Anthrax, Then and Now (cont.)

How easy is it to get an anthrax infection?

Not very easy! Since only the spores can spread (transmit) the disease and anthrax does not form spores in living tissues, the disease is not transmitted from person to person. That is to say, anthrax is not contagious. The most common way people get infected with anthrax is by working with animal carcasses or hides that contain spores. These people usually contract cutaneous anthrax.

Inhalation anthrax is exceedingly rare. This is because, as previously mentioned, the spores have to travel all the way to the tiny air sacs (alveoli) in the lungs. Thus, the spores must be small (less than 5 microns) and able to get past many protective barriers (such as mucus, body chemicals, and microscopic hairs) in the mouth, nose, throat, and air passages. What's more, the spores must overcome obstacles presented by the body's immune (defense) system. So, it is estimated that many thousands of spores (perhaps 10,000-20,000) are needed to establish an infection in humans. All things considered, most forms of anthrax bacteria are probably not that dangerous. Sadly, however, some governments and terrorist groups are spending millions of dollars to try to develop more deadly anthrax bacteria for use as biologic weapons. Anthrax is easy to grow. Anthrax bacteria are very resistant to destruction. Thus, when released into the air, they can spread over large distances and affect many people. It is not surprising, and it is somewhat reassuring, that major efforts are ongoing to find the best ways to prevent, detect, and treat future bioterrorist attacks using anthrax.

Last Editorial Review: 4/10/2007