Hemovigilance Module FAQs

Hemovigilance Module Basics

What is the Hemovigilance Module of NHSN?

The Hemovigilance Module in the Biovigilance Component of NHSN is used to collect data about transfusion-related adverse events. The module is comprised of several data collection forms including the Annual Facility Survey, Adverse Reaction Form, Transfusions-Transmitted Infection Rapid Alert, and Transfusion-Transmitted Infection Investigation Form. The data collected in the Hemovigilance Module ranges from demographic information about your facility to total number of transfused units and adverse reactions that are used to calculate adverse event rates.

Who can participate in the Hemovigilance Module?

Enrollment in the Hemovigilance Module is open to all types of U.S. healthcare facilities where patients receive transfusions. Facility types include children’s hospitals, critical access hospitals, general hospitals (including acute, trauma, and teaching), long-term acute care hospitals, oncology hospitals, orthopedic hospitals, surgical hospitals, VA hospitals, women’s hospitals, and women’s and children’s hospitals.

Does participation in the Hemovigilance Module cost anything?

The Hemovigilance Module data reported to CDC will be used for public health purposes only. A facility is not required to report Hemovigilance Module participation to any agency, unless required to by state law. Reporting hemovigilance data to CDC does not replace the mandatory or regulatory reporting requirements of FDA, your state, or any other agency to which you may be required to report.

Does a facility have to report to CDC, FDA, and the state regulatory authority, if they are participating in NHSN?

The NHSN Hemovigilance Module data reported to CDC will be used for public health purposes only. A facility is not required to report Hemovigilance Module participation to any agency, unless required to by state law. Reporting hemovigilance data to CDC does not replace the mandatory or regulatory reporting requirements of FDA, your state, or any other agency to which you may be required to report.

How does a facility benefit from participating in the Hemovigilance Module?

Participants can use the data they enter into NHSN to systematically track the safety of transfusions, monitoring adverse reactions that occur in their facilities. Once sufficient data is reported for CDC to publish aggregate surveillance data, facilities will be able to compare their adverse event rates to aggregate data from facilities of similar size and characteristics. Facility data also enables CDC to provide nationwide estimates of serious adverse reactions and can help provide an early warning system for emerging pathogens.

Who has ownership of the Hemovigilance Module data and who has access to the Hemovigilance Module data?

Each facility owns the data they enter into the Hemovigilance Module. As a requirement of participation in NHSN, facilities agree to share this data with CDC for public health surveillance purposes. In addition, facilities may choose to share their data with entities that have formed Groups in NHSN via conferred rights or data use agreement. CDC will not share facility Hemovigilance Module data with any outside entity.  In the event of a public health concern (TTI), your local/state health department and federal partners (FDA) may be notified.

How does a facility ask questions about the Hemovigilance Module?

CDC is available to answer questions about the Hemovigilance Module Protocol and to help navigate the NHSN web application. For hemovigilance-specific questions, please contact hemovigilance@cdc.gov. For questions or issues related to the NHSN web application, please contact nhsn@cdc.gov. Emails are monitored regularly during business hours Monday-Friday, and facilities should expect a response within one or two business days.

Hemovigilance Module Enrollment and Trainings

How does a facility get started in the Hemovigilance Module?

Before beginning the NHSN enrollment process, the facility must determine whether or not they are already enrolled in NHSN for another reporting purpose. If the facility is not enrolled in NHSN, the facility will need to begin the NHSN enrollment process. If the facility is enrolled in NHSN, the NHSN Facility Administrator will activate the Biovigilance Component and add users for the Biovigilance Component. Activating the Biovigilance Component enrolls your facility into the Hemovigilance Module.

How does a facility determine whether or not they are already enrolled in NHSN?

The interested user should contact the infection prevention team or hospital epidemiologist at their facility. Because participation in NHSN is confidential, CDC is unable to publish a list of enrolled facilities. If you are unable to determine whether or not your facility is enrolled in NHSN, contact the NHSN User Support team at CDC (nhsn@cdc.gov).

What training is available for participation in the Hemovigilance Module?

Facility users can review the Hemovigilance Module Protocol, data collection forms, and their accompanying instructions. Training resources for the Hemovigilance Module are available on the Biovigilance Component Training webpage.

Hemovigilance Reporting Guidelines

What is reported into the Hemovigilance Module?

Participating facilities can submit an annual facility survey and transfusion-related adverse reactions (AHTR, TACO, TRALI, TTI, other) identified at their facility into the module. All facilities should use the CDC standardized case definitions, imputability, and severity classifications when reporting adverse reactions to the module.

How often are adverse reactions reported?

According to the 2023 National Blood Collection and Utilization Survey (NBCUS), transfusion-associated circulatory overload (TACO) occurred at a rate of 19.3 per 100,000 components transfused, transfusion-related acute-lung injury (TRALI) occurred at a rate of 1.0 per 100,000 components transfused, acute hemolytic transfusion reaction (AHTR) (ABO) occurred at a rate of 0.46 per 100,000 components transfused, and AHTR (other antibodies) occurred at a rate of 1.2 per 100,000 components transfused. Transfusion-transmitted bacterial infection (previously asked as posttransfusion sepsis) occurred at a rate 0.24 per 100,000 components, but no transfusion-transmitted viral infections or parasitic infection were reported by transfusing facilities sampled during the 2023 NBCUS cycle. Of note, adverse reactions reported to the 2023 NBCUS were not required to have met the NHSN Biovigilance Component – Hemovigilance Module case definitions or imputability criteria.¹

What if a facility’s adverse reaction definitions aren’t exactly the same as those defined in the Hemovigilance Module?

All facilities should use the CDC standardized case definitions, imputability, and severity classifications when reporting adverse reactions to the module.

How should the location of an adverse event be determined, and what is a CDC location?

The location for the adverse event is the patient care area to which a patient is assigned while receiving care in the healthcare facility. A CDC location is a CDC-defined designation given to a patient care area housing patients who have similar disease conditions or who are receiving care for similar medical or surgical specialties. Each facility location that is monitored is “mapped” to one CDC Location. The specific CDC Location code is determined by the type of patients cared for in that area according to the 80% Rule. That is, if 80% of patients are of a certain type (e.g., pediatric patients with orthopedic problems) then that area is designated as that type of location (in this case, an Inpatient Pediatric Orthopedic Ward). The admission/transfer diagnosis should be used when determining the appropriate location mapping. The admission diagnosis is considered the most accurate depiction of the patient’s illness and reason for being admitted to a particular unit. (See also virtual location in the Locations and Descriptions chapter.)

For detailed instructions on how to map locations, see “Instructions for Mapping Patient Care Locations in NHSN” in the Locations and Descriptions chapter [PDF – 1 MB].