China's bird flu mystery
April 6th, 2013
01:03 PM ET

China's bird flu mystery

By Laurie Garrett, Special to CNN

Editor's note: Laurie Garrett is a Pulitzer prize-winning journalist and senior fellow for global health and the Council on Foreign Relations. The views expressed are her own.

This week, millions of Chinese visited family cemetery plots for the annual Tomb Sweeping Festival. They left or burned objects they thought their deceased ancestors could use in the afterlife, including chickens, pigeons and other food delicacies. Mao Zedong banned tomb sweeping because he thought it a decadent symbol of China’s Confucian past. But this year, China’s Communist Party had a different concern for tomb sweepers: Don’t handle live birds for your ancestors, or you just might be joining them in the afterlife.

It’s bird flu.

The emergence of the H7N9 avian influenza, mutated into a humanly infectious form, would be cause for concern even if it were a one-off event in a remote Chinese farm village. After all, this class of flu virus has never before infected, sickened or killed human beings – it’s a bona fide bird flu. But the disease drama now is unfolding in five large eastern China cities with a combined population of 48 million. This is a decidedly urban flu, its human victims identified to date span from ages 4 years to 87, and for most of the cases there is no obvious explanation for how they contracted their infections, or why their loved ones, co-workers and neighbors apparently did not.

Information released to date by Chinese health and agricultural authorities boils down to:

– Four of the flu viruses found in deceased Shanghai, Anhui and Hangzhou patients have been fully genetically sequenced, and those details have been posted on a transparent website for all the world to scrutinize.

– Those flu virologists that have examined the sequences say H7N9 – which for millennia has only infected birds – has now mutated into a mammalian virus. There are stretches of RNA genetic material that are exclusively found in flu viruses that infect mammals.

– But the Chinese insist those thousands of bloated pig carcasses that were floating down Shanghai’s Huangpu River when this outbreak began were coincidental occurrences – the animals did not have H7N9 flu. No satisfactory explanation for the pigs’ deaths has been offered.

– Some pigeons, doves, ducks and chickens caged for sale in the Shanghai poultry markets tested positive for the virus, but showed no signs of illness. Yesterday in Shanghai some 20,000 of them were killed, in hopes of stopping putative spread from birds-to-people.

– There is no indication that H7N9 is spread from person-to-person, or that a lot of Chinese are carrying the virus without outward symptoms of flu.

None of this is making sense.

Looming over all other questions in this outbreak is the Denominator Problem. Typically, when a dangerous disease breaks out in people for the primary time it’s noticed first in hospital emergency admissions, as deathly ill individuals gasp for air. These acute cases are counted, and as their numbers climb it’s possible to get a dangerously distorted view of disease severity. As I write these words, Chinese authorities have reported 16 confirmed cases of H7N9 infection, all critical; six have proven fatal. And no infected-but-mild flu cases or asymptomatic individuals have been identified. So it seems this H7N9 produces life-threatening illness in 100 percent of infected humans, killing nearly half of them.

But those numbers must be wrong. When H1N1 swine flu broke out in Mexico authorities were terrified by a sudden wave of critically ill and dying pneumonia patients that swamped emergency rooms all over the country. It seemed that “the big one” was upon them – an influenza so lethal and contagious that it might sweep over humanity with devastating result. But I warned at that time about the Denominator Problem: How many Mexicans had mild or frankly unnoticed infections? As it turned out, the denominator was enormous, so that for every seriously ill swine flu case there were thousands of mild and asymptomatic infections. What had initially seemed a terrifying specter turned out to be a very contagious, but wimpy, flu.

So far, China has not provided any genuine denominator. This is most likely due to one of three things.

First, the actual blood test used to identify infections is overly specific, missing infections. So infected, but not ailing, people that are controlling the viruses in their bodies so well that very few microbes are present in each tested droplet, may be missed. And long-dead pigs may no longer harbor sufficient live virus in their rotting blood to be picked up in the tests. Details of the testing method(s) used by health and agricultural investigators have not been released, though scanty reports from Xinhua, the government news agency, indicate PCR nucleic acid amplification has been deployed. PCR assays are notoriously prone to contamination, and are only as reliable as the investigators’ choice of gene sequences to study. If the assay is designed to look only for rust colored bricks the investigator may not see the entire building.

The most recent announcements from WHO and Chinese authorities indicate most of the “testing” of close contacts of ailing or deceased H7N9 patients has featured interviews, not actual blood tests. Individuals are asked by health department investigators whether they have experienced the symptoms exhibited by the 16 known patients: difficulty breathing, high fever, extreme fatigue, dizziness, profound muscle aches…And unless the questioned individual is sick at the time of interview, the public health official must rely on self-reporting.

