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Chinese son likely gave bird flu to father: report
Re: Chinese son likely gave bird flu to father: report
how can we be sure that we hear about all the H2H occurances in china/pakistan/korea/etc? would there be villages/provinces too afraid to contact authorities about their sick? would there be clusters in remote areas that we would never hear about?
sorry - i'm getting a little paranoid and worried..
Last edited by sharon sanders; April 8, 2008, 02:36 PM.
Reason: typo
how can we be sure that we hear about all the H2H occurances in china/pakistan/korea/etc? would there be villages/provinces too afraid to contact authorities about their sick? would there be clusters in remote areas that we would never hear about?
sorry - i'm getting a little paranoid and worried..
Paranoid! No.... The cases happened in December! With the highest inhabitants density rate of the world, southern China would have accounted an amount of fatalities if a more tansmissible virus was emerged in relation to the discovery of this familiar cluster.
Again, continuing overlooked socio-economical, demographic, and epidemiological evidences lead to improper facts evaluation.
If one decides to start panicking every time media fanfare happens, it is time to stop to read and move further.
Excuse me, but I currently experience a bit of disappoint for these booming news writers (I refer to major press agencies not reviews), too anxious and too little open in geographical, demographic and socio-economics determinants in the background of the facts they are talking.
wow...i can't tell if you're pissed off at me or someone else...
i'm just going to read posts for awhile...i can see that i'm clearly out of my league...
note: i love reading your posts; even if i don't understand hardly any of them...
Oh no! Please excuse me for the irruence and I hope you will accept this apology. You are welcomed as I was at FT, of course. I would like only to highlight the need to put every event in a correct perspective; often, media reports tend to speculate a bit about promising pieces of news. IoH
wow...i can't tell if you're pissed off at me or someone else...
i'm just going to read posts for awhile...i can see that i'm clearly out of my league...
note: i love reading your posts; even if i don't understand hardly any of them...
Janetney, I don't think IOH is directing his comments to you. He is speaking about the media reporting process. H2H transmission is regularly occurring in several countries. Only now is it making news in main stream media. IOH is pointing out that the China cases as well as the Pakistan cases of H2H happened several months ago; if it were easily transmissible we would be in the middle of a pandemic right now.
The concern is that reporters and media outlets are twisting the news to sensationalize it and place it in the immediate present. Old news, stale news does not sell.
An increase in main stream news articles about H2H transmission will have no causal affect on a pandemic. The pandemic will occur when all of viral pieces fall into place and it becomes easily transmissible.
Last edited by Laidback Al; April 9, 2008, 12:41 AM.
Reason: I'll leave this post, even though IOH has addressed your post.
Re: Chinese son likely gave bird flu to father: report
i am mortified that you think my feelings were hurt...by no means! i can only imagine your frustration at the MSM and the sensationalization of any news about birdflu...
i love this site...i feel comfort at this site...
i just re-read my post and it DID sound like i was upset...i'm so sorry!
you all are so amazing in your research and knowledge and ability to break down information...i am in awe...
Re: Chinese son likely gave bird flu to father: report
We like you too Janet. We have many different languages and cultures here which makes for some interesting conversations! Sometimes there are some small misunderstandings. For example, I never knew that there were so many different dialects of English around the world. lol
While we are all from different backgrounds, we speak with the same heart.
The heart of compassion, understanding, and acceptance.
Re: Chinese son likely gave bird flu to father: report
what a beautiful post...thank you...
as for the different dialects: i'm from the 'south' (Texas) - right on the gulf coast, and yes, i'm cajun...so, if you were to hear my voice, you would laugh VERY hard....so, i know about sounding different! it's fun, isn't it? ha!
and living in california makes it even more interesting! my own kids make fun of me!
but, thank you for being so welcoming...you don't know how much i appreciate it....
While Henan cannot be considered Southern China, it is on a direct line through Anhui to Jiangxi. Earlier ingestion of contaminated water or pork certainly would be consistent with a prolonged Salmonella infection.
We have:
Possible underlying disease (my bet is on choleothiasis), clearly linked to the aforementioned but otherwise rare, Salmonella empeyma thoracis, with lack of white blood cell count elevation, indicating immune suppression (that may or may not have been excerbated by HDCV series vaccine in the month before acute infection onset).
I think the index patient didn't die of H5N1 infection (although it was probably present as a secondary infection). He died of late and inappropriate treatment for a long-standing Salmonella infection that had already progressed to rampant pneumonia. Furthermore, in Taiwan cases of Salmonella enterica subtype choleraesuis was found to be drug resistant in more than 2/3rds of thoracic empeyma cases, exhibiting high case mortality as a result of inappropriate drug treatment.
Case 2 is similarly interesting, because of underlying liver disease, but is otherwise a more straightforward direct H5N1 infection.
The real reason for the publication hoopla is the use of anti-sera in Case 2.
