Anthrax Treatment & Management

Author: Burke A Cunha, MD; Chief Editor: Michael Stuart Bronze, MD more...

Updated: Sep 27, 2011

What would you like to print?

Prehospital Care
Emergency Department Care
Consultations
Approach Considerations
Show All

Prehospital Care

As with any potential epidemic biologic exposure, patients should be decontaminated in the field when possible, and paramedical health care workers should wear masks and gloves. If protection is needed from exposure, responders are advised to use splash protection, gloves, and a full-face respirator with high-efficiency particulate air (HEPA) filters (level C) or self-contained breathing apparatus (SCBA) (level B).

Persons who are potentially contaminated should wash with soap and water, not bleach solutions. Clothing and evidence/materials should be placed in plastic bags (triple). If the contamination is confirmed, then a 1:10 dilution of household beach may be used to decontaminate any materials and surfaces not sufficiently cleaned by soap and water.

Chemoprophylaxis with antibiotics should be instituted only if exposure is confirmed. For persons not at risk for repeated exposures to aerosolized Bacillus anthracis spores through their occupation, preexposure vaccination with anthrax vaccine is not recommended.

Emergency Department Care

The emergency department workup includes rapid initiation of intravenous antibiotic therapy. If risk of exposure is considerable, initiate PEP.

During the 2001 bioterrorist attacks in the United States, the Centers for Disease Control and Prevention (CDC) recommendations for antimicrobial PEP included ciprofloxacin or doxycycline; the CDC recommended amoxicillin for children and pregnant or breastfeeding women exposed to strains susceptible to penicillin. The duration of postexposure antimicrobial prophylaxis should be 60 days if used alone for PEP of unvaccinated exposed persons.

There is a potential preventive benefit of using anthrax vaccine along with an antimicrobial drug for PEP, and the vaccine was made available for this use during the 2001 bioterrorism attacks. However, anthrax vaccine is not licensed for use in PEP.

Patients can be admitted to a normal hospital room with barrier nursing procedures (ie, gown, gloves, mask) and secretion precautions (ie, special handing of potentially infectious dressings, drainage, and excretions).

Consultations

Anthrax is a reportable disease; notify local health care authorities and the Centers for Disease Control and Prevention of suspected cases. In addition, consultation with an infectious disease specialist may be warranted, although treatment of patients in whom anthrax is suspected is straightforward. If biologic terrorism is a threat, consider contacting the Federal Bureau of Investigation (FBI) through the local police department.

Approach Considerations

Treat patients with cutaneous anthrax as outpatients, using oral doxycycline. Alternatively, any quinolone can be used for a total course of 7-14 days.

With doxycycline, a loading regimen should be used (200 mg PO/IV every 12 hours for 72 hours). In severely ill patients, 200 mg IV/PO every 12 hours may be continued (without toxicity) for the duration of therapy. Oral doxycycline and quinolones have excellent bioavailability; the same blood/tissue levels are obtained with PO and IV therapy. Use any quinolone in patients who are unable to take penicillin or doxycycline.

The preferred agent used to treat nonbioterrorist anthrax is penicillin. Penicillin is the preferred agent to treat inhalational anthrax and anthrax meningitis. Use meningeal doses for inhalational anthrax because meningitis is often also present.

For bioterrorist anthrax, use any quinolone or doxycycline for 1-2 weeks. Clindamycin may be added for its anti-exotoxin effect. Use doxycycline or any quinolone (eg, ciprofloxacin, levofloxacin) for postexposure prophylaxis (PEP) to prevent inhalational anthrax. PEP to prevent inhalational anthrax should be continued for 60 days.

Antimicrobial therapy renders lesions culture-negative within hours, but the lethal effects of anthrax are related to the effects of the organism's toxin. Patients with septic and hemorrhagic shock, which is the final common pathway for end-stage anthrax infection, should be admitted to the intensive care unit for hemodynamic monitoring and management. In addition, progressive respiratory insufficiency may necessitate the use of ventilatory support.

Despite early treatment, persons infected with inhalational, gastrointestinal, or meningeal anthrax have a very poor prognosis. Although prophylaxis and vaccinations confer almost complete protection, adequately providing immunity to a potentially exposed community is extremely difficult.