There are three reasons why many Chinese might choose to hide an illness if it weren’t obviously life-threatening. First, during the SARS epidemic the People’s Liberation Army took control of most patient care outside of the initial Guangzhou outbreak of December 2002, placing all fever patients in confinement. Those not held in military facilities were quarantined for weeks either inside key hospitals or their homes. For some the isolation and fear was so great that they leapt from high story windows to escape, or bribed their ways out of confinement if they were wealthy enough to do so.

Though the government has announced that patient care for H7N9 should be free, healthcare can be bankrupting in China. The reported $1,600/day cost of H7N9 care may seem small compared to an American hospital bill, but it’s a daunting sum for many Chinese. Even in wealthy Shanghai the GDP per capita in 2012 was $9,100 – a week’s hospitalization would wipe out a year’s income.

During the SARS epidemic I spoke with many patients’ families that had been assured the government would cover the costs for their loved ones’ care, but wept openly as they described doctors and nurses demanding huge payments, or else. Typically, the threat was without more money, your loved one will simply be left on his own in isolation, without medicine, without food. These stories circulated widely in 2003, and resonate today.

A final, perhaps more complicated reason family, co-workers and friends of the 16 H7N9 sufferers may not admit to experiencing flu-like symptoms is China’s air pollution. I was in Beijing in January when the particulate levels soared to levels 20 times above the U.S. EPA top allowable air pollution index. During that time my eyes watered, throat burned, head ached, I coughed and I felt tired and depressed. March of this year witnessed the worst March air pollution in Chinese history, according to government officials. It would be easy to miss a mild flu when feeling lousy, and flu-like, day after day, thanks to the pollution.

This Denominator Problem is the key to understanding what is going on. Essential to assessing the severity of the disease, valid determination of mild infections is the only way to figure out whether person-to-person transmission is taking place. For example, in March three members of the same family in Shanghai came down with critical cases of pneumonia, and all were hospitalized. Two of them died – an elderly father and his middle-aged son. The third survived his ordeal. Only the deceased father tested positive for H7N9, according to Shanghai health authorities. We are left to wonder at the profound coincidence that both of the deceased’s sons had pneumonia at the same time as he, but from some other, unknown cause. If Chinese test methods are correct, the coincidence is real. If the test approach is mistaken, this family more than likely experienced human-to-human transmission of the H7N9 virus.

My Council on Foreign Relations Colleague Yanzhong Huang argues that, “the post-Mao policy process has witnessed a shift from ‘bandwagon’ to ‘buck-passing,’ which encourages strategic disobedience and policy shirking. For this reason, China’s response to public health emergencies may continue to be bedeviled by lingering problems of under-reporting, misinformation, and inaction.”

On March 19 a Chinese government agency issued the following statement, which ended up on the social media site, Weibo: “The Shanghai Huangpu River dead pig incident is already being dealt with effectively. Related follow-up coverage should follow Xinhua wire copy and information issued by authoritative local departments. The media are not to send journalists to Jiaxing or similar locations to investigate, nor to sensationalize or comment on the issue.”

A few years ago I wandered through an old cemetery in Nova Scotia, and realized too many graves bore death dates for 1918. It was, of course, the Great Influenza that felled these souls. We can only hope that next year’s Tomb Sweeping Ceremony doesn’t find a disproportionate number of Chinese graves bearing year-of-death etchings for 2013.

Topics: Health

soundoff (55 Responses)
  1. Sardonic.veritas

    Are you purposefully not mentioning the oft criticized zealousness off China's containment measures of H1N1?

    No doubt, China dropped the ball with SARS a decade ago, but if how they handled H1N1 is still the precedent, then you should wait for more data before you publish personal conjecture.

    April 6, 2013 at 2:21 pm | Reply
    • Ruby

      If you actually read the article you will find:
      "...during the SARS epidemic the People’s Liberation Army took control of most patient care outside of the initial Guangzhou outbreak of December 2002, placing all fever patients in confinement. ..."

      Perhaps you missed that part, hum?

      April 6, 2013 at 3:34 pm | Reply
      • Fiona

        Of course he missed it, because he didn't bother reading more than a couple paragraphs, if that. Too many people here spout off after reading only the summary.

        April 6, 2013 at 4:45 pm |
  2. A.L.GTCF

    So...your opinion article-seems to be based upon a whole lot of speculation and very few (if any actual facts/numbers). Why is this even published by CNN?

