Ron Atlas: Sourcing bioterrorism
Dr. Ron Atlas is the co-chair of the American Society for Microbiology's task force on biological weapons. He is a professor of biology at the University of Louisville and the dean of the graduate school. Dr. Atlas has previously testified on the issue of bioterrorism before the United States Congress.
CNN: Welcome to CNN.com Newsroom Dr. Ron Atlas. Thank you for being with us today.
RON ATLAS: I'm Ron Atlas at the University of Louisville, and I'm happy to answer your questions.
CNN: New cases of anthrax exposure and infection continue to be reported. Do these new cases provide more evidence that helps authorities solve or find patterns to these crimes?
ATLAS: I'm sure that the new cases will help us find a pattern, although what we seem to be seeing, at least with the postal workers, is the route that the mail traveled. The question for some of us is how the spores are getting out of the envelopes and airborne along the route of travel. It may turn out within the postal system the way air is blown across, some of the air that is causing some additional problems, by getting spores airborne. That may help explain why some of the letters received by the media in New York are resulting in the skin form of anthrax, where in other cases we're seeing the more serious form of anthrax, the inhalation type.
CHAT PARTICIPANT: If spores are getting out of envelopes, can they hop a ride on other envelopes?
ATLAS: Once the spores get out of an envelope, they can spread and contaminate other surfaces. Usually, though, they settle and also become less concentrated. That greatly lowers risk of contracting anthrax, since it requires thousands of spores to cause an infection.
CHAT PARTICIPANT: Dr Atlas, is it possible for someone who has contracted the skin anthrax to later display symptoms of the inhalation anthrax?
ATLAS: The difference between skin anthrax and inhalation anthrax is how the spores enter the body. It is conceivable that someone would have some spores enter through a wound, causing skin anthrax, and also have inhaled spores, causing inhalation anthrax. The drug we use to treat both would be the same.
CHAT PARTICIPANT: Dr. Atlas, isn't it easy to make bacteria resistant to antibiotics?
ATLAS: Certainly, genetic engineering allows us to make bacteria resistant to antibiotics. That's a bit more difficult for a bacterium that causes anthrax, but a really technical person could have done that. That may tell us something about who is behind the current attacks. It may also be that anthrax is a sufficient threat, particularly to cause terror, without making it more draconian by introducing antibiotic resistance.
CHAT PARTICIPANT: My husband was in Desert Storm and was immunized for anthrax. Is it still effective? By the way...he is now a mailman.
ATLAS: I don't know how effective the anthrax vaccine is in terms of longevity. Many vaccines are effective for about ten years, at which time we often use booster vaccines to renew immunity.
CNN: What will authorities need to find in order to confirm or rule out Iraq's involvement?
ATLAS: There are several things that authorities would be looking at for determining whether a foreign power is responsible for these attacks. One will be the nature of the strain, which has been genetically fingerprinted. We then need to rely upon intelligence information to indicate whether Iraq had that particular strain. We may be able to conclude that they did not. Another thing that we look for is the uniformity of particle size, and the concentration of spores. If a major power is behind these attacks, we would expect very high concentrations of spores and a great uniformity of the particle size of the powder, specifically in the range that is likely to cause the most infections. If we don't see that, the evidence would be pointing away from Iraq.
CHAT PARTICIPANT: How would uniformity of spore size determine a location of manufacture?
ATLAS: The uniformity of spore size, or rather of the powder, not the individual spores, would indicate how sophisticated this operation was. If the powder is very uniform, and the spore concentration very high, it would indicate the sort of sophistication that existed in the former Soviet Union, or in Iraq's biological weapons program. That would indicate a level of expertise at least, which would narrow the field of potential perpetrators.
CHAT PARTICIPANT: What are the chances that Russia sold this anthrax to Iraq years ago? How then would you determine who is sending it?
ATLAS: There have been frequent concerns that individuals from the former Soviet Union provided expertise to Iraq. We can't eliminate that possibility, but it is equally possible that such experts have provided expertise within the United States. At this point, we are unable to determine who is behind the wave of anthrax attacks.
CHAT PARTICIPANT: How fast can anthrax be produced? How sustainable is this attack? ATLAS: Anthrax is a bacterium that can be grown quite rapidly. One could produce limited new supplies on a daily basis. So far, we seem to be seeing very limited amounts in envelopes, suggesting that this can be sustained for some period, until the perpetrators are identified.
CHAT PARTICIPANT: We typically think of anthrax spores as white. Does it need to be on a white powder, or can it be invisible?
ATLAS: The spores moving through the air would be invisible. They could be on a powder of any color. And in fact, the reports suggest that a number of the powders have not been white, but brownish in color.
CHAT PARTICIPANT: Does anthrax have a life time? ATLAS: Anthrax spores can survive essentially indefinitely, but contracting infections requires a high concentration. Therefore, if the spores are dispersed, the risk of disease becomes nil, even if the spores survive in nature.
CHAT PARTICIPANT: What is the potential threat of smallpox?
ATLAS: Smallpox has potentially a greater threat than anthrax because it is a communicable disease, meaning that it can spread from one person to another. It has a fatality rate of about 30 percent. The good news is that smallpox virus does not occur in nature, and therefore it is far less likely that anyone can gain access to this virus. In contrast, anthrax occurs all around the world, and anyone could have gained access to strains of this bacterium.
CNN: Would you advocate a renewed effort to vaccinate Americans against smallpox?
ATLAS: The question of renewing smallpox vaccinations is complicated. The vaccine is not without risks. If we introduce smallpox vaccination, some people will become ill and some will die from the vaccine. To undertake such a program requires that we really know that someone is about to attack us with smallpox, or that an attack has occurred. Short of that, the risk from the vaccine probably exceeds the cost we're willing to pay.
CHAT PARTICIPANT: If something like a cropdusting plane were to be used to spray smallpox over small areas of the population, would the CDC be able to quickly determine that what was sprayed was hazardous, and would they immediately inform the public? ATLAS: I think the CDC has been very up front with the public, and if smallpox was introduced by any means, would respond immediately by trying to vaccinate individuals in the region that might have been exposed. The current health plan is to use the available doses of smallpox vaccine to surround any regions where individuals may have been exposed.
CNN: Do you have any final comments for us today?
ATLAS: I think the American public should recognize that the public health system has been able to respond to the current threat. There are adequate antibiotics, and while a number of individuals have tragically been afflicted by this horrific attack, public health response has been able to protect many individuals who may have been exposed. I think the rest of us should take heart in knowing that we are on top of the situation, and providing adequate public health response. CNN: From: Thank you for joining our discussion today, Ron Atlas. ATLAS: Thank you very much. I look forward to at some point speaking to you again. Dr. Atlas joined CNN.com via telephone from Louisville, KY. CNN provided a typist. This is an edited transcript of the interview, which took place on Monday, October 22, 2001.