Proceed to Medication

Contributor Information and Disclosures

Author

Burke A Cunha, MD Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital

Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Ronald A Greenfield, MD Professor, Department of Internal Medicine, University of Oklahoma College of Medicine

Ronald A Greenfield, MD is a member of the following medical societies: American College of Physicians, American Federation for Medical Research, American Society for Microbiology, Central Society for Clinical Research, Infectious Diseases Society of America, Medical Mycology Society of the Americas, Phi Beta Kappa, Southern Society for Clinical Investigation, and Southwestern Association of Clinical Microbiology

Disclosure: Pfizer Honoraria Speaking and teaching; Gilead Honoraria Speaking and teaching; Ortho McNeil Honoraria Speaking and teaching; Abbott Honoraria Speaking and teaching; Astellas Honoraria Speaking and teaching; Cubist Honoraria Speaking and teaching; Forest Pharmaceuticals Speaking and teaching

Chief Editor

Michael Stuart Bronze, MD Professor, Stewart G Wolf Chair in Internal Medicine, Department of Medicine, University of Oklahoma Health Science Center

Michael Stuart Bronze, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, American Medical Association, Association of Professors of Medicine, Infectious Diseases Society of America, Oklahoma State Medical Association, and Southern Society for Clinical Investigation

Disclosure: Nothing to disclose.

Additional Contributors

Hilarie Cranmer, MD, MPH, FACEP; Mauricio Martinez, MD; James Li, MD; Barry J Sheridan, DO; Robert G Darling, MD, FACEP

Additional Contributors

Hilarie Cranmer, MD, MPH, FACEP; Mauricio Martinez, MD; James Li, MD; Barry J Sheridan, DO; Robert G Darling, MD, FACEP

References

Inglesby TV, O'Toole T, Henderson DA, et al. Anthrax as a biological weapon, 2002: updated recommendations for management. JAMA. May 1 2002;287(17):2236-52. [Medline].
John TJ, Dandona L, Sharma VP, Kakkar M. Continuing challenge of infectious diseases in India. Lancet. Jan 15 2011;377(9761):252-69. [Medline].
Holty JE, Bravata DM, Liu H, et al. Systematic review: a century of inhalational anthrax cases from 1900 to 2005. Ann Intern Med. Feb 21 2006;144(4):270-80. [Medline].
Akbayram S, Dogan M, Akgün C, et al. Clinical findings in children with cutaneous anthrax in eastern Turkey. Pediatr Dermatol. Nov-Dec 2010;27(6):600-6. [Medline].
Knox D, Murray G, Millar M, et al. Subcutaneous anthrax in three intravenous drug users: a new clinical diagnosis. J Bone Joint Surg Br. Mar 2011;93(3):414-7. [Medline].
Food and Drug Administration. 17.5 FDA-Approved Medication Guide. Levaquin (levofloxacin). Accessed August 6, 2009. Available at http://www.accessdata.fda.gov/drugsatfda_docs/label/2009/020634s053,020635s058, 021721s021lbl.pdf.
CDC. Vaccines and Preventable Diseases:Anthrax Vaccination. Vaccines:VPF-VAD/Anthrax/mainpage. Accessed July 9, 2009. Available at http://www.cdc.gov/vaccines/vpd-vac/anthrax/default.htm#vacc.

Polychrome methylene blue stain of Bacillus anthracis. Image courtesy of Anthrax Vaccine Immunization Program Agency, Office of the Army Surgeon General, United States.

Histopathology of mediastinal lymph node showing a microcolony of Bacillus anthracis on Giemsa stain. Image courtesy of Marshall Fox, MD, Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Cutaneous anthrax. Image courtesy of Anthrax Vaccine Immunization Program Agency, Office of the Army Surgeon General, United States.