Here is an NA travel log for a wild bird in China. There is an intimate relationship between wild birds and swine alathough its not limited to China (although this travel log includes wild birds in China). Wild bird in black bold (H5N1 from 2005/2006), swine in red, human in red bold
gb|CY030737.1| Influenza A virus (A/swine/Tennessee/9/1978(H1... 36.2 0.005 gb|EU502888.1| Influenza A virus (A/swine/Shanghai/1/2005(H1N... 36.2 0.005 gb|EU429763.1| Influenza A virus (A/duck/Eastern China/51/200... 36.2 0.005 gb|EU429757.1| Influenza A virus (A/duck/Eastern China/40/200... 36.2 0.005 gb|CY028782.1| Influenza A virus (A/swine/California/T9001707... 36.2 0.005 gb|CY028790.1| Influenza A virus (A/swine/Iowa/1/1986(H1N1)) ... 36.2 0.005 gb|CY028437.1| Influenza A virus (A/swine/Tennessee/7/1978(H1... 36.2 0.005 gb|CY028429.1| Influenza A virus (A/swine/Tennessee/4/1978(H1... 36.2 0.005 gb|CY028189.1| Influenza A virus (A/swine/Wisconsin/30747/197... 36.2 0.005 gb|CY028181.1| Influenza A virus (A/swine/Tennessee/3/1978(H1... 36.2 0.005 gb|CY028173.1| Influenza A virus (A/swine/Iowa/2/1987(H1N1)) ... 36.2 0.005 gb|CY027509.1| Influenza A virus (A/swine/Iowa/2/1985(H1N1)) ... 36.2 0.005 gb|CY027525.1| Influenza A virus (A/swine/Tennessee/8/1978(H1... 36.2 0.005 gb|CY027517.1| Influenza A virus (A/swine/Tennessee/5/1978(H1... 36.2 0.005 gb|CY027309.1| Influenza A virus (A/swine/Tennessee/2/1978(H1... 36.2 0.005 gb|CY027301.1| Influenza A virus (A/swine/Tennessee/118/1977(... 36.2 0.005 gb|CY026493.1| Influenza A virus (A/swine/Tennessee/112/1977(... 36.2 0.005 gb|CY026485.1| Influenza A virus (A/swine/Tennessee/106/1977(... 36.2 0.005 gb|CY026477.1| Influenza A virus (A/swine/Tennessee/105/1977(... 36.2 0.005 gb|CY026461.1| Influenza A virus (A/swine/Tennessee/10/1976(H... 36.2 0.005 gb|CY026453.1| Influenza A virus (A/swine/Ontario/6/1981(H1N1... 36.2 0.005 gb|CY026445.1| Influenza A virus (A/swine/Ontario/3/1981(H1N1... 36.2 0.005 gb|CY026437.1| Influenza A virus (A/swine/Ontario/2/1981(H1N1... 36.2 0.005 gb|CY026421.1| Influenza A virus (A/swine/Tennessee/23/1976(H... 36.2 0.005 gb|CY026301.1| Influenza A virus (A/swine/Wisconsin/2/1966(H1... 36.2 0.005 gb|CY026293.1| Influenza A virus (A/swine/Wisconsin/1/1967(H1... 36.2 0.005 gb|CY026285.1| Influenza A virus (A/swine/Wisconsin/1/1957(H1... 36.2 0.005
gb|EU050105.1| Influenza A virus (A/chukkar/Shantou/2888/2003... 36.2 0.005 gb|CY026141.1| Influenza A virus (A/Wisconsin/301/1976(H1N1))... 36.2 0.005 gb|EU139839.1| Influenza A virus (A/swine/North Carolina/3688... 36.2 0.005 gb|EU139837.1| Influenza A virus (A/swine/Minnesota/37866/199... 36.2 0.005 gb|EU139835.1| Influenza A virus (A/swine/Wisconsin/1/1968(H1... 36.2 0.005 gb|CY025207.1| Influenza A virus (A/swine/Tennessee/37/1977(H... 36.2 0.005 gb|CY025012.1| Influenza A virus (A/swine/Kansas/3024/1987(H1... 36.2 0.005 gb|CY025059.1| Influenza A virus (A/swine/Tennessee/48/1977(H... 36.2 0.005 gb|CY024927.1| Influenza A virus (A/Ohio/3559/1988(H1N1)) seg... 36.2 0.005 gb|CY025004.1| Influenza A virus (A/swine/Arizona/148/1977(H1... 36.2 0.005 gb|CY024996.1| Influenza A virus (A/swine/Wisconsin/663/1980(... 