Anthrax spores can induce three types of illness, depending on how they make contact with the human body.
- Victims breathe in spores floating through the air; the spores then lodge in their lungs.
- Certain cells take the spores to the lymph nodes surrounding the lung. Once they enter the lymph nodes, the spores germinate into bacteria and cause inflammation and enlargement of these lymph nodes.
- Anthrax bacteria then spread from the lymph nodes to sites throughout the body and produce a toxin that can be destructive to organs and is difficult to treat.
- Symptoms can occur within seven days of infection or can take up to 42 days to appear. These symptoms include:
- Fever (temperature greater than 100 degrees Fahrenheit); may be accompanied by chills or night sweats
- Flulike symptoms
- Cough, usually a nonproductive cough; chest discomfort; shortness of breath; fatigue; or muscle aches
- Sore throat, followed by difficulty swallowing; enlarged lymph nodes; headache; nausea; loss of appetite; abdominal distress; vomiting; or diarrhea
- Inhalational anthrax is the most lethal form of an anthrax illness.
- Inhalational anthrax was the cause of all five deaths in the 2001 U.S. postal system attacks.
- Some patients treated with antibiotics can have an initial recovery followed by a relapse once antibiotic therapy has been terminated.
- Inhalational anthrax, like most diseases, is more deadly for people with compromised immune systems.
- Untreated inhalational anthrax has a 90 percent mortality rate.
- The survival rate for inhalational anthrax victims depends on quick diagnosis and treatment with antibiotics.
- The mortality rate is still approximately 75 percent, even with antibiotics.
Anthrax spores enter the body through an open wound or cut, or even through microscopic breakdowns of the skin.
- Symptoms appear within one to seven days after exposure.
- A small sore quickly develops into a blister.
- The blister becomes a skin ulcer, or eschar, and ultimately develops a black scab in the center.
- The sore, blister, and ulcer do not hurt and initially look like a spider bite.
- Cutaneous anthrax is the least deadly form of anthrax.
- The survival rate is 80 percent without treatment and more than 99 percent with treatment.
Gastrointestinal anthrax occurs when anthrax is ingested, usually through meat from anthrax-infected animals.
- First signs of the infection appear within two to five days of exposure.
- Initial symptoms include nausea and loss of appetite.
- Later symptoms include bloody diarrhea, fever, and severe stomach pain.
- Symptoms mirror those for stomachflu, food poisoning, and appendicitis.
If untreated, at least 25 percent of gastrointestinal anthrax cases lead to death.
- To treat someone with an anthrax illness successfully, it must be diagnosed early.
- Early diagnosis is complicated because there is no single screening test to confirm anthrax illness.
- Exposure is confirmed by isolating the anthrax bacteria from the blood, skin lesions, or respiratory secretions or by measuring specific antibodies in the blood.
- Blood tests to confirm an anthraxinfection can take up to 72 hours, since it takes time to isolate a particular bacterium in a blood sample. Some circumstances may produce test results much more quickly. For example, in a severe inhalational case, there may be a large concentration of bacteria in a sample, which may allow technicians to obtain a result in a few hours.
- If inhalational anthrax is suspected, physicians typically obtain a chest X-ray and a CAT scan to confirm their suspicions.
- Nasal swabs can detect the presence of spores but are not a diagnostic tool. A positive swab does not mean a person will develop an anthrax illness and a negative swab does not mean a person will not develop an anthrax illness.
- A nasal swab is only an indicator of whether anthrax spores are present in an area.