What is anthrax?
Anthrax is a colorless, odorless, tasteless bacterium that protects itself from sunlight, heat and disinfectant by forming a protective coat. With this coat, the bacterium is called a "spore." The spores are so small that even 8,000-10,000 spores appear smaller than a speck of dust. This is the amount that animal studies suggest could be required for a lethal dose, although scientists are considering a much smaller dose could cause anthrax in people.
If inhaled, anthrax spores can germinate and lead to infection within one to 60 days. This is pulmonary anthrax, which usually causes death.
Less lethal forms include cutaneous infections, which occur if anthrax spores come in contact with a cut or other opening in the skin.
Another form of anthrax develops in the intestine of those who eat improperly cooked meat of animals that have been infected with anthrax.
All three forms of anthrax disease can be caused by the same bacterium — Bacillus anthracis.
Is anthrax contagious?
Inhalation anthrax does not spread from person to person. It is a "one-time agent" — to catch it a person must come directly in contact with the bacterium. Cutaneous anthrax can be transmitted in the rare instance that a cut or other opening in a person's skin comes in direct contact with the drainage from an open sore.
What are the symptoms of anthrax?
Symptoms of pulmonary anthrax are very similar to the flu, which can make an initial diagnosis somewhat difficult. However, in light of recent events many doctors have a heightened awareness of the possibility, and are therefore more likely to diagnose it.
Symptoms of the disease vary depending on how the disease was contracted, but usually occur within seven days. Officials at the Centers for Disease Control list the following:
Cutaneous: Most (about 95 percent) anthrax infections occur when the bacterium enters a cut or abrasion on the skin, such as when handling contaminated wool, hides, leather or hair products (especially goat hair) of infected animals. Skin infection begins as a raised itchy bump that is dark in color and resembles an insect bite but within 1-2 days develops into a vesicle and then a painless ulcer, usually 1-3 centimeters in diameter, with a characteristic black area in the center. Lymph glands in the adjacent area may swell. About 20 percent of untreated cases of cutaneous anthrax will result in death. Deaths are rare with appropriate therapy.
Inhalation: Initial symptoms may resemble a common cold. These symptoms may actually then retreat for a short period. But after several days, the symptoms progress to severe breathing problems and shock. Inhalation anthrax is usually fatal.
Intestinal: The intestinal disease form of anthrax may follow the consumption of contaminated meat and is characterized by an acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting, fever are followed by abdominal pain, vomiting of blood, and severe diarrhea. Intestinal anthrax results in death in 25 percent to 60 percent of cases.
How is anthrax infection diagnosed?
For people with suspected anthrax disease, the CDC lists a number of laboratory testing that can identify the disease. Tests can include:
Taking cultures of blood and spinal fluid to detect antibodies to the disease. These tests should be done before antibiotic treatment has been initiated.