    April 6, 2013 at 2:57 pm | Reply
    • Ruby

      "...your opinion article-seems to be based upon a whole lot of speculation.."

      That's why it's called opinion.

      April 6, 2013 at 3:37 pm | Reply
      • MrSmith

        You have to remember Ruby, the Chinese have a difficult time mastering the English language. There are those within the Great Firewall that follow our news channels daily to post and pursuade public opinion. I suspect you are trying to rationalize with such folks. Good Luck on that.

        April 6, 2013 at 4:02 pm |
  3. JAL

    LOL rooster...

    April 6, 2013 at 3:31 pm | Reply
    • JAL

      Anyway, lets not lose focus on China's core value: LABOR. China is interested in fighting poverty at home and abroad. It is their indicator. It is their beacon. Never lose sight of this, when talking about China or you will stop making sense. Moreover, there are things we can learn from them and things they can learn from us. Bottom line: they are an ally in the poverty fight.

      April 6, 2013 at 4:08 pm | Reply
      • JAL

        The thing about fighting poverty, and this makes the old-schoolers stomach churn, is that it requires a large amount of grace. We must be responsible people to gain confidence in the fight against poverty. I am not the one who needs the convincing, as I have been saying to get the US unemployment rate to at least 6.5% right now.

        April 6, 2013 at 5:28 pm |
      • sickofitall

        Uh, China is NOT an ally in any way . They're a trading partner, and not a very beneficial one from an average Americans position. Remember Korea, Vietnam? Who do you think was helping them, the " communist fairy"????
        You guys keep on buying your made in china wal-mart crap.

        April 6, 2013 at 8:32 pm |
  4. Spamzilla

    you can make $744 selling flu vaccines online for just 2 hours per day!
    See all the latest in you spambox!

    April 6, 2013 at 4:09 pm | Reply
  5. Fiona

    Having spent enough time in China to know I never want to return, I do not trust any "official" reporting that comes from that government. Since pigs are the perfect Petri dish for viruses, it is logical to assume that it is more than "coincidence" that thousands of unexplained dead pigs floating down a river coincided with the emergence of a new, deadly virus strain in humans. It is very interesting - and quite believable - to read that Chinese might hide illness out of fear, of the government and of incurring debt. I am disgusted, but not at all surprised, to learn that medical and hospital staff demanded bribes for minimal care in the last outbreak.

    China is downright scary, in so many ways. It is a society on the brink of anarchy.

    April 6, 2013 at 4:54 pm | Reply
    • xiu

      you just need to trust your "official" media. Obviously, do you think whether you are willing to go to China "again" would make sense? You should not use "return", instead of "go to AGAIN"

      April 6, 2013 at 7:03 pm | Reply
      • Beefburger

        "Return" is used correctly, you need to study English more better Paco.

        April 6, 2013 at 11:13 pm |
  6. Kurt Brindley

    Reblogged this on Kurt Brindley and commented:
    The best write-up I've seen yet of the H7N9 drama going on in China.

    April 6, 2013 at 5:43 pm | Reply
    • he ming

      This Denominator Problem is the key to understanding what is going on. True! if her descriptions are not understatements of the relevant situation is China, though China has made some progress on reporting.

      April 14, 2013 at 4:16 am | Reply
      • he ming

        (mistyped ... re-POSTING) This Denominator Problem is the key to understanding what is going on. True! If her descriptions are not understatements of the relevant situation in China. Though China has made some progress on reporting

        April 14, 2013 at 4:23 am |
  7. LCB Editors

    Reblogged this on Learn Chinese Business and commented:
    CNN has a good piece on this fast-emerging story, scary stuff. We'll refresh as more details become available!

    April 6, 2013 at 5:45 pm | Reply
  8. Dan, Tx

    A science-based article would be helpful. Someone's personal speculations are not helpful. This article was no more helpful than the official Chinese version.

    April 6, 2013 at 6:02 pm | Reply
  9. Harangue birds? They were burning LOVE BIRDS? What the idea that it'll be a cooked birds corpse in the afterlife? That makes no sense. What is this I don't even...

    April 6, 2013 at 6:22 pm | Reply
    • Harangue

      Live birds, not love, darn.

      April 6, 2013 at 6:23 pm | Reply
    • Fiona

      Read it again, and think this time. The birds were lumped in with "other food delicacies." Therefore, it is logical to assume the birds were slaughtered (in China you generally buy meat birds live) as food, then prepared, then burned as food offerings for the dead. The treatment of animals in China is horrific, but there would be no practical reason to burn birds alive for a tomb sweeping ceremony.

