JANA WENDT: Professor Spratt, thank you very much for joining us.

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What do we know about the strain of anthrax involved in these US incidents?

PROFESSOR BRIAN SPRATT, EPIDEMIOLOGIST: Well, the reports we have so far is that it`s a strain called the aim strain, which is a fairly well-known strain of anthrax. Most people who work on infectious diseases have a sort of favourite strain of a particular pathogen. One that is used by many of the laboratories doing research on it, so there`s some sort of standardisation between laboratories. So I think the aim strain is a strain like that. It`s a strain that most laboratories working on anthrax would have and, for example, the complete genetic blueprints of bacillus anthracis – the anthrax bacterium is being obtained and the strain that is being used is this aim strain.

JANA WENDT: Does this genetic blueprint give us any clues about how this anthrax has been made?

PROFESSOR BRIAN SPRATT: I don`t think the actual strain tells you very much, except that it has been reported that this particular aim strain is not one of the strains which is being weaponised. If it had been a strain which had been weaponised, then it would point fingers in particular directions. Because the strain is this aim strain, which is fairly widely distributed amongst the labs that work with anthrax, I don`t think it tells us very much about where it comes from or who is perpetrating these crimes.

JANA WENDT: You used the expression `weaponised` and it is certainly being used a lot these days. How do you define weaponised?

PROFESSOR BRIAN SPRATT: I think you have to look at how a single small terrorist group or individual would try and produce anthrax. They would grow the bacteria up, they would produce spores and they would concentrate those spores and they would dry those spores down. The problem with doing that is that the spores would tend to be in rather large clumps. They would be in particles which would be too large to get down into the lungs, and they would therefore deposit in the upper respiratory tract and then they would be swallowed. So if you want to make a weapon out of anthrax, you need to take the dried spores and you need to grind it down and modify it so that the spores are in very small particles, which can get right down into the lungs and can cause infection. So that`s what we mean by weaponising.

JANA WENDT: OK, so you are saying that this anthrax strain that has been detected in the United States, has not in fact been weaponised?

PROFESSOR BRIAN SPRATT: That is what I heard. I don`t know if that`s absolutely certain. But I have heard it said that this particular strain was not one of the strains that they found being weaponised in either the Iraqi or the ex-Soviet Union bio-weapons program.

JANA WENDT: So can we conclude from that then that the Soviet Union, the former Soviet Union, and Iraq are perhaps not likely sources of this anthrax?

PROFESSOR BRIAN SPRATT: Well, I really don`t think we know. I mean, I think at the moment because it`s the aim strain it could have come from a whole number of sources, including al-Qa`ida. But also it could come from people inside America with a particular grudge against society. So I think really we don`t know and the signals we are getting are very mixed and, interestingly, at least in the last few days, the finger has not been pointed at Iraq, Afghanistan or anywhere outside America. So we`re really not sure at the moment.

JANA WENDT: Professor, are you saying in fact that science isn`t going to unlock the door to this mystery?

PROFESSOR BRIAN SPRATT: I think it`s very difficult because if it`s the aim strain it could have come from a number of different sources. It`s just possible that there is a certain amount of micro-variation that geneticists or microbiologists could possibly use to tie the particular strain down to one particular laboratory or one particular repository of bacterial strains. But that is fairly unlikely with this particular organism, so I think it would be difficult. Of course what can be done is that all of the laboratories which hold stocks of these strains can look through their records to try and find out who the strain was sent to. That`s probably the best bet that we have at the moment.

JANA WENDT: Professor, let`s look at the other side of the coin. How difficult or easy would it be for a backyard operator to produce anthrax?

PROFESSOR BRIAN SPRATT: Well, I think first of all of course you have to get hold of the strain and there are some difficulties there. Having got hold of the strain, you then need to grow it up in a liquid sort of broth. You then have to concentrate the bacteria and dry them down. So I think you have to protect yourself, you need some basic bits of equipment, but it`s probably going to be a matter of getting together maybe US$20,000 worth of equipment – and it`s fairly standard laboratory equipment. It shouldn`t be too difficult to get hold of. I don`t think it is too difficult if you have some basic knowledge of microbiology. You know how to protect yourself. You have a safety cabinet of some sort. You have a centrifuge which gives you protection. So it`s not that difficult if you can get hold of the strain.

JANA WENDT: Professor, we are seeing postal workers contracting the inhaled form of anthrax and it seems that those people who are actually opening envelopes that contain anthrax are only contracting the skin form of anthrax. Do you have any reason why that may be the case?

PROFESSOR BRIAN SPRATT: No, not really. I think we don`t know the reason for that at the moment. You would have thought that the person who actually opened the letter and the anthrax then blew around would get a reasonably high dose of spores, and would be likely to get inhalation anthrax, whereas postal workers with sealed envelopes you would have thought it would be less. But we don`t really know what happened, we don`t know how many letters there were, if any of them burst open. So I think at the moment we just don`t know the answer to that.

JANA WENDT: We know from an accidental release of anthrax in the Soviet Union in 1979 that cases of anthrax took quite a long time to develop, some weeks in some cases. Do you expect this pattern to be repeated now in the United States?

PROFESSOR BRIAN SPRATT: Yes. Of course, it all depends on when the anthrax letters were sent. Some of them were allegedly sent on September 11th or around about that time. We appear to be still seeing cases from that. That is consistent with what we know about the incubation period. The time from acquiring the organism to getting the disease, which is rather variable and it can go out for several weeks. So we may even be looking for letters that were sent on 11th September – we may still see some more cases.

JANA WENDT: OK, Professor, we will have to leave it there. Thank you very much for your time tonight.

Professor Brian Spratt Interview