36.2 0.005 gb|CY024988.1| Influenza A virus (A/swine/Tennessee/10/1978(H... 36.2 0.005 gb|CY024980.1| Influenza A virus (A/swine/Tennessee/88/1977(H... 36.2 0.005 gb|CY024972.1| Influenza A virus (A/swine/Tennessee/87/1977(H... 36.2 0.005 gb|CY024964.1| Influenza A virus (A/swine/Tennessee/86/1977(H... 36.2 0.005 gb|CY024956.1| Influenza A virus (A/swine/Tennessee/84/1977(H... 36.2 0.005 gb|CY024935.1| Influenza A virus (A/swine/Minnesota/24/1975(H... 36.2 0.005 gb|CY022972.1| Influenza A virus (A/swine/Iowa/31483/1988(H1N... 36.2 0.005 gb|CY022964.1| Influenza A virus (A/swine/Iowa/1/1987(H1N1)) ... 36.2 0.005 gb|CY022996.1| Influenza A virus (A/swine/Wisconsin/629/1980(... 36.2 0.005 gb|CY022980.1| Influenza A virus (A/swine/Ontario/1/1981(H1N1... 36.2 0.005 gb|CY022956.1| Influenza A virus (A/swine/Iowa/1/1977(H1N1)) ... 36.2 0.005 gb|CY022319.1| Influenza A virus (A/swine/Iowa/1/1985(H1N1)) ... 36.2 0.005 gb|CY022327.1| Influenza A virus (A/swine/Iowa/3/1985(H1N1)) ... 36.2 0.005 gb|CY022335.1| Influenza A virus (A/swine/Iowa/17672/1988(H1N... 36.2 0.005 gb|CY022431.1| Influenza A virus (A/swine/Wisconsin/1915/1988... 36.2 0.005 gb|CY022471.1| Influenza A virus (A/swine/Kansas/3228/1987(H1... 36.2 0.005 gb|CY022479.1| Influenza A virus (A/swine/Maryland/23239/1991... 36.2 0.005 gb|CY022463.1| Influenza A virus (A/swine/Wisconsin/8/1980(H1... 36.2 0.005 gb|CY022455.1| Influenza A virus (A/swine/Wisconsin/661/1980(... 36.2 0.005 gb|CY022447.1| Influenza A virus (A/swine/Wisconsin/641/1980(... 36.2 0.005 gb|CY022439.1| Influenza A virus (A/swine/Wisconsin/2/1970(H1... 36.2 0.005 gb|CY022423.1| Influenza A virus (A/swine/Wisconsin/11/1980(H... 36.2 0.005 gb|CY022415.1| Influenza A virus (A/swine/Wisconsin/1/1971(H1... 36.2 0.005 gb|CY022407.1| Influenza A virus (A/swine/Tennessee/11/1978(H... 36.2 0.005 gb|CY022399.1| Influenza A virus (A/swine/Tennessee/1/1975(H1... 36.2 0.005 gb|CY022391.1| Influenza A virus (A/swine/Ontario/7/1981(H1N1... 36.2 0.005 gb|CY022383.1| Influenza A virus (A/swine/Ontario/4/1981(H1N1... 36.2 0.005 gb|CY022375.1| Influenza A virus (A/swine/Nebraska/123/1977(H... 36.2 0.005 gb|CY022367.1| Influenza A virus (A/swine/Minnesota/5892-7/19... 36.2 0.005 gb|CY022359.1| Influenza A virus (A/swine/Minnesota/27/1976(H... 36.2 0.005 gb|CY022351.1| Influenza A virus (A/swine/Kentucky/1/1976(H1N... 36.2 0.005 gb|CY022343.1| Influenza A virus (A/swine/Illinois/1/1975(H1N... 36.2 0.005 gb|CY022303.1| Influenza A virus (A/swine/Tennessee/82/1977(H... 36.2 0.005 gb|CY022295.1| Influenza A virus (A/swine/Tennessee/79/1977(H... 36.2 0.005 gb|CY022287.1| Influenza A virus (A/swine/Tennessee/65/1977(H... 36.2 0.005 gb|CY022143.1| Influenza A virus (A/swine/Tennessee/64/1977(H... 36.2 0.005 gb|CY022135.1| Influenza A virus (A/swine/Tennessee/49/1977(H... 36.2 0.005 gb|CY022127.1| Influenza A virus (A/swine/Tennessee/31/1977(H... 36.2 0.005 gb|CY022119.1| Influenza A virus (A/swine/Tennessee/21/1977(H... 36.2 0.005 gb|CY022111.1| Influenza A virus (A/swine/Tennessee/19/1977(H... 36.2 0.005 gb|CY022103.1| Influenza A virus (A/swine/Iowa/4/1976(H1N1)) ... 36.2 0.005 gb|CY022063.1| Influenza A virus (A/swine/Tennessee/19/1976(H... 36.2 0.005 gb|CY022071.1| Influenza A virus (A/swine/Iowa/1/1976(H1N1)) ... 36.2 0.005 gb|CY022055.1| Influenza A virus (A/swine/Tennessee/17/1976(H... 36.2 0.005 gb|CY022047.1| Influenza A virus (A/swine/Tennessee/15/1976(H... 36.2 0.005 gb|CY022039.1| Influenza A virus (A/swine/Tennessee/7/1976(H1... 36.2 0.005 gb|CY022031.1| Influenza A virus (A/swine/Tennessee/3/1976(H1... 