Anthrax Case Definition, Reporting, and Surveillance

Key points

  • Anthrax in people is a nationally notifiable condition and is reportable in all states and territories.
  • CDC and health departments use a standardized case definition to track anthrax in the United States.
  • CDC publishes weekly and annual surveillance data in the Notifiable Infectious Disease Data Tables.

Case definition

The anthrax surveillance case definition provides a set of consistent criteria used to define the disease for public health surveillance and reporting. Surveillance case definitions enable public health officials to classify and count cases based on the same criteria across reporting jurisdictions. Surveillance case definitions are not intended for healthcare providers when making a clinical diagnosis or determining how to meet an individual patient's health needs.

Welder's anthrax

Welder's anthrax is a newly identified, rare disease that has been found in a small number of people who are welders or metalworkers. This disease causes severe pneumonia and can be fatal. The Council of State and Territorial Epidemiologists (CSTE) added welder's anthrax to an updated anthrax case definition in 2025.

Reporting criteria

National-level monitoring of notifiable conditions helps protect the health of the nation. Information from surveillance notifications shared by health departments can be used to better understand where and how much disease is occurring and what groups it's affecting, as well as determine the best strategies to prevent and respond to the illness.

Anthrax in people is nationally notifiable and reportable in all states and territories. Healthcare providers, hospitals, or laboratories must report anthrax cases to their local health departments. Specific requirements for who must report cases and when to report vary by jurisdiction.

Case notification

The Council of State and Territorial Epidemiologists (CSTE) designates anthrax in people as a nationally notifiable condition. If a patient meets probable or confirmed case criteria for anthrax, CSTE requests that health departments alert CDC in a timely manner depending on the criteria below.

Immediate, Extremely Urgent: Notification within 4 hours

Notification criteria

  • When the source of infection is not recognized or is recognized as a bioterrorism exposure/potential mass exposure OR
  • When the case represents a serious illness of naturally occurring anthrax

Process

  • The health department calls the CDC Emergency Operations Center (EOC) at 770-488-7100 within 4 hours of being informed that notification criteria are met.
  • Upon receiving notification, a CDC subject matter expert will call back within 1 hour and send written or email confirmation that the case notification was received.
  • Electronic transmission to the National Notifiable Diseases Surveillance System (NNDSS) should be done by the next business day. (See reporting methods below).
  • Submit changes in a patient's case classification (for example, from suspect to confirmed) by the next business day after the change occurs.

Immediate, Urgent: Notification within 24 hours

Notification criterion

  • A case of naturally occurring or occupational-related anthrax that is responding to treatment.

Process

  • The health department calls the CDC EOC at 770-488-7100 within 24 hours of being informed that notification criteria are met.
  • A CDC subject matter expert will call back within 1 hour and will send written or email confirmation that the case notification was received by CDC.
  • Electronic transmission to NNDSS should be done by the next regularly scheduled transmission cycle.
  • Submit changes in a patient's case classification (for example, from suspect to confirmed) by the next regularly scheduled transmission cycle after the change occurs.

Following initial notification

  • To report subsequent epidemiologically linked cases, the health department should directly notify the CDC staff member who responded to the initial notification rather than contact the CDC EOC.
  • No additional notification to the CDC EOC is needed if CDC staff determine a patient meets case classification criteria.

Laboratory notification

Bacillus anthracis is designated as a Tier 1 Select Agent. If an organism is identified as or suspicious for B. anthracis, contact your state or local public health department immediately.

Reporting methods

Health departments should report general information about the patient and disease to CDC through NNDSS using National Electronic Telecommunications System for Surveillance (NETSS) messages or the generic message mapping guide.

Health departments may also report anthrax to the CDC using the anthrax case report form that can be completed electronically. Completed forms can be securely emailed or faxed to CDC through the contacts listed on the form.

Jurisdictional health departments can directly report cases via 1CDP through Secure Access Management Services (SAMS) credentialing. To request 1CDP access, for more information about the system, or for other surveillance-related questions, contact CDC's Bacterial Special Pathogens Branch at bspb@cdc.gov.

CDC surveillance data

Weekly and annual surveillance data for anthrax cases in people are published in the NNDSS notifiable infectious disease data tables.

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Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID); About Division of High-Consequence Pathogens and Pathology