Anthrax Infection Diagnosis and Testing

How anthrax is diagnosed

Doctors in the United States rarely see a patient with anthrax. CDC guidance and case definitions are available to help doctors diagnose anthrax, take patient histories to determine how exposure may have occurred, and order necessary diagnostic tests.

If inhalation anthrax is suspected, chest X-rays or CT scans can confirm if the patient has mediastinal widening or pleural effusion, which are X-ray findings typically seen in patients with inhalation anthrax.

The only ways to confirm an anthrax diagnosis are:

  • To measure antibodies or toxin in blood
  • To test directly for Bacillus anthracis in a sample
    • blood
    • skin lesion swab
    • spinal fluid
    • respiratory secretions

Samples must be taken before the patient begins taking antibiotics for treatment.

Laboratory testing for anthrax

Each half of the Petri dish culture plate was inoculated with the bacterium, Bacillus anthracis.

Laboratory systems are set up in the United States to quickly confirm or rule out whether a patient has anthrax or whether the environment is contaminated with Bacillus anthracis, the type of bacteria that causes anthrax. These labs are vital to the early identification of anthrax, especially in the case of a bioterrorism attack using anthrax.

However, the labs at CDC are always hard at work, not just during a bioterrorism event. They are working every day to conduct research that enhances the scientific understanding of anthrax. Laboratory scientists at CDC routinely strive to provide accurate information and efficient testing.

Labs at CDC work to:

  • Study and describe Bacillus anthracis
  • Provide anthrax reference diagnostics
  • Create new tests (including assays and diagnostics) to quickly identify anthrax
  • Test prevention and treatment options for anthrax
  • Provide epidemiological support and training to other labs and partners

All research with Bacillus anthracis is conducted in laboratories with the appropriate degree of containment to ensure public safety. The design of the secure laboratory facilities protects both scientists and the surrounding environment.

Laboratory Response Network (LRN)

Laboratory testing plays the largest role in diagnosing patients with anthrax. That’s why the Laboratory Response Network (LRN) would be essential to help hospitals, doctors, and public health officials quickly confirm a diagnosis of anthrax.

Public health scientist setting up a molecular test called a polymerase chain reaction (PCR).

The LRN was created through a partnership with the Department of Health and Human Services and the Centers for Disease Control and Prevention (CDC), the Federal Bureau of Investigation (FBI), and the Association of Public Health Laboratories (APHL). This network links state and local public health laboratories in all states with clinical, military, veterinary, and agricultural labs as well as labs that test water and food. Together, these labs can quickly identify biological threats, including anthrax.

Laboratories that are a part of the LRN can test patient specimens for Bacillus anthracis, the type of bacteria that causes anthrax. LRN labs are strategically located across the United States and abroad, each playing a role in their state’s or territory’s overall emergency response plan. If anthrax was intentionally released, quietly and without anyone knowing, it might be difficult for hospitals, doctors, and public health officials to diagnose anthrax in the first few patients. That’s why the Laboratory Response Network (LRN) would be essential during an anthrax emergency. Its purpose is to help hospitals, doctors, and public health officials quickly confirm a diagnosis of anthrax.

Additional Information