36.2 0.005 gb|CY021959.1| Influenza A virus (A/New Jersey/1976(H1N1)) se... 36.2 0.005 gb|CY021055.1| Influenza A virus (A/Malaya/302/1954(H1N1)) se... 36.2 0.005 gb|DQ835315.1| Influenza A virus (A/China/GD01/2006(H5N1)) se... 36.2 0.005 gb|EF124198.1| Influenza A virus (A/common magpie/Hong Kong/3... 36.2 0.005 gb|EF124197.1| Influenza A virus (A/house crow/Hong Kong/2858... 36.2 0.005 gb|EF124196.1| Influenza A virus (A/house crow/Hong Kong/2648... 36.2 0.005 gb|EF124195.1| Influenza A virus (A/large-billed crow/Hong Ko... 36.2 0.005 gb|EF124194.1| Influenza A virus (A/white-backed munia/Hong K... 36.2 0.005 gb|EF124193.1| Influenza A virus (A/munia/Hong Kong/2454/2006... 36.2 0.005 gb|EF124192.1| Influenza A virus (A/common magpie/Hong Kong/2... 36.2 0.005 gb|EF124191.1| Influenza A virus (A/common magpie/Hong Kong/2... 36.2 0.005 gb|EF124190.1| Influenza A virus (A/Japanese white-eye/Hong K... 36.2 0.005 gb|DQ923509.1| Influenza A virus (A/swine/Korea/CN22/2006(H3N... 36.2 0.005 gb|DQ923508.1| Influenza A virus (A/swine/Korea/PZ72-1/2006(H... 36.2 0.005 gb|DQ150435.1| Influenza A virus (A/swine/IN/PU542/04 (H3N1))... 36.2 0.005
gb|AY207546.1| Influenza A virus (A/duck/New Zealand/76/84(H3... 36.2 0.005
gb|AY207540.1| Influenza A virus (A/mallard/Stralsund/41-6/81... 36.2 0.005 gb|DQ280259.1| Influenza A virus (A/swine/Wisconsin/238/97(H1... 36.2 0.005 gb|DQ280202.1| Influenza A virus (A/swine/Alberta/56626/03(H1... 36.2 0.005 gb|CY009342.1| Influenza A virus (A/Malaysia/54(H1N1)) segmen... 36.2 0.005 gb|AF494254.1| Influenza A virus (A/India/80(H1N1)) neuramini... 36.2 0.005
emb|AJ410559.1|INA410559 Influenza A virus genomic RNA for ne... 36.2 0.005
emb|AJ410558.1|INA410558 Influenza A virus genomic RNA for ne... 36.2 0.005
gb|CY005748.1| Influenza A virus (A/duck/NZL/76/1984(H9N1)) s... 36.2 0.005 gb|AF250363.2|AF250363 Influenza A virus (A/NJ/11/76 (H1N1)) ... 36.2 0.005 gb|U86145.1|IAU86145 Influenza A virus (A/Swine/Quebec/5393/9... 36.2 0.005 gb|U86144.1|IAU86144 Influenza A virus (A/Swine/Quebec/192/81... 36.2 0.005 gb|U47818.1|IAU47818 Influenza A virus (A/swine/Hong Kong/273... 36.2 0.005 gb|U47816.1|IAU47816 Influenza A virus (A/Wisconsin/3523/1988... 36.2 0.005 dbj|D31946.1|FLANANJ76 Influenza A virus (A/New Jersey/8/1976... 36.2 0.005 gb|M27970.1|FLAHANENJ8 Influenza A virus (A/NJ/8/1976(H1N1)) ... 36.2 0.005
Re: Chinese son likely gave bird flu to father: report
<TABLE cellSpacing=3 cellPadding=0 width="100%" border=0><TBODY><TR><TD class=thanh vAlign=top align=left>VN Calm over Neighbor?s Human-To-Human Bird Flu Transmission Report</TD></TR><TR><TD class=tintop_text vAlign=top align=left>Amid disturbing news that a Chinese man contracted bird flu directly from his son, a Vietnamese health official affirmed the Southeast Asian nation has yet to receive official confirmation from WHO of human-to-human transmission cases in any country.
<TABLE cellSpacing=0 cellPadding=3 width=1 align=right border=0><TBODY><TR><TD> </TD></TR><TR><TD class=Image>Viet Nam has not yet received official confirmation from the World Health Organization about human-to-human transmission of bird flu</TD></TR></TBODY></TABLE>
Dr. Nguyen Huy Nga, who heads the Ministry?s Preventative Health Department, said the World Health Organization only warned the H5N1 deadly strain could mutate into a form able to transmit from humans to humans.
