anthrax

  • related: Infectious Disease

  • Cause: Bacillus anthracis spores (Figure 15 panel A and Figure 15 panel B). Spores may be spread by aerosolization or in the mail, with infection following inhalation. Infection may also occur by cutaneous contact, with a characteristic black eschar forming (Figure 15 panel C), or by ingestion. Person-to-person transmission does not occur.

  • Sx: malaise, myalgia, fever, cough, dyspnea, and substernal chest discomfort. Meningitis occurs in up to 50% of persons. Rapid clinical deterioration leads to shock and death.

  • Dx:

    • no test available for asymptomatic person
    • PCR blood, tissues, fluid
    • CXR: widened mediastinum (Figure 15 panel D).

  • Rx: Treatment is outlined in Table 40. Toxin-neutralizing human monoclonal antibodies and anthrax immune globulin are approved for treatment and prevention of inhalation anthrax in conjunction with antibiotics. Postexposure prophylaxis consists of a fluoroquinolone or doxycycline in conjunction with vaccination.

Because this patient has no known direct exposure to anthrax, no treatment is necessary. In cases of proven or suspected anthrax in a family member, no specific treatment or isolation procedures are required for others in the household because spread in health care or household settings has never been demonstrated. In patients with confirmed or suspected bioterrorism-related anthrax exposure, postexposure prophylactic antibiotics, taken for 60 days, should be started as soon as possible. Ciprofloxacin, levofloxacin, and doxycycline are the approved drugs for postexposure prophylaxis in adult patients. In pregnant women, ciprofloxacin is the drug of choice, and although tetracyclines are not recommended during pregnancy, doxycycline can be used with caution when ciprofloxacin is contraindicated. Therapy can be completed with amoxicillin if the isolate is found to be penicillin susceptible. Because of the possibility that residual dormant spores may become active after antibiotics are completed, three subcutaneous injections of anthrax vaccine should be given at 2-week intervals as part of postexposure prophylaxis.

No test is available for the detection of anthrax infection in an asymptomatic person, so taking a swab or performing a blood test would provide no useful information.