What is anthrax?

Anthrax is an acute infectious disease caused by the bacterium Bacillus anthracis. The disease most commonly occurs in animals and can also infect humans.

How common is anthrax?

Anthrax is infrequent in most industrialized countries. It is most common in agricultural regions where anthrax in animals is common. When anthrax affects humans, it is usually an occupational hazard of agriculture and wildlife workers who handle infected animals. Anthrax is very rare in Hong Kong. There was only one reported case in past 10 years.

How is anthrax transmitted?

Anthrax organisms can cause infection in the skin, gastrointestinal tract, or the lungs. To do so, the organism must be rubbed into abraded skin, swallowed, or inhaled as a fine, aerosolized mist. The disease can be prevented after exposure to the anthrax spores by early treatment with the appropriate antibiotics. For anthrax to be an effective agent in biological warfare, it must be aerosolized into very small particles. This is difficult to do, and requires a great deal of technical skill and special equipment.

Can anthrax spread from person to person?

Transmission from person to person is very rare.

What are the symptoms of anthrax?

Symptoms vary depending on how the disease is contracted. Symptoms usually occur within a few hours to 7 days after exposure.

Cutaneous anthrax: Occurs when the bacterium enters skin wounds. It begins as a raised itchy lesion and develops into a painless ulcer with a black center. Lymph glands in the adjacent area may swell. The disease is readily cured with appropriate treatment.

Inhalation anthrax: Initial symptoms resemble a common cold. After several days, severe breathing problems and shock may develop. Inhalation anthrax without early treatment is usually fatal.

Intestinal anthrax: Initial symptoms include nausea, loss of appetite, vomiting, abdominal pain, fever, and severe diarrhoea. Intestinal anthrax can be fatal without early treatment.

How can anthrax be treated?

Anthrax can be prevented after exposure to anthrax spores by early treatment with the appropriate antibiotics. Treatment should be given and supervised by a doctor.

Department of Health
19 October 2001