?The Chinese human-to-human transmission case could have happened under rare circumstances due to prolonged exposure to the infected person?, Dr. Nga added. Doctor Nguyen Tran Hien, director of the Vietnamese Central Institute for Hygiene and Epidemiology, also assured no human-to-human transmission case has ever been detected in the country and that infections all stemmed from contact with sick fowls.
But Hien warned the virus is showing signs of transforming into more lethal forms since the fatality rate from H5N1 infection has jumped to nearly 100% from 55% several years ago. So far this year, five Vietnamese are reported to have contracted bird flu, and all have died.
Yesterday, Channel News Asia (CNA) reported that a 24-year-old man in Nanjing ?probably infected his father with the H5N1 strain of bird flu before dying?.
The Singapore-based media corp. said ?the case is one of a handful over the last four years in which the H5N1 virus is suspected to have spread from one person to another?.
The article also quoted an epidemiologist as saying such suspected cases have all been "within the family, among blood relatives".
Since 2003, there have been 373 bird flu infections worldwide with 236 fatalities, 52 of which were in Viet Nam.http://www.saigon-gpdaily.com.vn/Health/2008/4/62586/ </TD></TR></TBODY></TABLE>
"A great deal of effort focuses on splitting hairs between a familial cluster due to a common source (poultry) and clusters due to H2H transmission. This distinction is not significant, since both signal a more efficient transmission,...."
I'm sorry, but I still don't get it. I keep coming back to this transmission argument, and I must apologize to seeming like a dog with a bone.
How can "both signal a more efficient transmission"?
If I have contact with an infected bird and get sick, and my brother contacts the same infected bird and gets sick, transmission is logically the same in both cases. Bird to human, virus into the lower respiratory tract, twice.
And if I have close contact with an infected bird and get sick, and my brother has close contact with me and gets sick, what's the difference? Neither situtation indicates a more efficient transmission. It's still bird virus to human, virus into the lower respiratory tract, twice.
Yes, I agree that H2H clusters are occuring (and that all the media, WHO and government risk management tactics are merely noise); however, I'm yet to be convinced that the clusters are significantly different in transmission efficiency than any other bird-human transmission that we've previously seen.
Correct me if I'm wrong, but all the h2h clusters seen so far involve intimate circumstances: repeated exposure to blood, sputum, etc. There's not been a case of casual contact (such as we regularly see in normal influenza) leading to h2h, yet.
Perhaps we're at the limit of what epidemiology (or tracking cases) can tell us at the moment. Until we see the logarithmic explosion of cases, epi analysis is at a hiatus, a low spot, a log-jam.
Until we get the logarithmic explosion, we need the surveillance, samples and science results that show us the cones are now umbrellas, or the clear genetic story, in layman's tersm, of the changes that will justify our terror.
"A great deal of effort focuses on splitting hairs between a familial cluster due to a common source (poultry) and clusters due to H2H transmission. This distinction is not significant, since both signal a more efficient transmission,...."
I'm sorry, but I still don't get it. I keep coming back to this transmission argument, and I must apologize to seeming like a dog with a bone.
How can "both signal a more efficient transmission"?
If I have contact with an infected bird and get sick, and my brother contacts the same infected bird and gets sick, transmission is logically the same in both cases. Bird to human, virus into the lower respiratory tract, twice.
And if I have close contact with an infected bird and get sick, and my brother has close contact with me and gets sick, what's the difference? Neither situtation indicates a more efficient transmission. It's still bird virus to human, virus into the lower respiratory tract, twice.
Yes, I agree that H2H clusters are occuring (and that all the media, WHO and government risk management tactics are merely noise); however, I'm yet to be convinced that the clusters are significantly different in transmission efficiency than any other bird-human transmission that we've previously seen.
Correct me if I'm wrong, but all the h2h clusters seen so far involve intimate circumstances: repeated exposure to blood, sputum, etc. There's not been a case of casual contact (such as we regularly see in normal influenza) leading to h2h, yet.
Perhaps we're at the limit of what epidemiology (or tracking cases) can tell us at the moment. Until we see the logarithmic explosion of cases, epi analysis is at a hiatus, a low spot, a log-jam.
Until we get the logarithmic explosion, we need the surveillance, samples and science results that show us the cones are now umbrellas, or the clear genetic story, in layman's tersm, of the changes that will justify our terror.
J.
Clusters are more efficientn than sporadic cases. Transmission is not an all or none event.
Re: Chinese son likely gave bird flu to father: report
[Angus Nicoll - Eurosurveillance Weekly]
(1) [AVIAN INFLUENZA, HUMAN, CLUSTERED CASES, CHINA, UPDATES, ESWI] (Yet) another human A/H5N1 influenza case and cluster when should Europe be concerned?
A Nicoll (angus.nicoll@ecdc.europa.eu)
European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
A Chinese report of a case from Jiangsu province of an almost certain son-to-father transmission of avian influenza type A/H5N1 infection was published this week, along with an accompanying comment [1,2].
