- The Washington Times - Thursday, October 18, 2001

Anthrax strikes in three ways: by inhalation, digestion or through a cut in the skin.
The deadliest and the only one used as a bioterrorism weapon is inhaled anthrax. It is most easily transmitted in a powdery or mist form, because it spreads quickly and invisibly over a large area, resulting in death or illness.
Fatal 99 percent of the time without treatment, it develops when spores enter a person's lungs, migrate to the lymph nodes, change to the bacterial form, multiply and produce toxins. These toxins cause bleeding and destruction of structures in the middle of the chest.
The infection is particularly dangerous because, unless tested, a person won't know he has it for one to six days, while the bacteria incubate.
If it is detected before the symptoms, like coughing and fatigue, surface, anthrax can be treated with antibiotics. Once the signs surface, death occurs within 24 to 48 hours. Taking high doses of antibiotics is somewhat effective, reducing the mortality rate from 99 percent to 80 percent.
It is not contagious.
"A person-to-person spread has never been discovered for anthrax," said Dr. Michael Donnenberg, head of the division of infectious diseases at the University of Maryland School of Medicine.
Anthrax is high on the Defense Department's list of bioterrorism threats because it is easy and inexpensive to make in large quantities. It can be grown in a laboratory from a starter culture and can be stored almost indefinitely as a dry powder.
But it is harder to infect people with it.
"In the past it's been believed you had to have a pretty high sophistication to produce anthrax that would be weapon grade, that could be aerosoled," said Dr. Timothy Flaherty, chairman of the board of trustees for the American Medical Association. "Generally, it's believed it's not something you can make in your garage or basement."
Anthrax spores must be microscopic for the bacteria to enter the lungs, Dr. Donnenberg said. Bigger particles can get stuck in the nose or nose hair, eliminating the threat of infection.
The anthrax sent in an envelope to Senate Majority Leader Tom Daschle's office, for instance, was in the proper concentration to cause serious damage, health officials said.
"It has to be dried and milled, and broken up into smaller particles, so that it can than be aerosoled more easily, so the potential of having it inhaled would be greater," Dr. Flaherty said.
A 1993 analysis by Congress' Office of Technology Assessment estimated that 130,000 to 3 million deaths could occur if 100 kilograms of anthrax spores were released over Washington, making such an attack as lethal as a hydrogen bomb.
The Centers for Disease Control and Prevention estimates that such an attack would carry an economic burden of $26.2 billion per 100,000 people exposed to the spores. The Washington area's population is about 572,000.
But anthrax doesn't always work as a biological weapon, Dr. Donnenberg said. Terrorist group Aum Shinrikyo, which released sarin in a Tokyo subway station in 1995, disseminated anthrax aerosol and botulism throughout Tokyo at least eight times. The attacks failed to produce illness.
"This illustrates that there are technical difficulties with a large-scale attack," Dr. Donnenberg said. "You have to have the right concentration with the right amount of particles and get it to spread over the right area, and worry about things like wind direction and having an apparatus to disperse it with you can't just get on top of the building and open up an envelope and hope it works."
The bacteria can be grown and disseminated in water, but that won't cause human infection, Dr. Flaherty said.
Anthrax also can be contracted through the skin or by eating contaminated animal products.
Gastrointestinal anthrax most often occurs in plant-eating animals that are infected by eating the spores from the soil.
In humans, the infection leads to lesions inside the stomach, which cause nausea, vomiting and acute pain.
Cutaneous anthrax is the most common type of infection, with 95 percent of cases. But it rarely results in death. Even without antibiotic treatment, the mortality rate is about 20 percent.


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