Anthrax Case Definition, Reporting, and Surveillance

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.

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 a reportable condition 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

Anthrax has been a nationally notifiable condition since 1944. 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.
• What to do:
  • The jurisdictional health department should call the CDC Emergency Operations Center (EOC) at (770)-488-7100 within 4 hours of the notification criteria being met.
• Upon receiving notification, a CDC subject matter expert will call back within 1 hour and will 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).
• Changes in a patient's case classification (for example, from suspect to confirmed) should be submitted by the next business day after the change occurs.

Immediate, Urgent: Notification within 24 hours

• Notification criteria:
  • A case of naturally occurring or occupational-related anthrax that is responding to treatment.
• What to do:
  • The jurisdictional health department should call the CDC EOC within 24 hours of knowing the notification criteria are met.
• A CDC subject matter expert will call back within 4 hours 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.
• Changes in a patient's case classification (for example, from suspect to confirmed) should be submitted by the next regularly scheduled transmission cycle after the change occurs.

Following initial notification

• To report subsequent epidemiologically linked cases, the jurisdictional health department should directly notify the CDC staff member who responded to the initial notification instead of contacting the CDC EOC.
• If a patient is determined to meet case classification criteria during a discussion with CDC, additional notification to the CDC EOC is not needed.

Laboratory notification

Bacillus anthracis is designated as a Tier 1 select agent by the CDC-USDA Select Agent Program. 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 DCIPHER through Secure Access Management Services (SAMS) credentialing. To request DCIPHER access, for more information about the system, or for other surveillance-related questions, health departments can 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.