Volume 8, Number 10—October 2002
THEME ISSUE
Bioterrorism-related Anthrax
Bioterrorism-related Anthrax
Specific, Sensitive, and Quantitative Enzyme-Linked Immunosorbent Assay for Human Immunoglobulin G Antibodies to Anthrax Toxin Protective Antigen
Table
Serum test group | AVA vaccinees | Non-Vaccinees | NHANES controls | Non-anthrax infections | Clinical anthrax serab | Total sera of known infection and vaccination status |
---|---|---|---|---|---|---|
True positivesc | 67 | 0 | 0 | 0 | 15 | 87 |
True negativesd | 0 | 15 | 228 | 260 | 0 | 503 |
False positivese | 0 | 4 | 10 | 17 | 0 | 31 |
False negativesf | 1 | 0 | 0 | 0 | 1 | 2 |
Total | 68 | 19 | 238 | 277 | 16 | 618 |
Diagnostic specificity | n/a | 78.9% | 95.7% | 93.8% | n/a | 94.2% |
Diagnostic sensitivity | 98.5% | n/a | n/a | n/a | 93.7% | 97.6% |
aAVA, anthrax vaccine adsorbed; NHANES, National Health and Nutrition Examination Survey; n/a, not applicable.
bClinical anthrax sera were obtained from donors that met the Centers for Disease Control and Prevention case definition for confirmed cutaneous and inhalational anthrax. Patients were classified as either reactive or nonreactive.
cSera are considered true positives if they were obtained from clinically confirmed anthrax cases or from donors with a documented history of anthrax vaccination.
dTrue-negative sera were selected on the basis of having no known exposure to Bacillus anthracis infection and no known anthrax vaccination.
eFalse-positive sera are defined as sera which reacted (>3.0 µg/mL) in the anti-protective antigen immunoglobulin G enzyme-linked immunosorbent assay but for which there is no history of clinical anthrax or anthrax vaccination.
fFalse-negative sera are defined as sera from donors who are documented as vaccine recipients or had clinically confirmed anthrax.