Anthrax is an acute infectious disease caused by Bacillus anthracis. It is usually a disease of domesticated and wild animals. Humans become infected when brought into contact with diseased animals and their products such as hides, bristles, or wool. It is common in essentially all areas where livestock are raised.

Humans become infected by coming into contact with the spores (offspring of the microbe, can survive in soil for years), through 3 ways:

1. Skin (cutaneous)

A minor scratch or abrasion, usually on an exposed area is inoculated by spores from the soil or a contaminated animal or carcass. The spores germinate, vegetative cells multiply fast, and a characteristic gelatinous edema develops at the site.

This develop into papule within 12-36 hours after infection. The papule changes rapidly to a vesicle, then a pustule, and finally into a necrotic ulcer from which infection may disseminate, giving rise to septicemia. Lymphatic swelling also occurs within seven days. In severe cases, where the blood stream is eventually invaded, the disease is frequently fatal.

Itching at the site of infection, followed by formation of lesion (ulcer) with a black, necrotic (dying tissue) eschar (scab). About 20% of untreated cases of cutaneous anthrax will result in death.

2. Gastointestinal

Anthrax can be spread by eating undercooked meat from infected animal. This consumption 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% to 60% of cases.

3. Respiratory tract (Inhalation)

Inhalation anthrax, or Woolsorter's disease, which results most commonly from inhalation of dust where animal hair or hides are being handled.

Initial symptoms are low grade fever, a dry cough, and weakness, resembling a common cold.. The person may briefly improve after 2 - 4 days, but within 24 hours respiratory distress occurs with shock and death following shortly thereafter.

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.

Doctors usually prescribe effective antibiotics like penicillin, erythromycin, tetracycline, and chloramphenicol. To be effective, treatment should be initiated early. If left untreated, the disease can be fatal.

The anthrax vaccine for humans licensed for use is a cell-free filtrate vaccine, which means it uses dead bacteria as opposed to live bacteria. It is usually for individuals who come in contact in the workplace with imported animal hides, furs, wool, animal hair, bristles, etc; and for individuals engaged in diagnostic or investigational actives which my bring them into contact with anthrax spores.