jueves, abril 30, 2009

What You Need to Know About Swine Flu

What You Need to Know About Swine Flu
Prof. Robert Bragg, Dept. of Microbial,
Biochemical and Food Biotech at Uni. of Free State, SA
Nicolas van der Leek (Nick)

This is a transcript of a recent interview with Professor Robert Bragg,from the Department of Microbial, Biochemical and Food Biotechnology at the University of the Free State, South Africa.

Would you say we, as in "the world," lack urgency in response to what we currently know?

No. The veterinary services have a management team looking into avian influenza.


Yes. In South Africa there was the ostrich outbreak recently, although it was a slightly different virus.


Yes. South Africa remains one of the few countries that has successfully eradicated an avian influenza outbreak through isolation and the use of suitable disinfectants.

So we have a good capability?

Yes, we have a good capability and people are monitoring migratory birds that are coming in.

Was SARS (Severe Acute Respiratory Syndrome) an aberration?

SARS was also a virus that went from animals to humans. But it's a different virus. It's a corona virus.

But did it shock and surprise?


So it was an aberration?

Yes, it was an unknown virus. You have certain viruses that cross the species barrier. And when they do, they cause problems. Because they've crossed that species barrier they've lost their specificity for specific cells, and that means that they become more virulent.

Flu is at its most infectious when you're asymptomatic. So if you installed airport scanners, would they work?

They worked for SARS as people were only infectious once they started showing clinical signs, eg. high temperature. But they wouldn't work with bird flu. There's basically diddly squat we can do about it.

My information is not scientific. For example, at Hong Kong airport (on Nov. 11, 2005) they were saying to people "you need to wash your hands if you've handled live poultry."

The big scare at the moment is the virus has been able to spread from chickens to humans. Any good hygiene practices, such as washing and disinfecting of hands when working with poultry, is a good idea. The virus hasn't developed human to human transmission.

Is that certain?

No. It's not certain but it's likely. If that happens we're going to have a major pandemic.

I know this isn't very scientific but I watched a documentary with footage of Vietnam where they felt that there had been a human to human (transmission) between a family. That was an isolated thing, but if you look at the trends based on the news?

The main reason the people are culling the birds when there's an outbreak, is to limit the bird to human transmission. The more bird to human transmissions you get the better the chance (the virus will) develop human to human transmission.

The latest information from China indicates that their virus has mutated, but has still not developed human to human transmission. And once it's developed human to human transmission then it's going to grow. And the problem with this virus is it's a nasty virus.

What concerns me, and I've been following this for weeks, maybe months, is that the news reports are increasing. In 1918 (the media) often denied it, even though it was happening.

Under certain circumstances you can understand it. But on a personal level people can limit certain kinds of behaviour like overseas travel and so on. What concerns me is: I lived in the Far East for 4 years, so I'm aware of how dirty and crowded it is there.

And now it's winter there. And today another woman died in China. Even though it's one case. And I still have a mild case of a flu I picked up in South Korea. So you just need one case of someone with the flu getting bird flu, you know?

If you start comparing the 1918 outbreak, and you start delving into what happened, and you start looking at what's happening now, it starts getting a bit scary. We've just got to hope that it doesn't develop human to human transmission.

I feel like that no one's thinking about it really.

No. Ordinary people are not thinking about it.

But shouldn't they be?

There's not really much that can be done about it. If this virus develops, if it gets to the human to human stage, we can pretty much do what we could do in 1918 and that is nothing.

Couldn't you start taking multivitamins?

It's not really going to help. It may boost the immune system, which will help, but basically it is the person's immune system which will have to combat the virus. It's best that (people) don't really realise the full extent of the concern that's going around.

So if you knew something you wouldn't tell your wife?


You wouldn't?

(muffled)...uh...The problem is if this virus develops human to human transmission the world's going to know about it anyway.

What do you envisage?

I think the probability that it's going to develop human to human transmission is high.

Yes. And what sort of timeframe?

It's difficult to say. If you look at stuff on the Internet and you're listening to what's on the radio...the disaster management (operations) in Australia and the States ? they're not talking about 'if' it happens, they're talking about 'when' it happens.