      April 6, 2013 at 6:51 pm | Reply
    • Boo

      They leave delicacies and burn paper objects. Just poor sentence structure on the author's part. I know because I've gone tomb sweeping before.

      April 7, 2013 at 3:26 am | Reply
  10. xiu

    so, what the sense you could make by writing such article?No matter how serious the flu should be in China, does it have anything to do with you, American, who should live thousands thousands miles away from China.........

    April 6, 2013 at 6:56 pm | Reply
    • FGS

      What? And Chinese don't travel? I know many Chinese that travel back and forth frequently. This isn't North Korea.

      April 6, 2013 at 7:13 pm | Reply
    • Frankhy

      Are you serious? Have you no idea whatsoever about how epidemics work? FYI, epidemics don't care about stopping at borders. Or the Chinese believe that viruses obey the Government and will show up to apply for a visa before jumping to Chinese travellers going abroad or foreign visitors to china returning home, or – since this virus evidently affects animals, that no animals cross borders?

      April 7, 2013 at 1:42 am | Reply
  11. ccw

    this article is junk....maybe the author should have contacted a few virologists

    April 6, 2013 at 8:24 pm | Reply
    • nanana

      scared somehow?

      April 9, 2013 at 2:35 am | Reply
  12. sickofitall

    Figures this H1N1 and all its later mutations is happening in China. Wow, what a cesspool of living waste. What a poverty ally. I think I'll pay a little more and buy something made from MY OWN PEOPLE!!!!!!!!

    April 6, 2013 at 8:41 pm | Reply
  13. JW

    I stopped reading when seeing Shanghai's GDP per capita in 2012 quoted in this article is $9100 which is way below the official number $13.4K. How can I trust what the author says given that she could not even make such a simple number right?

    April 6, 2013 at 10:18 pm | Reply
    • Beefburger

      For the same reason that there is nothing wrong with the "official" air quality in Shanghai.

      April 6, 2013 at 11:16 pm | Reply
  14. orclover

    the flu of 1918 that killed 100 million people in 14 months came from a swine reservoir. It was found as passive but present in birds, but sickened and killed swine. It then passed to a farmer in kansas, hit a troop transport train in Leavenworth Ks, headed to New York, on a ship to europe and wiped out a spring offensive that the germans had planned in 1918. It killed very few on its journey over the sea and through the armies of europe but evolution dictated that every human it passed through it also strengthened it to an optimum virality . It then returned to boston as a monster in sept 1918. H7N9 is likely a swine flu but unlikely to be the ONE.

    April 6, 2013 at 11:05 pm | Reply
  15. Beefburger

    I think I saw this story on an episode of Season 2 of ReGenesis. Call David Sanstrom at NORBAC pronto!

    April 6, 2013 at 11:18 pm | Reply
  16. williamdavidson

    In addition to the three members of the same family, two diagnosed with 'severe pneumonia' (one dying), and the other with H7N9 (also a fatality), there is also a four year old boy who was diagnosed with mild H7N9, whose mother is one of the patients in a critical condition.

    It's possible they all became infected from an environmental source, such as undercooked pork or chicken, but it seems more likely that the virus was transmitted between them.

    Another two cases have been reported since the article was written. You get the impression that it's not just the patients who are being 'drip fed'.

    April 7, 2013 at 6:39 am | Reply
  17. Bear

    I cant believe this! They burn poor birds a stake? I never want to go to China! Its my worst nightmare!

    April 7, 2013 at 9:54 pm | Reply
    • Linda

      Hi.Bear. Don't belive this article. I am Chinese, In tomb sweeping day, we burn just paper:such as paper clothes, paper shoes, maybe paper bird, or even paper iphone. I think the author just delibrated to not mention the word PAPER. It is hard to respect his behavior.

      April 8, 2013 at 10:15 am | Reply
  18. Richard

    Check out the 2013 H7N9 Influenza A Outbreak link on the IRD home page to learn more about possible sequence determinants of human adaptation of this avian flu strain – .

    April 10, 2013 at 5:54 pm | Reply
  19. Sherri Kocab

    Type A flu virus is constantly changing and is generally responsible for the large flu epidemics. The influenza A2 virus (and other variants of influenza) is spread by people who are already infected. The most common flu hot spots are those surfaces that an infected person has touched and rooms where he has been recently, especially areas where he has been sneezing.;*`'

    Brand new brief article on our very own web blog

    June 20, 2013 at 11:43 pm | Reply

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