Avian Flu Pandemic?

[Rolfe]

It was the casual way the radio announcer said that H7 wasn't likely to be a serious threat to human health as "only one vet hes died" that really reassured me....

Rolfe.

 

[Skeptic Ginger]

We've had the same sort of scaremongering right here in the U.S. ...New Jersey to be exact.

http://www.app.com/apps/pbcs.dll/article?AID=/20060430/NEWS03/604300436/1007

Those reporters just can't contain themselves. You think they just can't wait for the real pandemic?

 

[Skeptic Ginger]

It was the casual way the radio announcer said that H7 wasn't likely to be a serious threat to human health as "only one vet hes died" that really reassured me....

Rolfe.

It was in British Columbia. There was concern the H7 would become the next pandemic. Quite a few people near the chickens got eye infections. But then nothing else happened. All you are seeing now is more attention being paid to something that has been around a while already.

H5N1 is the real one to worry about here. It is replicating by the gazillions and only needs a couple mutations to begin spreading among humans, and it's hopeless to control it or monitor for those first contagious human cases in the countries it is now entrenched in.

 

[Yllanes]

It was the casual way the radio announcer said that H7 wasn't likely to be a serious threat to human health as "only one vet hes died" that really reassured me....

Rolfe.

That reminds me of an F1 race that was playing on a bar a couple of years ago. There was an accident during a pit stop and one man died. 'Fortunately', the announcer said, 'he was not a pilot'.

 

[SteveGrenard]

I saw the ads tonight the lst time for a made for TV movie from ABC which will air
on May 9th called Fatal Contact. If we didn't have scare mongering before on any level, this takes it to a new one. The scene shown on TV tonight was about 20 million dead or something like that.

LOS ANGELES, CA, United States (UPI) -- ABC has unveiled its top-secret, made-for-TV movie about avian flu for the May sweeps rating period.

'Fatal Contact: Bird Flu in America stars Stacy Keach, Joely Richardson, Ann Cusack and Justine Machado in a tale about what could happen if the virus starting moving among residents of the United States, the New York Post reported Tuesday.

Co-producer Diana Kerew said they kept the film under wraps because of 'its topicality.'

'The world changes very quickly, and we wanted to make sure at the point we were ready to unveil (the film) that we were accurate and up-to-date,' she told the Post.

Although the film airing May 9 is fictional, 'We`ve included a lot of information we believe people need to know,' co-producer Judith Verno said.

Sounds like the same paradigm they use for The Da Vinci Code ... it's fictional but it isn't.

 

[Dymanic]

I still can't believe how so many people use what's presented in mainstream media (or, even worse, made-for-TV-movies) as the basis for evaluating the seriousness of this threat, and I can't fathom the logic behind the conclusion that the threat is less real because the issue has been exploited by sensationalists. What counts isn't what reporters think, and it certainly isn't what movie scriptwriters think. What counts is what the experts in the relevant fields think, and pretty much all of them are scared stiff.

I don't spend much time watching TV. I haven't seen previews for "Fatal Contact", and don't plan to watch it. My guess is that made-for-TV-movie writers tend to make the (rather safe) assumption that for their audience, nothing happening outside the U.S. is very important, so the "20 million dead" refers to deaths in the U.S. alone. That would be a high estimate, but not worst case, especially when social disruption is factored in.

Twenty million dead globally is not even close to a worst-case projection; the Spanish flu pandemic killed more people than that (five times that many, by some estimates) -- and that was with a case fatality rate at around 2.5 percent. So far, the CFR with H5N1 has been about twenty times higher than that, and some very well respected virologists and epidemiologists have therefore ventured estimates WAY higher than twenty million for a H5N1 pandemic. Although most preparedness plans are based on models which use the 2.5% rate (or something close to that), the virology doesn't support it; using such a rate is really based on two things: the assumption that the aquisition of efficient human-to-human transmissibility can (for unknown reasons) be expected to be accompanied by a significant drop in virulence -- and because anything much higher than that is just impossible to plan for anyway.

