This area of Zhejiang province, 60 miles from Shanghai, has become the subject of public and media scrutiny after more than 16,000 dead pigs were found in tributaries of the city's river, the Huangpu, a source of tapwater. As clean-up efforts wind down, mystery surrounds the cause of the pigs' demise and their appearance in the river.

The first pigs were spotted on 7 March and were soon traced to Jiaxing through tags in their ears. Early tests show they carry porcine circovirus, a common disease among hogs not known to be infectious to humans. Shanghai's municipal water department maintains that the water meets the national standard, but hasn't said much more.

The Daily Mail (I know) actually had a article discussing this a few days ago, they also link to a more in depth article at foreignpolicy.com :

Is new bird flu outbreak linked to 20,000 dead pigs? Three die in China as scientists isolate new strain of killer virus [ http://www.dailymail.co.uk/news/art...d-pigs-swans-ducks-linked-new-fatalities.html ]

Tests on some of the dead pigs later revealed evidence of PCV-2 - a virus that is harmless to human beings, as well as birds.
However PCV-2 it is only supposed to be fatal to fetuses and newborn piglets and the pigs tested were all adult.

In an intriguing piece, Pulitzer Prize-winning science writer Laurie Garrett has now suggested that the virus that killed the pigs could be linked to the new strain of bird flu.

 

[jflorida]

Re: Is H7N9 Spreading from Human to Human in China?

Here are some stories about the pigs, dead ducks and swans in the general region as well for review. In line with the topic of the thread there seems to be ample possibilities in existing narrative for a large scale exposure to a new virus for humans, livestock and animals in the wild. It is possible the environment was saturated with this new virus. In other words, to me, this believably could have well been picked up on early; before human to human spread occurred even with the seemingly large number of cases.

No threat from Sichuan dead duck dumping: official - 2013-03-25 [ http://news.xinhuanet.com/english/china/2013-03/25/c_132261020.htm ]

More than 1,000 ducks had been fished out of the Pengshan section of the Nanhe River as of Monday morning, said Liang Weidong, an official with the county's publicity office.


China pulls 1,000 dead ducks from Sichuan river- 25 March 2013 [ http://www.bbc.co.uk/news/world-asia-china-21921145 ]

Officials discovered over 50 woven bags which contained the carcasses of around 1,000 ducks in the river.

They were unable to determine the cause of death as some of the ducks were already decomposed, Mr Liang said, adding that the bodies had been disinfected and buried.


Five floating dead black swans join China’s animal apocalypse - March 27, 2013 [ http://www.danwei.com/five-floating-dead-black-swans-join-chinas-animal-apocalypse/ ]

At the north-eastern corner of Anhui University’s old campus in Hefei, capital of Anhui province, there’s a scenic pond that’s inhabited by a bevy of black swans. The swans have been there for more than a decade already, and were – as the front page of local newspaper Star News (市场新报) laments today – an object of fondness for locals.


China Reportedly Finds More Dead Pigs Floating In River Hundreds Of Miles Away From First Discovery [ http://www.businessinsider.com/more-dead-pigs-found-in-china-2013-3 ]

more reports in Chinese media about dead ducks and dead pigs. Perhaps the ducks are unrelated, but the 50 dead pigs in Hunan province are certainly an alarming coincidence.



Chinese Crackdown On Pork Black Market Led To Dumping Of Thousands Of Dead Pigs - Mar. 26, 2013[ http://www.businessinsider.com/chinas-dead-pig-trade-2013-3 ]

While pig breeders in China are legally barred from sending pigs that die from disease or natural causes to butchers, estimates suggest that dead pigs being sold on the black market might make up to 10 percent of China's pork supply, the South China Morning Post reports.

In an interview with China's CCTV this week, Pan Huimin, a resident of the region where the pigs were first found, told the crew there was a “100 per cent” correlation between the pigs in the river and his own arrest for dealing in dead pigs.

 

[Laidback Al]

Re: Is H7N9 Spreading from Human to Human in China?

jflorida - Although it is not confirmed, it is assumed that there is a natural (animal) reservoir for H7N9. However, we have to rely on Chinese specialists to report both animal and human infections of H7N9. Those reports are still coming in.
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[jflorida]

Re: Is H7N9 Spreading from Human to Human in China?

Just saying the possibility for the argument or a similar one exists from what little is known to have occurred. Doesn't rule anything out. And likely it is well beyond its initial natural reservoir in such an environment and now is endemic to the area and has many reservoirs in the wild and in domesticated animals there. Especially as there doesn't seem to be a overwhelming contact story that is common between cases.

Really I think the conditions and defacto mechanisms of the area are far more alarming than any one organism's acquired traits. Its a laboratory; disastrous soup of accelerated opportunity and potential for pathogens that really cannot occur in nature and natural populations. God only knows what has happened there and what its full effects will be on people and organisms in the natural environment.

 

[curiosity]

Re: Is H7N9 Spreading from Human to Human in China?

Have there been any "new onset" cases since April 1? All reported cases so far with known symptom onset date, appear to be from March and February.

 

[jflorida]

Re: Is H7N9 Spreading from Human to Human in China?

That sounds correct from what I have read.

China closes poultry sale in third city after bird flu outbreak [ http://www.cnn.com/2013/04/06/world/asia/china-bird-flu/index.html?hpt=hp_t2 ]

As of Saturday evening, China had confirmed 18 human infections of the H7N9 avian flu virus, Xinhua reported. The World Health Organization confirmed 16.

