Anthrax can be an insidious and efficient killer. Its spores can survive for decades. If inhaled, they can kill in a matter of two or three days, doing its worst damage with symptoms that seem no worse than a cold.
The military considers anthrax to be the most serious of all biological threats. But to be so dangerous, anthrax must be ``weaponized,'' manufactured in the form of fine spores that can be breathed deep into the lungs.
Here are answers to questions most often asked about this microbe.
Q: What does anthrax look like?
A: In its most destructive form _ an aerosol sprayed into the air _ it is invisible and odorless. Anthrax spores can only be seen through a microscope that magnifies 50 to 100 times. Scientists say it can be stored in bulk as a powder, liquid or paste.
Q: Would I know if I breathed anthrax?
Q: If anthrax is on the ground, can I get it from kicking up dust?
A: Probably not. The spores tend to clump together, so even if inhaled, they do not get deep into the lungs.
Q: How much anthrax does it take to make someone sick?
A: Roughly 10,000 spores.
Q: Where do anthrax spores come from?
A: Anthrax bacteria live in the blood of animals. When an animal dies, the bacteria form spores, which are released.
Q: What happens when a person breathes them?
A: The spores become lodged in the lungs. There, they are picked up by immune-system cells called macrophages, which carry them to the lymph nodes. On the way, the spores mature into bacteria.
Q: How do they make people sick?
A: The bacteria multiply in the lymph nodes and then enter the bloodstream. They produce a poison that causes the immune system to produce lethal doses of chemicals that are ordinarily useful to the body.
Q: What are the symptoms?
A: At first, they seem like a cold or flu: fever, ache and nonproductive cough. Plummeting blood pressure, swelling, hemorrhaging and other catastrophic symptoms soon follow.
Q: How quickly does it kill?
A: Typically within three days of the start of symptoms.
Q: How soon do symptoms start once people breathe the spores?
A: Usually around 10 days, but up to six weeks.
Q: Can it be treated?
A: It can be treated with antibiotics, such as Cipro or doxycycline, if given before symptoms start. Treatment usually fails once symptoms set in, since it does no good to kill the bacteria once they make large amounts of toxin.
Q. Isn't there a vaccine to prevent it?
A. The only vaccine is in limited supply and is now only available to the military.
Q: Are there other forms of anthrax disease?
A: Yes. By far the most common is anthrax on the skin, which forms inflamed bumps. It can be fatal but usually goes away on its own. This form most often infects people who handle livestock.
Q: How can anthrax spores be killed?
A: They can live for many years in the ground and resist drying, heat and ultraviolet light. They can be killed with a mixture of bleach and water or with vaporized formaldehyde.
Q: Where would someone get anthrax?
A: Anthrax is grown and maintained in cell cultures that are kept by research labs. It is not sold or otherwise legally distributed. Theoretically, anthrax could be isolated and grown from the remains of an animal that died of anthrax or from nearby soil. Several countries have produced large quantities of anthrax as weapons.
Q: How long has anthrax been around?
A: Anthrax is thought to have been one of the Egyptian plagues at the time of Moses. The ancient Romans recorded cases.
Q: How does it get its name?
A: It comes from the Greek word for coal. It's called this because of the black scab it leaves on the skin.