I'm aware of that. Branson bought 10,000 vaccines for his airline staff, and he did it now, believing they're on the frontlines of the disease.

That's the other problem. The virus hasn't developed human to human transmission. When the virus develops human to human transmission it might change. So the vaccines that you're using now are not necessarily going to have an effect.

Like Tamilflu?

That's a medication. The vaccines might not work. The virus is changing. There's a good probability the vaccines will work, but the vaccines are produced in eggs and it has to be in special eggs, so called SPF eggs which stands for "Specific Pathogen Free" eggs.

Chicken eggs?

Yes, specific pathogen free eggs. But the problem is that as this is a poultry virus and is highly virulent for poultry, it is difficult to make a vaccine in eggs, because the embryos die before there is a high concentration of virus which is needed for vaccine production, so it's very difficult making the vaccine.

How quickly will it be picked up if there is a case of human to human transmission?

I think the monitoring is in place. The monitoring of migratory birds all over the world (and) coming into South Africa (is there). The monitoring of poultry industries all over the world is very geared towards avian influenza at the moment.

You were saying it's a 'nasty' virus. Are we seeing it becoming more lethal?

In poultry it's deadly. It kills chickens within a few days. If it gets into a poultry house of 30,000 birds, three days later they're dead. When people have got the virus from birds you're looking at a 67 percent mortality rate. The 1918 epidemic was between 3-5 percent.

Where do you think Ground Zero is?

You mean where will it break out? It's in the East. Indonesia, Thailand, Vietnam, China. Basically where you have the rural environment. People with pigs and chickens living in the same environment.

Is bird flu spreading to pigs?

At this stage I'm not sure it's got into pigs. The 1918 epidemic did have a cycling effect, and quite often the virus does go into pigs. Normally the pig is the mixing vessel. If a pig picks up an avian influenza virus from birds, a human influenza virus from humans and has its own influenza virus, the viruses re-associate in the pig and what comes out of the pig is often a problem.

For people?

For people. This one has skipped out the pig. If it goes through the pig it might increase the probability that there could be problems in terms of human to human transmission.

This concerns me. A healthy economic apparatus. With fast food chains we have an incredible demand for food. We have mass production of chickens and other animals. Does this sort of unnatural production of livestock, of poultry, do you think that is the source (of H5N1)?

No, it wouldn't be the source but whenever you start putting any animal into mass production, your probabilities of diseases increase. But you wouldn't get a spontaneous generous of (this) virus. But you know if you have a small fire it's easy to put out. You can blow a match out but you can't blow a forest fire out.

So is the source of H5N1 and all these HN variants; is it just a natural fluctuation?

Yes. The normal influenza that we get is different combinations, but they don't have the increased virulence. So if you have the flu this year, you're not going to get the same strain next year. They'll be a different combination of H and N. This particular combination that we're getting now is a problem because it makes it virulent.

Okay so we have a natural source, but the world has become so unnatural. We've got six billion people, we've got so many people with AIDS, so aren't the implications quite severe? Are the indications quite serious?

If this virus develops human to human transmission it's going to be really serious. Putting these things into a magazine, you've got to be careful you don't create mass panic.

That's not what I do want to do, because it's South Africa, and because it's my home...

Basically once you get to human to human transmission, there's not a lot that can be done.

What about vaccines?

If the virus mutates the vaccines are going to be useless. The problem is also you can't just all of a sudden produce a whole lot of vaccines. For two reasons: one, the vaccine manufacturers don't know what the virus is going to look like.

So they wouldn't want to produce tons and tons of vaccines and then the virus changes. The problem is you also just can't get enough SPF eggs to produce the vaccine you need. Even if they know what the virus is there's a limit to how many doses of vaccine can be made.

That's a difficult thing to solve, but on a more practical level, what can you do? As far as I know, Australia has already simulated it. Simulated bird flu breaking out.

With SARS, when I was in the Philippines a year ago, they had devices that monitored body temperature installed at the airports. But if you look at the 1918 virus, that virus got around the world three times in eight months when there weren't planes.

I think they went with ships.

Now with international air travel, if it breaks out, if you get serious human to human transmission in, say, Cambodia, in 96 hours it's around the world.

