Anthrax
Anthrax & Bioterrorism
Michigan Department of Community Health Bureau of Epidemiology Division of Communicable Disease and Immunization
Biological Weapon
- Several nations are believed to have offensive biological weapons programs. Iraq has acknowledged producing and weaponizing anthrax.
- Experts believe that the manufacture of a lethal anthrax aerosol is beyond the capacity of individuals groups without access to advanced biotechnology.
- In 1979, an accidental aerosolized release of anthrax in the former Soviet Union resulted in at least 79 cases of anthrax infection and 68 deaths.
- Estimates of cases and deaths following the theoretical aircraft release of anthrax over an urban population predicts millions of deaths.
The Disease
- Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in warm-blooded animals and can therefore infect humans.
- Symptoms of disease vary depending on how the disease was contracted, but symptoms usually occur within seven days of exposure.
- Initial symptoms of inhalation anthrax infection may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. Inhalation anthrax usually results in death in 1 to 2 days after onset of the acute symptoms.
- another defining symptom of inhalation anthrax can be found in the identification of a widened mediastinum on chest radiograph.
- 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, and fever are followed by abdominal pain, vomiting of blood, and severe diarrhea. Intestinal anthrax results in death in 25% to 60% of cases.
The Risk
- Although anthrax can be found globally, it is more often a risk in countries with less standardized and effective public health programs. Areas currently listed at high risk naturally occurring anthrax are South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East.
- Director person-to-person spread of anthrax most likely does not occur.
- Early diagnosis of inhalation anthrax would be difficult and would require a high index of suspicion. The first evidence of a clandestine release of anthrax as a biological weapon most likely will be patients seeking medical treatment for symptoms of inhalation anthrax.
- There is not need to immunize or treat contacts (e.g., household contacts, friends, coworkers) of a patient, unless they were also exposed to the aerosol at the time of the attack.
- Serious consideration should be given to cremation of persons who die to prevent further transmission of the disease.
Treatment
- Anthrax is diagnosed by isolating B anthracis from the blood, skin lesions, or respiratory secretions or by measuring specific antibodies in the blood of suspected cases.
- Given the rapid course of symptomatic inhalation anthrax, early antibiotic use is essential - a delay, even in hours, may lesson chances for survival. For those treated with antibiotics and surviving, the risk of recurrence remains for at least 60 days without a course of vaccination.
- Doctors can prescribe effective antibiotics. Usually penicillin is preferred when the organism is found to be susceptible. Erythromycin, tetracycline, ciprofloxacin, doxycycline or chloramphenicol can also be used. Antibiotic regimens commonly recommended for the treatment of sepsis have not been studied extensively in treating humans for inhalation anthrax. However, it is important to note that to be effective, treatment should be initiated early.
- The anthrax vaccine for humans licensed for use in the United States is a cell-free filtrate vaccine, which means it uses dead bacteria as opposed to live bacteria. The vaccine is reported to be 93% effective in protecting against cutaneous anthrax. The vaccine is not currently available to the general public. (Anthrax vaccines intended for use in animals should not be used in humans.)
- The vaccine should only be administered to healthy men and women from 18 to 65 years of age.
Source: Centers for Disease Control and Prevention. Reuse or reproduction of this material is authorized.