What do you think? Leave a respectful comment.

The video for this story is not available, but you can still read the transcript below.
No image

Tracking Anthrax

Ray Suarez examines the medical implications of anthrax with Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Read the Full Transcript

  • RAY SUAREZ:

    Joining me for that is Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health. Dr. Fauci, a lot of attention is being paid to the people who contracted, not contracted, who came in contact with anthrax at the Hart Senate Office Building. Now it's been very carefully worded that they've tested positive for exposure, but are not ill. Help us understand what that means.

  • DR. ANTHONY FAUCI:

    Sure. Exposure means that you have the identification of a spore on a part of the body — usually in the nasal passage, when you swab — or, for example, if they were on a skin where they were able to swab it. So they've been exposed. They don't have the disease and they're not infected. Infected means when that spore makes the transition from a relatively inert particle, what we call germinating, that it becomes the full-blown bacteria. Once it does that, it actually infects the individual. It could be inhalation infection, which is very serious, or the less serious form, which is the cutaneous form. That's what infection means, whereas exposure alone doesn't necessarily mean that you've gone onto that next step of actually being infected.

  • RAY SUAREZ:

    Could that number 31 in a way almost overstate what we're dealing with here? Would many of those people never have even known that they were exposed in this way had we not swabbed them?

  • DR. ANTHONY FAUCI:

    That is conceivable, but you must err on the side of great caution, because we know that these spores can actually germinate several days, weeks or even more beyond the point that they actually get in the person, on the person's skin or in the nose. So that's the reason why you want to treat individuals who have been exposed, and in fact you don't want to take a chance, anyone who even conceivably could have been in that arena where the exposure occurred, because often we don't know how often, you could swab someone and they would test negative when actually there might be a spore here or a spore there, because they're very tiny and it depends on what the concentration of the exposure is.

  • RAY SUAREZ:

    What about the common wisdom that you have to come in contact with an awful lot of spores to actually get sick?

  • DR. ANTHONY FAUCI:

    Well, that's not necessarily so, except under the circumstance when you talk about the number of spores that would be required to give you inhalation anthrax. They usually say it has to be around ten thousand, somewhere between eight and fifteen thousand spores. That's the inoculum that would be required for those spores to get into the position to do what I just mentioned, to ultimately germinate, become the full blown bacteria and then do their nasty things in the body, which is secrete toxins, infect cells and then widely disseminate.

  • RAY SUAREZ:

    A lot of attention is being paid to the form that these spores took. Maybe we can understand a little better the two tracks that these questions are on. First, virulence of strain: Are there different genetic lines, some that would make you more sick more readily and others that would –

  • DR. ANTHONY FAUCI:

    Yes, there are certainly that. For example, the strain that was attempted to be used in a terrorist fashion in Japan a few years ago by the Japanese terrorist group happened to be a very relatively benign and not virulent strain. But when people are talking about the capability of the microbe, it's the grade of the spore and how they were refined and put in a way that's much more likely to disseminate in an aerosolized or airborne way, versus one that's crudely made and just might clump to the ground and be much less dangerous. That's the danger — is the potential for the spread of the spores. That really dictates the potential and the capability of either getting in the lung of a person, or disseminated widely like sneaking into the ventilation system, the way it seems to be the case in the Daschle building one.

  • RAY SUAREZ:

    So spores from the same family, the same genetic line, depending on how they're milled, on the form that they take always a powder, could be more or less dangerous?

  • DR. ANTHONY FAUCI:

    Right. That's the point, if it's not well prepared, it could be a relatively not very dangerous component of what's trying to be done, namely bio terror. If it's put in a form where it has the capability of this dissemination or just the right size to get through into the nasal passages, that one to ten micron size, those are the ones that are dangerous because they can get into the respiratory tract, whereas, if you get one that's crudely made, starts to clump, different sizes, it may not do anything with regards to getting into the nasal passages.

  • RAY SUAREZ:

    We had 31 exposures on two floors in a corner of one building. Does that signal to you that this was well made stuff, that the people who may it knew what they were doing?

  • DR. ANTHONY FAUCI:

    From the phenomenological standpoint, just observing to me, having not seen the data on the analysis, would suggest to me that in fact that was of a grade that had the potential to disseminate in an aerosolized way much better than perhaps a more crude preparation.

  • RAY SUAREZ:

    It was mentioned in an earlier report that people are doing 60-day regimes of antibiotics. That's unusually long, isn't it?

  • DR. ANTHONY FAUCI:

    Well, that is long, but that's based on an animal model of infecting animals and treating them for 30 days and then observing that some animals even after you stop treating for 30 days perhaps even up to 20 or more days beyond the termination of treatment, they were still able to demonstrate spores in those individuals. So because of that, an empiric decision was made that it should be 60 days of the antibiotic, and it was purely on the basis of trying to err on the side of safety to make sure you get those, all of those spores eliminated rather than stopping perhaps prematurely with 30 days.

  • RAY SUAREZ:

    But, I guess what I'm getting at is, this isn't something you would want to embark on lightly or frivolously. People are stocking you on antibiotics around the country.

  • DR. ANTHONY FAUCI:

    That gets to the point that has been discussed a considerable amount — is the value or lack thereof of having individuals be taking antibiotics in a relatively empiric way, namely without necessarily having the kinds of exposure that we've been seeing demonstrated, identified and appropriately treated. That's the difficulty with inappropriate antibiotic administration. Not only could it be toxic, particularly if you're giving it for a 60-day period, but then you have all the other problems of perhaps even selecting for resistance of microbes that are not anthrax, something else that you might ultimately need those class of antibiotics for. So there are a number of reasons to be, (a), careful if there indeed is an exposure and err on the side of caution for treating. But if there's no indication whatsoever that you were physically in a place where there was an exposure, that that person who maybe looks at television or reads in the newspaper and said oh my God I'm going to start throwing down some antibiotics, that's inappropriate and that's where you get into trouble.

  • RAY SUAREZ:

    Dr. Fauci, thanks a lot.

The Latest