Anthrax
Symptoms
The three kinds of infection vary in their symptoms and prognoses:
The three kinds of infection vary in their symptoms and prognoses:
- Cutaneous anthrax is the most common form and is usually caused by the bacterium getting into a cut or abrasion on the skin, as can happen from contact with contaminated meat, wool, hides, or leather. The incubation period is 1 to 12 days. The infection begins as a bump that looks like an insect bite and within days opens into a painless ulcer with a black area in the center. Nearby lymph glands may swell. About 20% of untreated cases result in death, but death is rare in patients who receive antimicrobial therapy.
- Inhalational anthrax is the most lethal form and is caused by breathing in spores. The incubation period is believed to be 1 to 7 days generally but may range up to 60 days. The initial symptoms resemble those of a viral respiratory illness, including sore throat, mild fever, muscle aches, and malaise. This first stage can last from hours to a few days, and the second stage may develop suddenly, with symptoms including shortness of breath, fever, shock, meningitis, and respiratory failure. The fatality rate is high, about 75% after symptoms begin, even with medical care, including antibiotics.
- Gastrointestinal anthrax, caused by the consumption of raw or undercooked contaminated meat, has an incubation period of 1 to 7 days. The symptoms include severe abdominal distress and fever. The symptoms can be concentrated around either the pharynx (with lesions at the base of the tongue, sore throat, fever, and enlarged lymph nodes) or the lower bowels (with nausea, loss of appetite, vomiting, and fever, followed by abdominal pain, vomiting blood, and bloody diarrhea). The fatality rate is 25% to 60%.
