Sandbox JA

Medical Therapy

The treatment of anthrax infection includes antimicrobial and antitoxin agents. This treatment and postexposure prophylaxis differs from other bacterial infections because:

• Production of toxin
• Potential antibiotic resistance
• Frequent occurrence of meningitis
• Presence of latent spores must be taken into account when selecting postexposure prophylaxis or a combination of antibiotics for treatment of anthrax.

Hospitalized patients for systemic anthrax should be immediately treated with a combination of broad-spectrum intravenous antimicrobial drug treatment pending confirmatory test results because any delay may prove fatal.

Because meningitis and hemorrhagic brain parenchymal infection was observed in ≤50% of cases, meningitis must be considered in all cases of systemic anthrax. Therefore antibiotics to treat possible meningitis must have good penetration of the central nervous system (CNS).

Because of the presence of a spore form of Bacillus anthracis, antibiotic therapy should be continued for 60 days to clear germinating organisms

Antimicrobial Treatment

Follow–up Oral Treatment for Systemic Disease

Once patients with systemic illness who were exposed to aerosolized spores have completed initial combination treatment, they should be transitioned to single-agent oral treatment to prevent relapse from surviving Bacillus anthracis spores.

Antitoxins

An antitoxin should be added to combination antibiotic treatment for any patient for whom there is a high level of clinical suspicion for systemic anthrax. Given that systemic anthrax has a high case-fatality rate and the risk for antitoxin treatment appears to be low, the potential benefit achieved by adding antitoxin to combination antibiotic treatment outweighs the potential risk.

Currently there are 2 antitoxins in the CDC Strategic National Stockpile: raxibacumab and Anthrax Immune Globulin Intravenous (AIGIV). Both antitoxins inhibit binding of PA to anthrax toxin receptors and translocation of the 2 primary toxins (LT and ET) into cells. Raxibacumab is a recombinant, fully humanized, IgG1λ monoclonal antibody. AIGIV is a human polyclonal antiserum made from plasma of persons immunized with AVA, which might have some direct effect on LF and EF.