The source of the 24-year-old son?s infection was not established, but the authors suggest this might have occurred during a visit to a market where there was live poultry [1].
Such a way of acquiring infection (rather than direct or close contact with sick domestic poultry) has been suggested in a number of the few human cases recently detected in China [3].
However, in the case described in The Lancet, contact with poultry was not certain and, despite some retrospective investigations in the market, no H5N1 viruses were detected in birds.
The son eventually died and his 52-year-old father almost certainly acquired the infection while caring for him in the hospital, as was the case in another probable human?to-human transmission in Thailand in 2004 [1,4].
In the recent Chinese cluster, the cases, their contacts and the circumstances of transmission were well investigated epidemiologically and virologically, with over ninety contacts traced.
Control measures were vigorous, with contacts being treated with chemoprophylaxis, as recommended by the World Health Organization (WHO) [1,5].
The rigour of the investigation contrasts with many earlier outbreaks and is praised in the accompanying comment [2,6].
Only two of the contacts developed illness that was compatible with bird flu by symptoms and timing, but both were negative for markers of A/H5N1 infection (i.e. their illness had to be due to another cause) [1].
Although the viruses in the father and son were almost identical, the authors still could not be entirely certain that this was human-to-human transmission [1], because it was impossible to entirely rule out shared or common exposure to infected birds or environmental contamination.
This explanation is commonly considered in the investigations of human A/H5N1 cases and is the reason why attempts to determine the number of person-to-person transmissions have been unsuccessful.
Their results are lists of clusters with varying levels of probabilities [6,7].
Attempts at modelling these clusters have been made [8], but these cannot substitute proper field and laboratory investigations, such as were carried out in the Chinese cluster [1].
However, it would be unreasonable for anyone to still argue that person-to-person transmission of A/H5N1 has never occurred [5].
Indeed, it probably occurs more often than it seems, simply because of the multiple possible routes of exposure in most clusters.
Usually, where birds could be the source, they are assumed to be the source of all human infections [6].
A cause for concern for epidemiologists in these and other recent cases in China (and Vietnam) is the difficulty in identifying the primary source of infection for the human cases.
How did the viruses get from birds into humans?
This could not be determined in Jiangsu and sometimes cannot be done elsewhere [1,3].
It has been suggested that this may partially reflect the success of the impressive Chinese veterinary campaigns to immunise all domestic poultry.
These have been highly effective in reducing outbreaks in birds and hence much of the need for mass culling of birds.
This in turn has eliminated the economic and social misery that follows for the owners, who may not always be compensated in a timely manner.
However, since poultry immunisation prevents disease but cannot eliminate infection in birds, it probably has left A/H5N1 silently transmitting among poultry, and existing in the environment near poultry albeit at low levels [9].
This is probably also making detection and surveillance for human A/H5N1 cases more difficult.
The previous marker of contact with a die-off in poultry in sick humans with atypical pneumonias as a trigger for testing for A/H5N1 has been lost.
Local officials and clinicians in endemic countries find it hard to test for H5N1 in all people with symptoms compatible with human A/H5N1 infection. This is being attempted in Thailand but not elsewhere, probably because of the costs and logistics [10,11].
Human-to-human transmission of A/H5N1 is not new.
Indeed some of the most certain transmissions occurred from patients to health care workers in Hong Kong when A/H5N1 was first observed in humans in 1997 [12].
This latest Chinese report of human-to-human transmission does not change anything.
It fits with the European Centre for Disease Prevention and Control (ECDC) risk assessment (published in 2005 and revised in 2006) and with the WHO Pandemic Alert Phase 3, which allows for occasional human-to-human transmissions to take place [13,14].
Looking broadly at the recent epidemiology and virology of the A/H5N1 influenza continuously reported by the WHO [15], there is nothing of late to suggest that A/H5N1 has changed its behaviour in a worrying manner.
However, an important caveat to this statement is the case of Indonesia, which accounts for more human cases than any other country (15 of the 28 confirmed human A/H5N1 cases reported for 2008 by WHO to 8 April) and which has seen some of the largest clusters of cases in earlier years, with perhaps third-generation transmission [16,17].
Although the detection and investigation of cases has improved in Indonesia, since early 2007 the authorities have stopped sharing human A/H5N1 viruses with the rest of the world through the WHO-managed Global Influenza Surveillance Network (GISN), despite the 2005 International Health Regulations, whose spirit if not wording dictates transparency and ready sharing of data and specimens [18,19,20].
Hence, it is impossible at present to know in any timely manner whether or not the A/H5N1 viruses are changing virologically in that country.
Yet, if a pandemic is to start in any country, the time factor will be of the essence for early investigation and intervention [21,22].
So should European authorities be concerned about individual human A/H5N1 cases and probable transmissions like the one described in The Lancet and another two reported retrospectively from Pakistan [1,23]?