 

[Skeptic Ginger]

... What counts is what the experts in the relevant fields think, and pretty much all of them are scared stiff.....

I, for one, think we are on the verge of the next "big one" given the few numbers of mutations needed for H5N1 to adapt to humans. But take that fear and turn it into educating yourself on the basics of viral transmission. Hand washing, some common sense infection control measures and we can protect ourselves. You may have to keep the kids home and quit buying any food that you eat without proper washing, but it is not an impossible task.

The big error I see right now is people are wearing masks but not covering their eyes. H7N3 and H7N7 are giving people eye infections. Flu virus most likely can enter through your eye. Tears drain right down to the back of your throat where flu can take hold. So plan on using a face shield for close contact with people, not just a nose/mouth covering mask.

It's a virus, we know how it is transmitted, we should be able to break the chain of transmission with science and meticulous care in what we do. It'll be a bit of a pain, but not impossible.

 

[SteveGrenard]

I, for one, think we are on the verge of the next "big one" given the few numbers of mutations needed for H5N1 to adapt to humans. But take that fear and turn it into educating yourself on the basics of viral transmission. Hand washing, some common sense infection control measures and we can protect ourselves. You may have to keep the kids home and quit buying any food that you eat without proper washing, but it is not an impossible task.

The big error I see right now is people are wearing masks but not covering their eyes. H7N3 and H7N7 are giving people eye infections. Flu virus most likely can enter through your eye. Tears drain right down to the back of your throat where flu can take hold. So plan on using a face shield for close contact with people, not just a nose/mouth covering mask.

It's a virus, we know how it is transmitted, we should be able to break the chain of transmission with science and meticulous care in what we do. It'll be a bit of a pain, but not impossible.

Hmm...according to this report we know darn little about how the disease is spread....it would seem so far breaking transmission by destroying infected birds and vaccinating others seems to be working.

Bird flu threat abates

15 may 06

THE region where the deadly bird flu first erupted in 2003 has reported no new human cases this year, leading health officials to speculate the virus may not be with us indefinitely.

The New York Times reports that the virus H5N1 hasn't been reported in any part of South-East Asia among humans during the past 12 months, nor in poultry for the past six months.
That is the region where its first avian and human casualties were recorded.

The newspaper quotes Dr David Nabarro, the UN's chief pandemic flu co-ordinator, as saying: "In Thailand and Vietnam we've had the most fabulous success stories."

Dr Nabarro stopped short of saying the virus was dying out, adding that he was "cautious in interpreting these shifts in patterns" because too little was known about how the disease spread.

The report also stated that birds migrating from Africa to Europe during the northern spring had not so far carried the H5N1 virus into Europe.

Since bird flu appeared in 2003, more than 100 people have died worldwide, and health analysts say that all of them died after coming into contact with birds.

This has led to the belief that the virus has not yet mutated to cause human-to-human infection.

http://www.heraldsun.news.com.au/printpage/0,5481,19135388,00.html

Here is the original report from the Times today:

http://www.nytimes.com/2006/05/14/world/asia/14flu.html?_r=1&oref=slogin

 

[Skeptic Ginger]

The trouble with opinion pieces is they are opinions not conclusions based on evidence. One can say these cases have or haven't occurred. That would be a conclusion based on evidence. To say what that means would be opinion. So, don't confuse the above report with a authoritative statement of risk.

The season for specific wild bird species to return to Europe from the areas in Africa with widespread outbreaks is now over for the season. That makes things look quieter. The weather apparently is typical for flu outbreaks to abate. So a lull in cases by no means indicates the disease is going away.

The first known human case of H5N1 was actually in Hong Kong in 1997. It then was not seen for a year and it was a few more years before more human cases occurred. If it was going to disappear, it would have disappeared then.

Then of course there are today's headlines:

One million birds culled in Romania after bird flu outbreak

Indonesian tests confirm five people from one family died of bird flu

What I have seen is a steady report of human cases sort of trickling along. We are well past 100 deaths so the above report is rounding down there. I see no change for better or worse. The probability still goes like this:

Pro Pandemic:
Virus readily mutates, only needs a few changes to become adapted to specific human tissue that would allow person to person communicability. Continual human infections provide the selection pressure for those changes.

