Recommended Specimens for Anthrax Testing by Clinical Presentation
Specimen submission requirements for CDC Infectious Diseases Laboratories are being updated. Updates could affect the acceptable specimen types, storage conditions, shipping conditions, and documentation. Unfortunately, submissions not meeting the updated requirements cannot be accepted. For information on specific tests, click the relevant link below to the CDC Test Directory.
Test Name
Test Name
Test Code
Test Code
Bacillus anthracis detection in clinical specimens
Bacillus anthracis detection in clinical specimens
Bacillus anthracis genotyping and AST
Bacillus anthracis genotyping and AST
Recommended specimens by clinical presentation
Culturing B. anthracis from clinical specimens is the gold standard for diagnosing anthrax. If anthrax is suspected, clinical specimens, including blood cultures, should be collected before starting antimicrobial therapy. Culture will likely be negative if clinical specimens are collected after initiating antimicrobial therapy, regardless of the form of disease (cutaneous, gastrointestinal, inhalation, injection, or meningeal anthrax). However, other tests not requiring a viable organism may be positive after antimicrobial use, if collected as directed below.
Depending on the form of disease, organisms can be cultured from the following specimens:
- Blood
- Skin lesion exudates
- Pleural fluid
- Cerebrospinal fluid (CSF)
- Rectal swab
- Ascites fluid
- Tissues from biopsy or autopsy
Each section contains guidance for recommended biological specimens that may be submitted for anthrax diagnostic testing. Note: On a case-by-case basis, one or more clinical specimens may be recommended for submission, as available.
Specific packaging and shipping information by specimen and test type:
Cutaneous
Lesion Swabs
Lesion Swabs
Vesicular lesions: Two swabs of vesicular fluid from an unopened vesicle, one for culture and one for real-time polymerase chain reaction (PCR).
Eschars: Two saline-moistened swab samples, rotated underneath the eschar, one for culture and one for real-time PCR.
Ulcers: Sample the base of the lesion with two saline-moistened swabs, one for culture and one for real-time PCR.
Vesicular lesions: Two swabs of vesicular fluid from an unopened vesicle, one for culture and one for real-time polymerase chain reaction (PCR).
Eschars: Two saline-moistened swab samples, rotated underneath the eschar, one for culture and one for real-time PCR.
Ulcers: Sample the base of the lesion with two saline-moistened swabs, one for culture and one for real-time PCR.
Biopsy
Biopsy
A full thickness biopsy of a papule or vesicle, including adjacent skin, for histopathology, special stains, and immunohistochemistry (IHC).
Note: For patients who are not on antibiotic therapy or who have been on therapy for < 24 hours, a second biopsy sample should be collected at the same time and submitted for culture and real-time PCR.
A full thickness biopsy of a papule or vesicle, including adjacent skin, for histopathology, special stains, and immunohistochemistry (IHC).
Note: For patients who are not on antibiotic therapy or who have been on therapy for < 24 hours, a second biopsy sample should be collected at the same time and submitted for culture and real-time PCR.
Serum
Serum
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
Plasma
Plasma
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
Blood
Blood
If there are signs of systemic anthrax infection (i.e., febrile or hypothermia, tachycardia, tachypnea, hypotensive), collect blood specimen before starting antimicrobial therapy for culture and real-time PCR.
If there are signs of systemic anthrax infection (i.e., febrile or hypothermia, tachycardia, tachypnea, hypotensive), collect blood specimen before starting antimicrobial therapy for culture and real-time PCR.
CSF
CSF
To be submitted for patients with severe headache, meningeal signs, altered mental status, seizures, or focal signs for culture and real-time PCR.
To be submitted for patients with severe headache, meningeal signs, altered mental status, seizures, or focal signs for culture and real-time PCR.
Autopsy Tissues
Autopsy Tissues
To be collected in fatal cases for histopathology, special stains, and IHC.
To be collected in fatal cases for histopathology, special stains, and IHC.
Gastrointestinal
Oropharyngeal lesion swab, if present
Oropharyngeal lesion swab, if present
To be tested for culture and real-time PCR.
To be tested for culture and real-time PCR.
Serum
Serum
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
Plasma
Plasma
Acute plasma samples for testing of anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
Acute plasma samples for testing of anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
Blood
Blood
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
Ascites Fluid
Ascites Fluid
To be tested for culture, real-time PCR, and anthrax lethal factor toxin testing.
To be tested for culture, real-time PCR, and anthrax lethal factor toxin testing.
Rectal swab
Rectal swab
To be tested for culture and real-time PCR.
To be tested for culture and real-time PCR.
Autopsy Tissues
Autopsy Tissues
To be collected in fatal cases for histopathology, special stains, and IHC.
To be collected in fatal cases for histopathology, special stains, and IHC.
Inhalation
Serum
Serum
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
Plasma
Plasma
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
Blood
Blood
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
Pleural Fluid
Pleural Fluid
To be tested for culture and real-time PCR, as well as anthrax lethal factor toxin.
To be tested for culture and real-time PCR, as well as anthrax lethal factor toxin.
CSF
CSF
To be submitted for patients with severe headache, meningeal signs, altered mental status, seizures, or focal signs for culture and real-time PCR.
To be submitted for patients with severe headache, meningeal signs, altered mental status, seizures, or focal signs for culture and real-time PCR.
Biopsy
Biopsy
Pleural and/or bronchial biopsies for IHC.
Pleural and/or bronchial biopsies for IHC.
Autopsy Tissues
Autopsy Tissues
To be collected in fatal cases for histopathology, special stains, and IHC.
To be collected in fatal cases for histopathology, special stains, and IHC.
Injection
Serum
Serum
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
Plasma
Plasma
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
Blood
Blood
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
Biopsy
Biopsy
Tissue biopsy from localized lesion tissue debridement.
Tissue biopsy from localized lesion tissue debridement.
Autopsy Tissues
Autopsy Tissues
To be collected in fatal cases for histopathology, special stains, and IHC.
To be collected in fatal cases for histopathology, special stains, and IHC.
Meningeal
Meningitis can complicate cases of cutaneous, gastrointestinal, inhalation, and injection anthrax cases. Meningitis may also be the primary sign of anthrax in patients without a clear source of exposure. The following specimens should be submitted in patients with severe headaches, meningeal signs, altered mental status, seizures, or focal signs.
Serum
Serum
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
An acute (≤7 days after symptom onset OR as soon as possible after a known exposure event) serum sample to test for anthrax lethal factor toxin.
Acute and convalescent (14–35 days after symptom onset) serum samples for serologic testing.
Plasma
Plasma
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
An acute plasma sample to test for anthrax lethal factor toxin.
Note: Plasma is the preferred specimen for anthrax lethal factor toxin testing.
Blood
Blood
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
To be drawn before starting antimicrobial therapy for culture and real-time PCR.
CSF
CSF
To be tested for culture and real-time PCR.
To be tested for culture and real-time PCR.
Autopsy Tissues
Autopsy Tissues
To be collected in fatal cases for histopathology, special stains, and IHC.
To be collected in fatal cases for histopathology, special stains, and IHC.