Clinical Features of Patients Hospitalized for All Routes of Anthrax, 1880-2018: A Systematic Review

Background Anthrax is a toxin-mediated zoonotic disease caused by Bacillus anthracis, with a worldwide distribution recognized for millennia. Bacillus anthracis is considered a potential biowarfare agent. Methods We completed a systematic review for clinical and demographic characteristics of adults and children hospitalized with anthrax (cutaneous, inhalation, ingestion, injection [from contaminated heroin], primary meningitis) abstracted from published case reports, case series, and line lists in English from 1880 through 2018, assessing treatment impact by type and severity of disease. We analyzed geographic distribution, route of infection, exposure to anthrax, and incubation period. Results Data on 764 adults and 167 children were reviewed. Most cases reported for 1880 through 1915 were from Europe; those for 1916 through 1950 were from North America; and from 1951 on, cases were from Asia. Cutaneous was the most common form of anthrax for all populations. Since 1960, adult anthrax mortality has ranged from 31% for cutaneous to 90% for primary meningitis. Median incubation periods ranged from 1 day (interquartile range [IQR], 0-4) for injection to 7 days (IQR, 4-9) for inhalation anthrax. Most patients with inhalation anthrax developed pleural effusions and more than half with ingestion anthrax developed ascites. Treatment and critical care advances have improved survival for those with systemic symptoms, from approximately 30% in those untreated to approximately 70% in those receiving antimicrobials or antiserum/antitoxin. Conclusions This review provides an improved evidence base for both clinical care of individual anthrax patients and public health planning for wide-area aerosol releases of B. anthracis spores. In this systematic review, we summarize the following information for adults and children hospitalized for each route of anthrax for approximately 140 years: signs, symptoms, laboratory results, complications, outcomes, type of exposure, incubation period, and length of stay.

Automated summary

This systematic review examined the clinical and demographic characteristics of adults and children hospitalized with anthrax from 1880 to 2018, finding cutaneous anthrax to be the most common form. Since 1960, adult anthrax mortality has ranged from 31% for cutaneous to 90% for primary meningitis, and advances in treatment and critical care have improved survival rates for patients.