Anti-pandemic:
H5 has not become a human pathogen in the past.

I give it 90:10 odds for the pandemic.

Official culture confirmed cases and death count to date: 208 cases/115 deaths for a 55% fatality rate.

 

[SteveGrenard]

Here is the source and country breakdown of the figures you cite for the past near 3.5 years:

Cumulative Numbers between 2003-2006 of confirmed human cases of
avian influenza A / (H5N1) reported to WHO, as of 12 May 2006, are as
follows:

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2006_05_12/en/index.html

Country / total cases / deaths / case fatality rate (percent)

Azerbaijan / 8 / 5 / 62.5
Cambodia / 6 / 6 / 100.0
China / 18 / 12 / 66.7
Djibouti / 1 / 0 / 0.0
Egypt / 13 / 5 / 38.5
Indonesia / 33 / 25 / 75.8
Iraq / 2 / 2 / 100.0
Thailand / 22 / 14 / 63.6
Turkey / 12 / 4 / 33.3
Viet Nam / 93 / 42 / 45.2

Total / 208 / 115 / 55.3

 

[Bowser]

Official culture confirmed cases and death count to date: 208 cases/115 deaths for a 55% fatality rate.

55% fatality rate, as I understand it, in people who for the most part received fairly sophisticated medical treatment. If there is a high enough case rate, ventilators and other medical aids will not be available. I would expect a pandemic fatality rate, if based on one of the more virulent h5n1 strains, to be significantly higher.

 

[casebro]

But that 208 cases is only the most severe ones, that required hospitalisation. Hardly ever any mention of how many 'neighbors' had mild cases. Just an occassional hint of 'testing for antibodies' in general populations, so we really don't know any ratios/percentages.

 

[Bowser]

Not quite, casebro. The only "evidence" that I'm aware of that there have been milder cases is based on a questionnable survey. As far as I know, the testing data that has been released has not identified an asymptomatic or mild population. h5n1 in humans is a disease of deep in the lungs where, fortunately, it is more difficult to pass along to others. So right now, everything points to a higher mortality rate in the absence of extreme medical intervention or other short supplies.

 

[casebro]

I don't know where this data fits in: http://www.recombinomics.com/News/02240602/H5N1_Korea_Antibodies.html

but it could be interpreted that : Of 318 workers who handled (killed) birds in a high-risk situation, only 1% got the disease subclinically, and none needed health care. With NO deaths.

And a quote from there: "A serious survey on antibody levels in contacts of H5N1 patients and people in areas of high incidence of H5N1 detection is long overdue,"

 

[SteveGrenard]

Reuters alertnet, 18 May 2006:

http://www.alertnet.org/thenews/newsdesk/JAK28830.htm

Pigs have tested positive for bird flu in the same village on Indonesia's
Sumatra island where 5 people have been confirmed infected with the H5N1 avian influenza virus, a minister said on Thursday.

The incident, involving up to 7 family members, 6 of whom have died, has
raised alarm around the world because authorities cannot rule out
human-to-human transmission.

But the World Health Organization and Indonesian health officials had been
frustrated by the lack of evidence pointing to a source of the virus,
usually infecting poultry. WHO confirmed on Wednesday that 5 members of the family had contracted H5N1 and tests on a 6th were pending.

more details at above URL

 

[Dymanic]

Hmm...according to this report we know darn little about how the disease is spread

What we know darn little about is how the virus, in its present form, spreads from birds to humans. We know quite a bit about how influenza viruses in general spread from one human to another, but so far, H5N1 hasn't done that to any appreciable degree. If begins doing so, questions about how it spreads from birds to humans may remain, but they are likely to seem less important.

