Methods: A systematic review of 12 databases from inception through May 14, 2014 identified reports describing treatment for systemic anthrax. We then selected complicated cutaneous anthrax cases (with SIRS criteria or evidence of meningitis), receiving ≥ 1 antibiotic from CDC’s anthrax treatment guidance, for whom outcome was recorded. Associations of death with age, sex, presence of SIRS, presence of meningitis, and overlapping bactericidal-protein synthesis inhibitor therapy (combination therapy) were determined. A multivariate model was created using covariates with p ≤ 0.1. Sub-analysis of non-meningitis cases was performed.
Results: Of 149 systemic anthrax cases, 59 had complicated cutaneous disease. Thirty-nine of 57 with age data were ≥18 years; 40/57 with sex data were male. For 33/59 evidence of meningitis was presented. Fever, leukocytosis, tachypnea, tachycardia and hypotension were reported in: 24, 20, 16, 7, and 7 cases, respectively. Twenty-six died, of which 25 had meningitis. Adults (OR 6.5, p 0.009), males (OR 3.6, p = 0.05), meningitis (OR 78, p < 0.0001) and combination therapy (OR 4.65, p = 0.08) were associated with death; leukocytosis was inversely associated (OR 0.29, p = 0.04). Only meningitis remained significant in multivariate analysis (aOR 21, p = 0.01). For 26 cases without meningitis, combination therapy was not associated with survival (24/25 and 1/1 survived without and with combination therapy, respectively, Fischer’s exact p = 1).
Conclusion: Mortality is high for cutaneous anthrax complicated by meningitis. Cutaneous anthrax complicated by evidence of systemic infection but without meningitis appears to have better outcomes and in such cases monotherapy may be appropriate, particularly in a mass casualty anthrax incident if antibiotic shortages necessitate adjustment to current treatment guidance.
K. Hendricks, None
W. Bower, None
D. Meaney-Delman, None