The time has probably come to be less excited about media or confirmed reports of isolated human cases that occur on almost a daily basis in the media and in newsletters from bodies like the Flu Information Centre in China (FIC, http://www.flu.org.cn/en/default.html.
The virus remains highly pathogenic to humans (the most recent review undertaken by WHO still reports a case fatality rate of over 60 percent [5]), so these cases are often personal and family tragedies.
However, sporadic confirmed cases now seem to represent background incidence in countries where A/H5N1 is entrenched in domestic poultry and there is close contact between birds and humans.
Sporadic cases and small clusters like that in Jiangsu are common and, unless A/H5N1 fades away (as some other avian influenza viruses have), the world may remain in the Pandemic Alert Phase 3 (as defined by WHO [14]) for some years.
What European authorities must be concerned about are any ominous changes in the behaviour and the virology of the A/H5N1 viruses in humans, but also in poultry.
In particular, more clusters of human A/H5N1 cases, larger clusters and lengthening chains of transmission which could indicate that these viruses are acquiring pandemic qualities (Pandemic Alert Phase 4 and 5 in WHO parlance [14]).
That has not happened as yet.
If anything, clusters seem to be less common and smaller at present than they were in 2005 and 2006.
However, it has been pointed out that it would be dangerous to assume that because H5N1 has not yet acquired pandemic characteristics it does not have that potential, which is a point also made in the ECDC?s risk assessment [2,13].
Continuing work by international organisations, governments and veterinarians to root out highly pathogenic avian influenza infections from poultry is fundamental.
Where this is not possible in the short and medium term, it means there will be pressure on clinicians and public health authorities in the countries where the virus is endemic, common or simply regularly occurring in domestic poultry.
It is difficult to know precisely which countries are concerned, but notable are Cambodia, China, Egypt, Laos, Indonesia, Myanmar, South Korea, Thailand and Vietnam, and recently also Bangladesh and Pakistan [24].
However, there are also countries like Nigeria, where A/H5N1 was seen in birds but is currently not reported, and other parts of sub-Saharan Africa where veterinary surveillance for highly pathogenic avian influenza in poultry is patchy (although improving following international investment).
Does no signal mean that the virus has gone or rather that there are problems in surveillance?
Wherever the virus is present in poultry and people come into close contact with them, there needs to be continued detection of potential human cases, viral isolation and rapid sharing of virus through GISN and vigorous investigation around the cases to ensure they are only sporadic, and not part of a large or expanding cluster.
Considering the resources deployed in Jiangsu by the provincial and national specialists [1], it can be seen that this will not be easy for poorer countries, certainly not without support from the rest of the world.
Less sophisticated and resource-demanding investigations will probably need to be developed and made sure to be carried out and sustained at least for some years to come.
References
1) Wang H, Feng Z, Shu Y, Yu H, Zhou L, Zu R, et al. Probable limited person-to-person transmission of highly pathogenic avian influenza A (H5N1) virus in China. The Lancet. Early Online Publication, 8 April 2008.
2) Hien NT, Farrar J, Horby P. Person-to-person transmission of influenza A (H5N1). Comment. The Lancet. Early Online Publication, 8 April 2008.
3) Yu H, Feng Z, Zhang X, Xiang N, Huai Y, Zhou L, Human influenza A (H5N1) cases, urban areas of People's Republic of China, 2005-2006. Emerg Infect Dis. 2007;13(7):1061-4.
4) Ungchusak K, Auewarakul P, Dowell SF, Kitphati R, Auwanit W, Puthavathana P, Probable person-to-person transmission of avian influenza A (H5N1). N Engl J Med. 2005;352(4):333-40.
5) Writing Committee of the Second World Health Organization Consultation on Clinical Aspects of Human Infection with Avian Influenza A (H5N1) Virus, Abdel-Ghafar AN, Chotpitayasunondh T, Gao Z, Hayden FG, Nguyen DH, et al. Update on avian influenza A (H5N1) virus infection in humans. N Engl J Med. 2008;358(3):261-73.
6) Nicoll A. Human H5N1 infections: so many cases ? why so little knowledge? Euro Surveill 2006;11(5):74-5. Available from: http://www.eurosurveillance.org/em/v11n05/1105-221.asp
7) Olsen SJ, Ungchusak K, Sovann L, Uyeki TM, Dowell SF, Cox NJ, et al. Family clustering of avian influenza A (H5N1). Emerg Infect Dis. 2005;11(11):1799-1801.
8) Uyeki TM, Bresee JS. Detecting human-to-human transmission of avian influenza A (H5N1). Emerg Infect Dis. 2007;13(12):1969-71.
9) Savill NJ, St Rose SG, Keeling MJ, Woolhouse ME. Silent spread of H5N1 in vaccinated poultry. Nature. 2006;442(7104):757.
10) Olsen SJ, Ungchusak K, Birmingham M, Bresee J, Dowell SF, Chunsuttiwat S. Surveillance for avian influenza in human beings in Thailand. Lancet Infect Dis. 2006;6(12):757-8.
