Bird flu's China syndrome

China has just registered its 26th known case of bird flu and its 17th death. I emphasize known, because in a country of over 1.3 billion that has not been able to eradicate this virus from its vast poultry population, it would seem the real number is probably quite a bit higher. But what I want to return to about this case is something I have discussed before regarding the Chinese cases (and pertains to most of the other reported cases as well), but is starkest for the Chinese reports. But first, the pertinent part of the case:

China's first human case of bird flu in six months shows that the virus is lingering in the nation and isn't always preceded by reports of diseased poultry, a World Health Organization spokeswoman said.

A man from the eastern province of Jiangsu died yesterday of the H5N1 strain of avian influenza, the state-run Xinhua News Agency said today, citing the local health department. The 24- year-old hadn't been in contact with dead poultry and local animal husbandry and veterinary officials found no evidence of an outbreak, Xinhua reported.

"It shows that the H5N1 virus is still circulating in China," said Joanna Brent, a WHO spokeswoman in Beijing, in a telephone interview today. "This is another case that hasn't been forewarned by an outbreak in poultry, and it shows that we need to strengthen animal surveillance strategies."

The case highlights China's struggle to eradicate the H5N1 virus more than a decade after it was discovered in a goose in the southern province of Guangdong. Since then, it has spread to 60 countries across Asia, the Middle East, Africa and Europe. World health officials say the virus may spark a pandemic if it mutates and begins spreading easily among humans.(Jason Gale, Bloomberg)

So here are the elements. This case, like many others in China, didn't have overt exposure to sick or dying poultry, the favorite explanation for cases and the only one the Indonesians seem to recognize (they always find some sick birds in the vicinity, even if the "vicinity" means several football fields distant). Chinese scientists have seen this before and in June they published a paper on six such cases which we discussed at some length.

The gist of the earlier story was this. Detailed histories taken the six cases with no evidence of contact with sick poultry did find a wet market connection with all of them. These cases came from six different cities in 5 different provinces:

None of the 6 case-patients had known direct contact with poultry that were sick or died of illness. Two patients (case-patients 1 and 3) had no identified potential exposures except for visiting a wet poultry market during the week before illness onset. Four other case-patients visited wet markets, although other exposures could have potentially led to virus transmission. Case-patient 2 was an egg seller and could have also been infected by contact with fecally contaminated eggs. In 2005, influenza A (H5N1) virus was isolated from eggs brought to China by travelers from Vietnam (11). Case-patient 4 could potentially have been exposed to the virus through preparation of freshly slaughtered chickens purchased at a wet market. Case-patient 5 could have been exposed to the virus by visiting his parents' home, which had healthy backyard poultry outside, or by transporting eggs. Case-patient 6 could have been exposed to the virus at home, when his wife prepared a freshly slaughtered chicken purchased from a wet market. No epidemiologic evidence suggested human-to-human transmission of influenza A (H5N1) associated with the urban patients. (Yu et al., Emerging Infectious Diseases)

There are two things about this that stood out to us then and which the latest case also highlights. We don't know how many randomly selected people in these huge urban areas that didn't get sick would also have given a history of visiting a wet market. And even if visiting a wet market (or something else) was the place where the victims encountered the virus, the big question, not just for the Chinese cases but for all the cases is this: Why just these people and not others?

There is undoubtedly a massive reservoir of high path H5N1 virus in China, as there is in Indonesia. Even if only a small fraction of cases are reported it wouldn't account for the paucity of cases. All attempts so far to find mild or inapparent infections for which the clinically apparent cases would be the tip of the iceberg (and this is the rule with infectious diseases) have been unsuccessful. That's good and bad. The good part is that it suggests the virus doesn't infect humans easily. The bad part is that the current case fatality ratio of over 60% is much closer to being the truth than any of us want to think.

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H5N1 stands alone as to threat potential...and it is the threat potential alone that requires a war footing...in my opinion.

With a potential requirement of 50% of the population requiring antibiotics and oral electolytes and other supportive therapy...where is the surge production capacity?