What about...here we are in Bloemfontein, on the Free State campus. We've got the hospital right next door. I mean some kind of emergency plan so that there's not chaos or a situation where we need 1,000 beds.

I don't know what the different countries' disaster management plans are.

That's my concern for this country.

There is a well established disaster management system for this country.

What do you mean?

Managing and controlling situations and disasters. If there's a fire or a flood for example.

Do you think that's adequate?

It probably would be adequate. (Pause) If it develops human to human transmission ? if it breaks ? it's going to be a worldwide disaster on an unprecedented scale.

It's hard to convey that without spreading panic. I see that when it happens, everyone will have to stay home. You'll see an immediate worldwide paralysis.

Yes. They're estimating in Australia, if this virus breaks, it's going to take businesses three years to return to normal.

So people are saying it's inevitable. So what do you think? Next year?

You can't put a timeframe to it.

Is there not a trend?

If you look at the epidemiology the influenza pandemics go in cycles. And when we're pretty much in the stage where it's expected.

You know if you drive on a road, then you see a sign that says, "High Accident Rate Next 7km". So when did our sign start?

They started getting worried, they started feeling that the cycle was coming, 'round 4 to 5 years ago. And that's round about the same time this virus started popping up. Popping up all over the place. It pops up in Thailand, and then they get it under control. Then it pops up in Indonesia, then it pops up in Thailand again. So it's like a boiling pot. You squash it there and it comes up there. And all the time it's the same or a very similar virus.

What is the cycle?

I don't know offhand what the cycle is. But you know the 1918 was the most serious. They reckon over 50 million died in 1918. That was a serious outbreak. It goes in cycles, and timewise we're at a point where it's expected. But it's a biological entity, so you can't apply mathematical formulas to it.

I know migratory birds congregate at Langebaan. What are vulnerable areas in South Africa?

We have a swift bird nest at our house. It's just come back, you know. I don't think the virus really got into Russia by the time they left (for Africa).

Is the primary agent the duck?

Yes, the duck carries the virus without severe clinical signs. The duck doesn't die.

That's interesting. So maybe it comes from a water source somewhere. Should we try to make the vaccine available in South Africa?

There is a vaccine available for poultry. There were some mutterances that the government was going to allow the vaccine in. We're an avian influenza free country, apart from the case of the ostriches in 2003. The country has recently regained its AI free status. As a routine the poultry in this country are not vaccinated. And there's not a ready supply of vaccines.

When you say available, you mean internationally?


So wouldn't that be something we should call for: a national stockpile.

It's a bit of a catch 22, the government has successfully controlled disease outbreaks in the ostriches (and others, like foot and mouth virus), and they've got a well established system for localising it and preventing it from getting out. So do you go for the stamping out policy or do you vaccinate? The problem is if you vaccinate you lose your monitoring scheme. You can't monitor if the birds are vaccinated.

I know in China they've found that some of the vaccines used were counterfeit. Okay this might seem like a stupid question: What role does AIDS play in H5N1 and is there any chance of a recombination between HIV and H5N1?

They're totally different viruses. If the pandemic breaks, the only thing that is going to save a person is your immunity. And obviously if a person has HIV their immune system is not up to standard.

Who in South Africa is responsible for dealing with this issue?

From the poultry point of view, the veterinary services have got a committee.

The South African Poultry Association and Veterinary Services are looking at (H5N1) very seriously. There's a lot of expertise in the country on the avian side of the disease.

I don't know what's happening on the medical side.

Last question, what are your latest thoughts on this?

You know, I keep watching the news, and every now and then (I) get on the Internet to see what's happening. Basically my thoughts are: I'm just hoping and praying it doesn't develop human to human transmission. Because if it does ...

When it does.

I'd still like to say 'if' it does...If it develops into human to human transmission, we're going to have a big problem. It's going to be by far the most serious disease outbreak that the world has ever seen. The 1918 (virus) remains the pathogen that's killed the most people on Earth.

Something like 152 people have died so far, with 2,000 infected. But that can change in an hour.

At the moment, as you say, 152 people have died, it may not seem like news headlines. But if you think of the number of times it's been reported, you can start getting some idea of the concern behind it.

For more information: www.nickvanderleek.com

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