11) Ministry of Public Health, Thailand. Avian Influenza (Bird Flu) Control. Available from: http://thaigcd.ddc.moph.go.th/Bird_Flu_main_en.html
12) Buxton Bridges C, Katz JM, Seto WH, Chan PK, Tsang D, Ho W, et al. Risk of influenza A (H5N1) infection among health care workers exposed to patients with influenza A (H5N1), Hong Kong. J Infect Dis. 2000;181(1):344-8.
13) ECDC. The Public Health Risk from Highly Pathogenic Avian Influenza Viruses Emerging in Europe with Specific Reference to type A/H5N1. June 2006. Available from: http://www.ecdc.europa.eu/Health_topics/Avian_Influenza/pdf/060601_public_health_risk_HPAI.pdf
14) World Health Organization. WHO global influenza preparedness plan. The role of WHO and recommendations for national measures before and during pandemics. Geneva, 2005. Available from: http://www.who.int/csr/resources/publications/influenza/WHO_CDS_CSR_GIP_2005_5.pdf
15) World Health Organization. Situation updates - Avian influenza. Available from: http://www.who.int/csr/disease/avian_influenza/updates/en/index.html
16) World Health Organization. Cumulative number of confirmed human cases of avian influenza A/(H5N1) reported to WHO. Accessed on 8 April 2008. Available from: http://www.who.int/csr/disease/avian_influenza/country/cases_table_2008_04_08/en/index.html
17) Kandun IN, Wibisono H, Sedyaningsih ER, Yusharmen , Hadisoedarsuno W, Purba W, et al. Three Indonesian clusters of H5N1 virus infection in 2005. N Engl J Med. 2006;355(21):2186-94.
18) ECDC. Influenza Virus Sharing ? Interim ECDC Briefing. November 2007. Summary. Available from: http://ecdc.europa.eu/pdf/ECDC_influenza_briefing.pdf
19) World Health Organization. Global Influenza Surveillance Network. Available from: http://www.who.int/csr/disease/influenza/influenzanetwork/en/index.html
20) World Health Organization. International Health Regulations (2005). Available from: http://www.who.int/csr/ihr/en Revision of the International Health Regulations. Full text. Available from: http://www.who.int/gb/ebwha/pdf_files/WHA58/WHA58_3-en.pdf
21) Ferguson NM, Cummings DA, Cauchemez S, Fraser C, Riley S, Meeyai A, et al. Strategies for containing an emerging influenza pandemic in Southeast Asia. Nature. 2005;437(7056):209-14.
22) World Health Organization. Interim Protocol: Rapid operations to contain the initial emergence of pandemic influenza. Available from: http://www.who.int/csr/disease/avian_influenza/guidelines/draftprotocol/en/index.htm
23) 23. World Health Organization. Avian influenza - situation in Pakistan - update 2. 3 April 2008. Available from: http://www.who.int/csr/don/2008_04_03/en/index.html
24) World Organisation for Animal Health. Update on highly pathogenic avian influenza in animals (type H5 and H7). Available from: http://www.oie.int/downld/AVIAN%20INFLUENZA/A_AI-Asia.htm
- http://www.eurosurveillance.org/edition/v13n15/080410_5.asp
A NEW case of human-to-human transmission doesn't prove that H5N1 bird flu is learning to spread among humans, but it reinforces fears that there could be many more undiagnosed human infections in China. It may also point to a potential cure.
Last November, a salesman hospitalised in Nanjing, China, with fever, diarrhoea and pneumonia was given antibiotics for suspected bacterial infection, but tested positive for H5N1 shortly before he died. The next day his father fell ill with a nearly identical virus, and was given plasma from a woman who had received an experimental whole-virus H5N1 vaccine. He recovered (The Lancet, DOI: 10.1016/S0140-6736(08)60493-6).
The month before, an H5N1 patient in Shenzhen also recovered after receiving plasma from someone who had survived the infection, suggesting that antibodies from such survivors are a promising approach to treating H5N1, and should be investigated further.
However, poultry in Chinese markets are required to be vaccinated, and the fact that the Nanjing salesman had visited a live poultry market shortly before he fell ill reinforces fears that many Chinese could be getting H5N1 from vaccinated poultry, which carry the virus but remain healthy. Like the salesman, such people could be misdiagnosed because they have not been near sick birds.
Jeremy Farrar of the University of Oxford's Clinical Research Unit in Ho Chi Minh City, Vietnam, says scientists should study family clusters of H5N1 to learn what allows the virus to infect humans. Clusters in Thailand, Indonesia, Pakistan and possibly Vietnam have involved only genetically related people. Generally, the virus remains hard to catch - none of other 91 people who'd had contact with the salesman or his father were infected.
?The virus is still hard to catch. None of the other 91 people in contact were infected?
This suggests that "there may be a rare genetic predisposition to the virus", Farrer says.
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