Anthrax is a bacterial disease caused by Bacillus anthracis. It can affect all warm-blooded animals and was known as woolsorters disease as it would commonly affect workers dealing with sheepís wool.
The anthrax bacterium is covered with a tough outer coat, meaning that its spores can live in the soil for decades. Infection can occur from handling wool or hair from diseased animals, inhaling contaminated soil particles, or from eating undercooked meat from animals affected by the disease. This accounts for the three presentations of the illness.
Primarily it is an occupational disease affecting people who work with dead animals and those exposed to wool and hair.
- Inhalation (pulmonary). This is the most dangerous form of anthrax. Cutaneous and gastrointestinal forms are treatable with penicillin, or tetracycline.
Anthrax vaccine has been available since the 1970ís for high-risk individuals. These include animal workers, vets, and people who work in laboratories handling anthrax and the armed forces. An initial course consists of three doses followed by yearly boosters.
Why has it been developed as a potential germ warfare agent?
The tough outer coating means that it can survive in soil or laboratory conditions for years in the spore form. It is colourless and odourless and so is not easily detected. Finally, if spread as a germ warfare agent, it would cause the inhalation form of the disease, which is the most deadly and difficult to treat,
How does it present?
The incubation period is 1-6 days and symptoms of the inhalation type include
It can be diagnosed by:
- Viral-like aches & pains
- Fever, malaise, fatigue, cough and mild chest discomfort followed by severe difficulty breathing
- Isolating the bacteria from blood, other body fluids or skin lesions
- Blood culture
- Measuring specific antibodies late in the course of the disease
Treatment is usually not effective after symptoms are present in the inhalation form. However, ciprofloxacin together with one or two other antibiotics is used. High dose antibiotic treatment after symptoms appear can lower the death rate from 99% to about 80%. Treatment needs to be continued for 60 days.
What happens in inhalation anthrax?
- The spores enter lungs and migrate to the lymph nodes. Here they change to active bacteria, multiply and produce toxins (poisons).
- These toxins cause bleeding and destroy the structures in the middle of the chest. The medical term for this is hemorrhagic necrotizing mediastinitis.
- Anthrax is not thought to be transmissable person to person and immunity is usually gained after any infection.
Health Protection Agency
This article published on
01 July 2005
Next review date 7/1/2013