Members of the ACSH staff this week attended a continuing education seminar for health professionals on the subject of preparedness for biological, chemical, and nuclear emergencies. The seminar was based on an excellent publication prepared for the Medical Society of the State of New York, which reviewed salient facts about a full spectrum of potential terrorism agents including smallpox, anthrax, ricin, plague, and sarin.
We were struck by the fact that even the lecturers began by noting that three years ago, they knew basically nothing about the biological and chemical threats of terrorism that they were briefing us on that afternoon. They recalled vague references to anthrax, ricin, and other such topics during medical school. But who would have predicted these doctors would need detailed information on this subject in later years? These lecturers brought themselves up to speed on the issues and were now communicating what they had learned to colleagues.
The physicians and health professionals present listened intently as they were instructed how to make diagnoses and separate out, for example, simple cases of the "flu" from the potentially deadly effects of Bacillus anthracis. And well they should listen up, as these New York physicians could be the first to detect signs that a biological or chemical attack had been launched in our city.
As the seminar covered the full spectrum of potential agents of terror, we were again impressed that one particular agent stood out as having the most potential to wreck havoc upon our health: anthrax.
Anthrax falls in "category A" of the CDC's biological agent ratings because it
--can be easily disseminated or transmitted person to person (anthrax meets the former but not the latter criteria)
--can result in high mortality rates and has the potential for major public-health impact
--might cause public panic and social disruption
--and would require special action for public-health preparedness.
Anthrax is, in many ways, the ideal biological weapon.
It can be concealed easily as only minute amount are necessary to kill large numbers of people. It has high potency, is accessible in laboratories around the country, and it is "sturdy" spores can be stored for decades and are not easily destroyed by high temperatures or disinfectants.
Perhaps most important, anthrax as a biological tool to kill people is not a mere hypothetical risk. The October 2001 bioterrorism attacks via the U.S. mail caused twenty-two cases of anthrax , half of which were inhalational, half cutaneous. Five of the inhalational cases were fatal.
The 2001 attacks were "successful" in that people got sick and some died, but a much more efficient distribution of anthrax via aerosol delivery would generate an invisible cloud of small particles or droplets that can remain in suspension for long periods, causing a serious inhalation risk. If efficiently deployed, a biological agent such as anthrax could be effective in both small and large populations. The World Health Organization in 1970 estimated that 50kg of anthrax released upwind of a city of 5 million people could cause 250,000 causalities and 100,000 deaths. Twice that amount released in Washington, D.C. is estimated by the U.S. Congressional Office of Technology Assessment to cause between 130,000 and 3 million deaths.
The hazard posed by anthrax is determined by its form. Anthrax spores normally tend to clump together, which prevents deep lung penetration. Weaponizing anthrax may involve refining the particles to enable deep lung penetration. A true nightmare scenario would involve genetically altering the anthrax spores so they are antibiotic-resistant.
But, you might argue, in a "normal" anthrax attack, we could quickly intervene and treat people with Cipro or another antibiotics and save lives.
Maybe.
Treatment intervention would only be successful if we knew that the exposure occurred and people could be treated right away. In the worst-case scenario, if anthrax were dispersed in an open or closed area in a subversive manner and went undetected the first sign of an anthrax attack would be large numbers of patients presenting to the emergency room in severe respiratory distress at which point, Cipro is basically useless.
What is most worrisome about anthrax is, as mentioned below, the tiny amount of exposure needed to kill a person. Recall that the elderly woman in Connecticut and the New York City woman who died in the fall of 1991 from inhalational anthrax were never directly connected to a source of anthrax. It is surmised that a piece of mail from a contaminated mail machine came into the Connecticut woman's home and infected her. No one knows how the New York woman was infected.
The bottom line: the threat of an anthrax attack is very real and very worrisome. How can you protect yourself?
--Having a supply of Cipro on hand might be a reasonable attempt to protect yourself, but again, you would have to have known that you were exposed to have the antibiotic help you.
--Keeping alert as to suspicious aerosol releases and reporting any incident would be logical. But as the seminar's lecturers reminded us the other night, in the New York area, as we try to kill the mosquitoes that transmit West Nile virus, we see aerosol sprayings all the time.
--Encouraging our public health officials to give a higher priority to the development of a safe, effective vaccine against anthrax is another viable option, one which we ought now to consider very seriously.
An anthrax vaccine was first licensed in 1970. In 1997, all U.S. military personnel were required to receive the vaccine. With FDA approval, more than 2 million doses of the vaccine were given to over 500,000 service men and women. The vaccine has proven to be safe and effective. It is given in six doses, although after two or three doses some protection is evident. There is also a new DNA-based anthrax vaccine on the horizon, known as recombinant protective antigen (rPA), that is about to undergo the first phase of human clinical testing.
The problem for now is that current vaccine supplies are very limited and only modest new supplies are being produced. There are future plans to add 75 million doses of the next-generation anthrax vaccine, not yet available, to the Strategic National Stockpile enough for only 25 million Americans as part of Project BioShield. Presumably this would be enough to mount a defense in a large-scale attack, such as terrorists spraying anthrax over a city by plane. But again, we would have to be aware that such an attack has occurred before such a defense could be employed.
Why is there no big push to make anthrax supplies available to all American consumers who wish to protect themselves? Most likely because Americans have forgotten October 2001's anthrax attacks which remain unsolved and thus assume that (a) it could never affect them and (b) if it did, their motto will be "In Cipro We Trust."
Maybe now would be a good time to reassess the stark dangers posed by anthrax in the hands of terrorists and come up with a reality-based plan to protect ourselves by making safe, effective vaccines available for all of us.
Elizabeth Whelan, Sc.D., M.P.H., is president of the American Council on Science and Health. See ACSH's guides to anthrax and terrorism.