Skin lesion of anthrax on face. Image courtesy of the Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Skin lesions of anthrax on neck. Cutaneous anthrax showing the typical black eschar. Image courtesy of the Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Histopathology of large intestine showing marked hemorrhage in the mucosa and submucosa. Image courtesy of Marshall Fox, MD, Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Histopathology of the large intestine showing submucosal thrombosis and edema. Image courtesy of Marshall Fox, MD, Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Inhalation anthrax. Chest radiograph with widened mediastinum 22 hours before death. Image courtesy of P.S. Brachman, MD, Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Histopathology of mediastinal lymph node showing mediastinal necrosis. Image courtesy of Marshall Fox, MD, Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Hemorrhagic meningitis resulting from inhalation anthrax. Image courtesy of the Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Anthrax infection. Histopathology of hemorrhagic meningitis in anthrax. Image courtesy of Marshall Fox, MD, Public Health Image Library, US Centers for Disease Control and Prevention, Atlanta, Georgia.

Microscopic picture of anthrax showing gram-positive rods. Image courtesy of Ramon E. Moncada, MD.

Bioterrorist Agents. Signs and symptoms. Chart courtesy of North Carolina Statewide Program for Infection Control and Epidemiology (SPICE), copyright University of North Carolina at Chapel Hill, www.unc.edu/depts/spice/bioterrorism.html.

Seven-month-old infant with anthrax. In this infant, the infection progressed rapidly with significant edema developing the day after exposure. This large hemorrhagic lesion developed within 3 more days. The infant was febrile and was admitted to the hospital on the second day after the symptoms appeared.On September 28, 2001, the infant had visited the mother's workplace. On September 29, nontender massive edema and a weeping erosion developed. On September 30, a 2-cm sore developed over the edematous area. (Note that edema preceded the primary lesion.) On October 2, an ulcer or eschar formed, and the lesion was diagnosed as a spider bite. Hemolytic anemia and thrombocytopenia developed, and the patient was hospitalized. Serum was drawn on October 2; the polymerase chain reaction results were positive for Bacillus anthracis. On October 13, skin biopsy results were positive with immunohistochemical testing for the cell wall antigen.Note that the initial working diagnosis was a Loxosceles reclusa spider bite with superimposed cellulitis. Courtesy of American Academy of Dermatology with permission of NEJM.

Fourth patient with cutaneous anthrax in New York City, October 2001. This dry ulcer was present. Photo used with permission of the patient. Courtesy of American Academy of Dermatology. Courtesy of Sharon Balter of the New York City Department of Health.

Note the hemorrhage that is associated with cutaneous anthrax lesions. The early ulcer has a moist base. Courtesy of American Academy of Dermatology.

Note the central ulcer and eschar. Courtesy of American Academy of Dermatology.

An example of a central ulcer and eschar with surrounding edema. Courtesy of American Academy of Dermatology with permission from Boni Elewski, MD.

Note the black eschar. Courtesy of American Academy of Dermatology. Courtesy of Gorgas Course in Clinical Tropical Medicine.

Anthrax with facial edema. Courtesy of American Academy of Dermatology.

Table 1. Microbiological Differences Between B anthracis and Non– B anthracis Bacilli

B anthracis	Non–B anthracis bacilli (pseudoanthrax bacilli)
Nonmotile long chains	Generally motile short chains
Capsule formation on bicarbonate agar	No capsule formation in bicarbonate
No growth on penicillin agar (10 mcg/mL)	Usually good growth on penicillin agar
Growth in gelatin resembles inverted fir tree	Growth in gelatin absent or resembles atypical fir tree
Gelatin liquefaction slow	Gelatin liquefaction usually rapid
No hemolysis of sheep RBCs	Hemolysis of sheep RBCs
Ferments salicin slowly or not at all	Usually ferments salicin rapidly
Pathogenic to laboratory animals	Nonpathogenic to laboratory animals
Adapted from Cunha CB. Anthrax: Ancient Plague, Persistent Problem. Infect Dis Pract. 1999;23(4):35-9.

Table 2. Toxins and Protein Toxins of Bacillus anthracis

Edema factor (EF) + lethal factor (LF) = Host cell penetration by B anthracis
EF + protective antigen (PA) = Edema toxin
LF + PA = Lethal toxin (primary virulence factor of B anthracis)
Edema toxin + lethal toxin = Inhibited PMN function and phagocytosis

Edema factor (EF) + lethal factor (LF) = Host cell penetration by B anthracis

EF + protective antigen (PA) = Edema toxin

LF + PA = Lethal toxin (primary virulence factor of B anthracis)

Edema toxin + lethal toxin = Inhibited PMN function and phagocytosis

View Table List