Babesiosis Overview

Babesiosis is a “tick-borne zoonosis caused by infections with intra-erythrocytic protozoa of the genus Babesia” that can be transmitted from an infected donor through transfusion of blood products and solid organ transplantation:

  • Transfusion-transmission is reported year-round. The highest prevalence is reported in the United States with the majority of cases caused by B. microti (prevalent in the Northeast and upper Midwest). Other Babesia species and related organisms are implicated in transmission of Babesia in several western US states.
  • The vast majority of B. microti infections are asymptomatic and never diagnosed.
  • The parasitemic period for B. microti is reported to last from 2 to 7 months but may persist for more than 2 years.
  • Transfusion of blood products collected from asymptomatic donors may result in transmission of the infection and potentially fatal clinical illness in blood transfusion recipients.

Regulatory Considerations

The recommendations of Food and Drug Administration’s (FDA) May 2019 Babesia Guidance consider babesiosis to be a relevant transfusion-transmitted infection under 21 CFR 630.3(h)(2), and call for regional testing or pathogen reduction in the 15 identified Babesia-risk states. In states where testing is not required, FDA is recommending donor centers revise their Donor History Questionnaire to ask prospective donors if they have “ever had a positive test result for Babesia.” The following tools are publicly available:

AABB Exclusive Member Offering: Babesia Toolkit NEW

In addition to the Highlights and tools linked above that are publicly available, AABB Regulatory Affairs has condensed the May 2019 recommendations into 5 operational flowcharts to assist members*:

  • Testing: Options for use in states where testing is required.
  • PRT: Alternative options in states where testing or PRT is required.
  • Testing/PRT is performed with use of revised Question 38.
  • Revised Question 38 in states where testing is not required.
  • Product Management, donor notification and counseling.

*AABB’s Weekly Report, available to all AABB members, announces exclusive member offerings that are available to AABB individual members and the accreditation contact for AABB accredited facilities.

NOTE: Issue of the May 2019 Babesia Guidance rendered portions of the AABB Association Bulletin #14-05 obsolete. However, sections on “Information for Clinicians” and “Managing Potential Transfusion-Transmitted Babesiosis Cases” continue to remain relevant.

AABB works closely with the FDA, Centers for Disease Control and Prevention, and the Council of State and Territorial Epidemiologists to assess the latest scientific information and develop appropriate tools and policies to reduce the risk of transfusion-transmitted B. microti infection.

Recent Actions

AABB released a Babesia Toolkit that helps transfusion donor services better understand and implement FDA’s May 2019 Babesia Guidance. The toolkit’s detailed flowcharts represent acceptable pathways through implementation of testing, pathogen reduction, donor screening, deferral, product management and consignee notification.

The FDA has issued a guidance, Recommendations for Reducing the Risk of Transfusion-Transmitted Babesiosis, finalizing the draft guidance of the same title dated July 2018.

AABB, America's Blood Centers (ABC) and the American Red Cross (ARC) provided joint comments to the Food and Drug Administration’s July 2018 draft guidance, Recommendations for Reducing the Risk of Transfusion-Transmitted Babesiosis.

The Food and Drug Administration issued a draft guidance, Recommendations for Reducing the Risk of Transfusion-Transmitted Babesiosis, which classifies babesiosis as a relevant transfusion-transmitted infection under 21 CFR 630.3(h)(2). Draft recommendations include donor screening, donation testing, donor deferral, labeling and product management to reduce the risk of transfusion-transmitted babesiosis.