Anthrax
Anthrax is a bacterial infection caused by Bacillus anthracis. It primarily affects livestock but can occasionally spread to humans, affecting theskin, intestines, or lungs. In humans, the infection can be treated, but it is almost always fatal in animals.
Anthrax is often fatal to cattle, sheep, and goats, and their hides, wool, and bones are often heavily contaminated. In humans, the disease is almost always an occupational hazard, contracted by those who handle animal hides (farmers, butchers, and veterinarians) or sort wool. It is also possible to becomeinfected with anthrax by eating meat from contaminated animals. There are noreports of the disease spreading between people.
Symptoms vary depending on how the disease was contracted. They usually appear within one week of exposure. In humans, anthrax most frequently occurs whenthe bacteria enter a cut or abrasion. Cutaneous anthrax, as this infection is called, is the mildest form of the disease. The first symptom is an itchy,raised area like an insect bite. Within one to two days, the area becomes inflamed. Next, a blister forms around the dying tissue which becomes black in the center. Other symptoms may include shivering and chills. The bacteria usually remain within the sore. In rare cases, they may spread to nearby lymph nodes or escape into the bloodstream), causing fatal blood poisoning.
Inhaling the bacteria can lead to a rare, fatal form of anthrax known as pulmonary or inhalation anthrax that attacks the lungs, sometimes spreading to the brain. Inhalation anthrax begins with flu-like symptoms: fever, fatigue, headache, and shortness of breath. Symptoms progress to bronchitis, and it becomes difficult to breathe. Finally, the patient enters shock. This form of anthrax is usually fatal.
Intestinal anthrax is rare and often fatal. It is caused by eating meat froman animal that died of anthrax. Intestinal anthrax causes stomach and intestinal inflammation and sores or lesions. The first signs of disease are nauseaand vomiting, loss of appetite, and fever, followed by abdominal pain, vomiting of blood, and severe bloody diarrhea.
Anthrax is diagnosed by detecting B. anthracis in blood, skin lesions,or respiratory secretions. The bacteria may be positively identified using biochemical methods. Blood samples will indicate elevated antibody levels (increased amounts of a specific protein produced in response to anthrax infection).
In the early stages, anthrax is curable with high doses of penicillin. Othercommonly used antibiotics are also effective.
Death is unlikely with appropriate care. Ten to twenty percent of patients will die from cutaneous anthrax if it is not properly treated. All patients with inhalation anthrax will die if untreated. Intestinal anthrax is fatal 25-75% of the time.
Anthrax is relatively rare in the United States because of widespread animalvaccination and practices used to disinfect hides or other animal products. For those in high-risk professions, an anthrax vaccine is available that is 93% effective in protecting against infection.
Other means of preventing the spread of infection include carefully handlingdead animals suspected of having the disease and providing good ventilation when processing hides, fur, wool, or hair. Anyone visiting a country where anthrax is common or where herd animals are not vaccinated should avoid contactwith livestock or animal products and avoid eating meat that has not been properly prepared and cooked.
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