...or are they going to tell us that we don't need antibiotics like they told the nurses with SARS that they didn't need N95 masks.

"The bad part is that the current case fatality ratio of over 60% is much closer to being the truth than any of us want to think."
Government policy all over the world appears to promote the concealment and distortion of health information and scientific analysis regarding bird flu for political purposes.
The Chinese government informed a virologist in Hong Kong he could not release information he had regarding bird flu strains, because that information was a state secret.
This type of governmental response is dangerous, since a fatality rate of 60%, if it remains constant during a pandemic, would cause millions of deaths. In some poor countries there would even be the danger of contamination from the accumulation of dead bodies, which would increase the death rate, since there might not be any way to adequately dispose of the bodies in these countries. In Indonesia they sometimes throw the dead infected birds into the rivers. Would they do the same with the bodies of bird flu victims during a pandemic?
The fatality rate during the Spanish Flu Pandemic of 1918 was about 2 or 3%. And millions died. In some American cities, bodies of victims were placed in mass graves, since there was not time to bury each victim individually. There were not enough caskets, or undertakers. You should take your local undertaker out for coffee, and make good friends with him or her, just in case.
Can you imagine the destruction of a pandemic with a 60% fatality rate? A Russian doctor recently announced there is still a high probability of a bird flu pandemic soon, as the virus continues to mutate.
Thanks to world government policy, a pandemic may arrive sooner than it would otherwise.

Today also marks day 6 since the endoGeneva for the WHO. Guess what? We are all saved because of the conference. How do I know? Because there aint a story out there from Indonesia. Bird flu just dropped off the media screen. Watch for the gambit....they'll try to get us to buy into their program with a whole new sudden surge of cases that finally get reported.

Vaccines? Vaccines? The West says you don't need no steenkin' vaccines. But then again, you don't need them because all of a sudden there are zero news stories on it there.

By M.Randolph Kruger (not verified) on 04 Dec 2007 #permalink

People don't get tested for H5N1 unless they die, and even then many do not get tested, so how many cases thye might have had is anyones guess.

In China's case, for them to report 1 case, it usually means they are aware of many more. How many? Who knows.
They have learned from SARS though, always cover a lie with a sprinkling of truth.

H5N1 has been around in China for so long now, I would not be surprised if many people did not have immunity from prior exposure.

While fatality rate is an exciting number, you first have to know how many people get infected, and for that we have no idea, since no one routinely tests people that come down with respiratory illness. The number has all the credibility of governments GDP and CPI numbers

The other key is how easy is it to transmit from person to person. If it does not spread quickly in a highly populated country like China, those of you in Kansas have not much to fear.

We know that back in 2005/2006, China embarked on a massive program of innoculating chickens and ducks in an effort to erradicate the H5N1 virus.

We also know of documented instances in Europe in which epidemiologsts have found living wild ducks with the H5N1 virus; and the ducks were not showing any signs of being sick.

Also, there are reported instances of a similar nature in Indonesia and Vietnam.

1.) What is the possibility in China that because of the innoculations, the H5N1 virus has mutated in poultry so that the chickens and ducks are not dieing or showing outward symptoms of being sick?

2.) August 20, 2004 the Chineese Goverment discovered the H5N1 virus in Pigs. This is probibly an extremely large secondary reservoir for the virus in China. Have any of these human cases eaten pork or been around pigs? [http://news.bbc.co.uk/2/low/asia-pacific/3583856.stm)]

3.) Do any of these human cases have cats or dogs or is it possible they were infected through houseflies in the wet markets?[http://www.worldpoultry.net/ts_wo/news/id2205-23210/houseflies_can_tran…]

By Mel Miller / a… (not verified) on 05 Dec 2007 #permalink

Mr. Miller

You questions and speculations are very interesting. Perhaps the further analysis in evolutionary genetics to prevent the cultured animals becoming naive and turning into vector of virus or mutated virus is a relevant direction for solving bird flu crisis.

The human intervention such as adoption of vaccines need to be reviewed very careful with indepth research. To avoid abuse as antibiotics.