Anthrax is caused by bacillus anthracis. The three clinical descriptions of anthrax are: inhalational, cutaneous (skin), and gastrointestinal. Below are the routes of exposures of anthrax and their symptoms.

Inhalational anthrax: This generally requires a dose of fine powder particles (1-5 microns in size) to get into the lungs. Although it is considered technologically difficult to disperse anthrax into particles of this size, several cases of inhalational anthrax have been diagnosed here in the U.S. Investigations regarding the sources of these infections is occurring ongoing and not all sources have been identified to date. The knowledge about anthrax is evolving as this is a new and emerging problem.

Cutaneous anthrax is probably the more likely form of anthrax that could be caused by anthrax-contaminated letters and packages that do not have an aerosolizing device or material. Cutaneous anthrax has an excellent prognosis when diagnosed and treated promptly.

To acquire gastrointestinal anthrax one must eat raw or undercooked contaminated meat. Anthrax is not contagious. It is not transmissible person to person. There is no need to isolate someone with suspected or diagnosed anthrax.


Inhalational: Initially may have mild fever, muscle aches and malaise. This may progress to respiratory failure and shock. Meningitis may develop.

Cutaneous: Skin lesion that begins as a papule, evolves through a vesicular (small blister) phase, and turns into a depressed black eschar (ulcer). The lesion is usually painless. The person may have fever, malaise, headache, and regional enlarged lymph nodes.

Gastrointestinal: May be in the oropharynx or the lower bowel. May have lesions at the base of the tongue, difficulty swallowing, fever, regional enlarged lymph nodes, nausea, loss of appetite, abdominal pain, bloody diarrhea, vomiting of blood.


If an employee receives a threat about anthrax or sees a suspicious letter, package, or powder, he/she needs to follow the hospital policies and procedures. These include: leave the area, prevent others from entering the area, and call 911 from the UC Davis phones or if you are in an offsite UC Davis office call 734-2555. If the employee gets a suspicious material or power on his/her skin, he/she should wash it off with soap and water only. Testing and treatment is based on the type of exposure, e.g. inhalational versus cutaneous, symptoms, and diagnosis. If the substance or powder is tested and does not contain anthrax, or is deemed as not suspicious, no testing or treatment for anthrax is needed. Obtaining nasal swabs of people with no symptoms and no documented exposure to anthrax is not indicated or recommended in the majority of scenarios.

Work status

Anthrax is not contagious. Any work restrictions will be based on the illness severity and will be determined by the treater. If the employee is not exposed/infected with anthrax at work, he/she needs to be evaluated by his/her personal physician.


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