Niman is trying to make a case for recombination versus reassortment as the primary means by which the virus aquires changes. This places him outside the virological mainstream (though it doesn't necessarily mean he's wrong). As a whole, the serology does not so far support the claim of widespread subclinical cases (though, as Niman and others constantly point out, more studies are badly needed).

The size of the latest Indonesian cluster is troubling.

 

[Skeptic Ginger]

But that 208 cases is only the most severe ones, that required hospitalisation. Hardly ever any mention of how many 'neighbors' had mild cases. Just an occassional hint of 'testing for antibodies' in general populations, so we really don't know any ratios/percentages.

Actually, a few surveys, (thought not nearly enough to be certain), have been done on the blood of people who should be exposed like workers in the hen houses and not much antibody has been found. It may be that in the countries better at reporting cases we are indeed seeing most of them.

OTOH, in most African countries there are no reported human cases. That seems like the cases are being missed to many of us following the situation.

 

[Skeptic Ginger]

What we know darn little about is how the virus, in its present form, spreads from birds to humans.

I wouldn't say that either. Chickens are excreting the virus in feces. The virus replicates in most of the implicated birds' tissues. People have become infected slaughtering birds, drinking raw duck blood, entering chicken coops or otherwise being in close contact with ill birds. Some children were playing with dead birds, in other cases chickens were treated as pets by some of the children who got infected.

In later cases in Egypt and Iraq less details were reported.

Niman is trying to make a case for recombination versus reassortment as the primary means by which the virus aquires changes. This places him outside the virological mainstream (though it doesn't necessarily mean he's wrong). As a whole, the serology does not so far support the claim of widespread subclinical cases (though, as Niman and others constantly point out, more studies are badly needed).

What do you mean by recombination? That sounds the same as reassortment. Did you mean to say by mutation vs reassortment?

I'll have to look up the researcher you are referring to. But the H1N1 virus that caused the 1918 pandemic was determined not to be a reassortment. I'm sure that's what Niman is going by.

The size of the latest Indonesian cluster is troubling.

Wait and see. It isn't the first cluster and other clusters did not amount to much. The real worry is going to be when there is more than just a cluster. It's going to be the 30 or so cases in Nigeria that occurred under the radar. If the family in Indonesia have a transmissable strain, it's likely to have been contained.

 

[Bowser]

What do you mean by recombination? That sounds the same as reassortment. Did you mean to say by mutation vs reassortment?

Recombination, reassortment and mutation are all different. The virus exists as eight separate RNA strands. Reassortment usually means a mix and match of eight unsegmented strands. Recombination is snips of the strands being traded between strands. (There are better descriptions elsewhere.) Niman pushes the recombination theory of influenza evolution.

Many individual cases (your Nigeria example) may not mean anything more than many individual b2h. A large cluster is more likely to point to h2h2h2h.

 

[Dymanic]

I wouldn't say that either. Chickens are excreting the virus in feces. The virus replicates in most of the implicated birds' tissues. People have become infected slaughtering birds, drinking raw duck blood, entering chicken coops or otherwise being in close contact with ill birds. Some children were playing with dead birds, in other cases chickens were treated as pets by some of the children who got infected.

One of the easiest ways to contract influenza is to touch something an infected person just touched after having wiped their nose or whatever. Then, you touch your own nose, or rub your eyes, like you do hundreds of times a day, without thinking about it or even realizing you're doing it. The virus is then given access to some of the cells having sialic acid structures of the type the virus's hemagglutinin protein can bind to. Inhaling small airborne particles is another way that the virus can enter the upper respiratory tract.

But in its current form, the virus doesn't easily bind to the receptors found in the human upper respiratory tract, so how it has managed to infect humans remains an open question. Of all the people who have frequent contact with birds, only a vanishingly small number have become infected with H5N1. Did they become infected because they recieved an unusually high exposure? Because of a genetic predisposition -- say, a different ratio of ciliated versus non-ciliated cells? Because of some rare behavior that enabled the virus to reach the deep lung, where the cells with the receptors it likes are found? Because the virus they were exposed to represented a mutant strain with better affinities for human receptors? We just don't know.