Two other men, ages 66 and 74, developed flu symptoms late last month and were diagnosed with pneumonia over the past two days, Chinese officials said. A total of 11 people who had close contacts with the two have not shown flu symptoms, officials said.

 

[jflorida]

Re: Is H7N9 Spreading from Human to Human in China?

A bit more back-story on the pigs and stuff. As the dead animals dumped probably were being shipped to illegal slaughterhouses that had been closed, they also likely had come from diverse backgrounds and had varied causes of death. So I dont think testing was sufficient to rule out anything. I think other animals could be involved in this kind of illegal market activity as well. As unlikely as a mass water borne infection may seem, I think the potential is there , especially to other animals and I dont feel it has been ruled out with such monumental contamination issues.

Dead pigs threaten waterway - 2013-3-11 [ http://www.globaltimes.cn/content/767158.shtml#.UWBov6Ksh8E ]

According to the ear tags of the dead pigs, they were from farms in Jiaxing and Pinghu in Zhejiang Province, xinmin.com, a Shanghai-based news portal, reported, citing the Shanghai Songjiang District Agricultural Commission.


Pig removal done - 2013-3-30 [ http://www.shanghaidaily.com/nsp/Metro/2013/03/30/Pig+removal+done/ ]

The city didn't release the number of carcasses found yesterday, if any. On Thursday, the total was 11,257. Xu said Shanghai plans to set up an emergency system to help ensure water safety.


Huangpu River pigs didn't die of H7N9 - Apr 2, 2013 [ http://www.digitaljournal.com/article/347040 ]

Out of 34 samples of pig carcasses, no bird flu virus was found. So far, only one pig tested positive for porcine circovirus, which can be deadly for pigs but is harmless for humans.



Third death from H7N9 bird flu - 3 April 2013 [ http://www.guardian.co.uk/world/2013/apr/04/third-death-h7n9-bird-flu ]

Chinese authorities have said there is no evidence the strain spreads easily between humans but experts say it seems to move through poultry without making them sick, making it hard to track, and possesses genetic markers that indicate it is infectious to people.

Flu viruses evolve constantly and scientists say such changes have made H7N9 more capable of infecting pigs.

Pigs are a particular concern because bird and human flu viruses can mingle there, potentially producing a bird virus with heightened ability to spread between humans, said Dr William Schaffner, a flu expert at the Vanderbilt University School of Medicine. This happened in 2009 with swine flu.


Human Cases Of Bird Flu In China Draw Scrutiny - April 05, 2013 [ http://www.npr.org/blogs/health/2013/04/05/176354263/human-cases-of-bird-flu-in-china-draw-scrutiny ]

It's a bird virus, not a mélange of bird and pig viruses the way the pandemic H1N1 flu virus of 2009 was. But this H7N9 doesn't kill birds or even make them very sick. So it's hard to track through infected flocks.

The new H7N9 has been evolving under the radar for quite some time, picking up mutations that allow it to infect mammalian cells, including ours.

In the absence of person-to-person spread, the best bet to explain the sudden, widely scattered cases of H7N9 in southeastern China is that people are catching it from poultry. Frieden notes it has been found so far in pigeons (a market item in China) and chickens.

 

[curiosity]

Re: Is H7N9 Spreading from Human to Human in China?

If people are catching it from poultry, then, why so many sick - suddenly and simultaneously without a link to a SINGLE geographical location?

One would assume that IF all poultry are a reservoir, the mutation that made the virus jump to humans would have an origination point.

From the origination point where a virus is capable of creating illness in a population equally (if environment - i.e., poultry markets and human interaction are same) the illness would then become apparent in the population from the geographical origination as it spread through the susceptible fowl. The genetic "mutation" would not have happened simultaneously across the larger region.

I would hazard a guess by saying the rate of infection in the human population, if this were directly related to poultry, would mirror the rate of spread in fowl.

If tests prove fowl are carrying the current virus that is homologous with the human virus across a large geographical area, IMO it is likely the initial cases - many of the initial cases - were not detected and will not be detected. Likely falling into "seasonal influenza" death - no sub-typing done or testing not capable?

Piggies dying suddenly - perhaps they are also a victim of the mutation? The dying pigs in water causing the disease? One would think there would be so many more cases and there would be an epi link to a mutual water source.

IMO, H2H spread, may be extremely inefficient at this point, but occurring to some level. Post 1997 H5N1 serological testing proved there are many many more "cases" without symptoms. However, considering the wide spread and sudden impact this virus has created - knowing that the possible reservoir does not indicate illness (unlike H5N1), and knowing the birds in general can not be banned from China - wild birds included - we are one step closer, if not many steps closer to a truly novel flu pandemic.

On a positive note, even though it seems like little "official" information is coming out of China, I am confident the communications and alarm will still manage to get through - particularly if chaos sets in. It is comforting that the "weibos" are not showing images of crowded Emergency Rooms and hospitals ATM (at least not that I am aware of - please share with the FT community if they are).

 

[Nika]

Re: Is H7N9 Spreading from Human to Human in China?

One can not draw any conclusions about origin, timelines, etc because all info is confounded by the secretive nature of China and the very different nature of medicine in China. The ONLY reason we learned of the putative index case and his sons is because a hospital admin splashed a doc onto Weibo.

Its entirely possible that H7N9 has been killing people for much longer than the weeks between the "index" case and his splash onto social media.