There is some evidence that the Japanese used anthrax as a biological weapon (BW) in China during World War II (Christopher GW, et al. Biological warfare: A historical perspective. JAMA 1997; 278 (Aug 6): 412-17).
Since then, several countries are believed to have incorporated anthrax spores into biological weapons. Intelligence analysts believe that at least seven potential adversaries have an offensive BW capability to deliver anthrax -- twice the number of countries when the 1972 Biological and Toxin Weapons Convention (BTWC) took effect. The BTWC was designed to prohibit such activity.
Iraq admitted to the United Nations in 1995 that it loaded anthrax spores into warheads during the Gulf War. In the post-cold war era, the former Soviet Union admitted to having enough anthrax on hand to kill every person on the planet several times over. The accidental aerosolized release of anthrax spores from a military microbiology facility in the former Soviet Union city of Sverdlovsk in 1979 resulted in at least 79 cases of anthrax infection and 68 human deaths and demonstrated the lethal potential of anthrax aerosols. Members of Aum Shinrikyo, the group responsible for the 1995 Tokyo sarin attack, reportedly experimented with biological agents in Japan before resorting to chemical agents. A lengthy article in the May 26, 1998, edition of the New York Times reported that members of Aum Shinrikyo released anthrax spores and botulinum toxin in Tokyo, Yokohama, and Yokosuka in 1990, targeting Japanese government and U.S. Navy facilities. Fortunately, no one was injured in these events.
Anthrax spores have also been used as a weapon inside the United States by unknown terrorists in the Fall of 2001. The attack killed 5 people and infected at least 17 others.
Anthrax is a rapidly progressing acute infection caused by spore-forming bacteria called Bacillus anthracis. Anthrax most commonly occurs in warm-blooded animals, especially goats, cattle, and sheep, but it can also infect humans. Anthrax spores can be easily produced in a dry form for biological weapons. Spores can survive many years in adverse conditions and still remain capable of causing disease. When inhaled by humans, these spores cause respiratory failure that can lead to death within a week.
Anthrax can make an excellent weapon of mass destruction. The spores may be used as a weapon in a variety of delivery systems. They can be produced in large quantities without sophisticated equipment. All it takes is a single breath of aerosolized anthrax to inhale enough spores to cause the disease. Then, if serious symptoms occur, it kills 99% of unprotected people. Even if a person with symptoms receives antibiotics, the death rate is still about 50%. Anthrax spores are odorless, colorless, and tasteless.
A nasal swab involves placing a swab inside the nostrils and taking a culture. The CDC and the U.S. Department of Health and Human Services do not recommend the use of nasal swab testing by clinicians to determine whether a person has been exposed to Bacillus anthracis, the bacteria responsible for anthrax, or as a means of diagnosing anthrax. At best, a positive result may be interpreted only to indicate exposure; a negative result does not exclude the possibility of exposure. Also, the presence of spores in the nose does not mean that the person has inhalational anthrax. The nose naturally filters out many things that a person breathes, including bacterial spores. To have inhalational anthrax, a person must have the bacteria deep in the lungs, and also have symptoms of the disease.
Another reason not to use nasal swabs is that most hospital laboratories cannot fully identify anthrax spores from nasal swabs. They are only able to tell that bacteria that resemble anthrax bacteria are present.