Fears of a biological terrorist assault have gripped the United States and other parts of the world after more cases of anthrax-tainted mailings were confirmed in recent days. RFE/RL correspondent Kathleen Knox asks how effective anthrax can be as a weapon of terror and how easy it is to spread the disease.
Prague, 15 October 2001 (RFE/RL) -- The anthrax scare began in early October when a journalist in the southern U.S. state of Florida contracted the inhaled form of the disease and died.
Seven of his colleagues tested positive for exposure and cases of anthrax-tainted mailings -- anthrax spores sent through the postal system -- were then confirmed in New York and the western U.S. state of Nevada.
Fresh cases in the past three days have brought to 12 the number of people in the U.S. who either have been infected with anthrax or have been exposed to it.
And that's not counting the numerous scares -- all so far groundless -- that have evacuated buildings and airplanes from Britain to Australia.
U.S. Health Secretary Tommy Thompson says the cases in New York, Florida, and Nevada are instances of bio-terrorism. But there's no word yet on whether they are the work of the terrorist organization Al-Qaeda, the group suspected of being behind the 11 September suicide attacks on New York and Washington.
Russian health authorities today said Russia was ready to supply the United States with vaccines against anthrax if necessary.
As fears of anthrax attacks grip the United States and other countries, experts say the threat has to be put into perspective. They say anthrax is not contagious. It's also difficult to disperse in such a way that would infect many people at once. And doctors are now aware of the threat, meaning that prompt diagnosis and treatment are now more likely.
This is how New York City Mayor Rudolph Giuliani put it yesterday: "A balance has to be struck here between sufficient precautions and making people so frightened and so upset that they're not able to conduct their lives, which means having people walking around in space suits all over the city of New York. The reality is that, I think, that they balance that correctly, and also part of the procedure is to have people tested immediately and then, if miniscule amounts are found as were found here, then treat them as a prophylaxis immediately -- and that is, I take it, a 100-percent safe way to proceed."
Anthrax, which occurs naturally, can take three forms in human beings. The most common is cutaneous, or skin anthrax, which is generally found in people who work with animals or animal hides. The spores penetrate the skin through cuts or abrasions and form recognizable black-centered sores.
Another way of contracting the disease is to eat infected meat and develop gastrointestinal anthrax.
The inhalation form -- as in the case of the man in Florida -- is usually fatal, but extremely rare. The last case in the U.S. happened in the late 1970s.
Alastair Hay is professor of toxicology at Leeds University with a special interest in chemical and biological warfare. Hay says the inhalation form of anthrax is harder to diagnose, as usually the first clue that someone is infected is when he or she becomes sick. And even then the symptoms are similar to flu.
He notes the difference between being exposed to the bacteria and being infected: "Not everybody who is exposed to the anthrax spores develops anthrax poisoning. The spores have to get into the body in the first place -- that's either through the skin, through the gut, or in through the lungs. But you require a certain quantity of spores before someone becomes infected with anthrax and the bacteria multiply out of control and produce toxins. The body's natural immunity can deal with a low quantity of spores, and it's only when that immunity is overloaded with a higher concentration of spores that the clinical condition of anthrax develops."
This, Hay continues, is what makes it difficult to infect large numbers of people at once.
"The difficulty anybody has in trying to release anthrax in the air is to get the spores into a form on particles of some sort of liquid aerosol so that those particles are taken into the lung and retained in the lung. It isn't easy to achieve that activity and that sort of spread, as the generation of that aerosol is difficult. In my view, it's unlikely that there would be significant major outbreaks of anthrax poisoning. The ideal way would be to generate an aerosol and fly over a city and release anthrax, and that's just not going to happen. People don't have those opportunities or access to the airspace, let alone the technology that you need for that sort of efficient dispersal of the aerosol."
One of the immediate questions posed by the spate of anthrax-tainted mailings is: Where did the bacteria come from?
Kazakhstan has denied U.S. media reports about the possibility of an anthrax strain from a former Soviet bacteriological-weapons factory in Kazakhstan falling into the hands of extremists.
Hay says that there are some 1,500 reference samples of anthrax around the world designed to enable hospital laboratories to identify the bacteria in cases of suspected infection.
"It's possible that someone obtained an initial stock from one of these reference collections and then cultured up sufficient anthrax and allowed it to develop spores and that was the way the material was mailed. It might have come from an environmental source, someone aware that anthrax was causing disease in a particular country. Many countries in the world have outbreaks of the skin, or cutaneous, anthrax, so someone might have chosen to go to one of those areas and cultured up the bacteria. But you'd still have to go through quite a few laboratory steps to get to the point where you have decent and viable spores which you could use to infect somebody. The third possibility is that it could be from a rogue state involved in an illegal biological-weapons program."
Alison Dale is a specialist in biochemical warfare at the Centre for Defence Studies in London. She says it would have to be a highly organized terrorist group -- whether Al-Qaeda or another organization -- to be behind all the infected letters.
"If we're looking at a terrorist group, what they would need is the knowledge, in terms of biotechnology, of how to extract naturally occurring anthrax and maintain it at the right environmental conditions. This is not a job that's easily done, so we're looking at a group with the time, expertise, and money to put together the right laboratory equipment to maintain the anthrax spores at the right conditions and be able to transfer them into a state where they could be dispersed either through an aerosol spray or, as has been reported in America, releasing the spores into people's mail."
Hay says it's understandable that the anthrax cases have received wide attention and caused much concern. But he says there's need for perspective: "I think that the message that needs to be got over to people is that the likelihood of there being significant numbers infected through any kind of activity is small, that if people are infected, doctors are aware that this is a possibility, that there is treatment available, and that the treatment is in fact effective -- and that once doctors are aware that anthrax poisoning could occur through the inhalation route the inhalation form of the disease is going to be treated much more promptly now as well. And there is information available for doctors on how to recognize inhalation anthrax, so I think it is a case of getting it into proportion."
He says the relative danger to health posed by anthrax is small compared with everyday things that people do, such as driving, sunbathing, and smoking.