Transfusion medicine

• Blood borne viruses, bacteria, parasites and, theoretically, prions may be transmitted by transfusion
• Screening and laboratory testing aims to exclude:
  • Viruses: a risk with all blood products
  • Bacteria: room temperature platelet products are highest risk (Centers for Disease Control and Prevention: Handling and Bacteriologic Work-up of Blood Components [Accessed 20 July 2021])
    • Common bacteria include skin flora (e.g. Staphylococcus epidermidis, Staphylococcus aureus)
    • Psychrophilic (cold tolerant) bacteria pose risk in refrigerated products (e.g. Yersinia enterocolitica)
    • Unlikely to survive in frozen, acellular products, such as plasma and cryoprecipitate
  • Parasites
    • Plasmodium spp. (malaria)
    • Babesia microti
  • Prions (U.S. Food and Drug Administration: Recommendations to Reduce the Possible Risk of Transmission of Creutzfeldt-Jakob Disease and Variant Creutzfeldt-Jakob Disease by Blood and Blood Components [Accessed 20 July 2021], Transfusion 2017;57:1875, Vox Sang 2016;110:310, Transfusion 2020;60:694)
    • Recent evidence that nonvariant Creutzfeld-Jakob Disease is not transfusion transmitted

Dear ### (Blood Donor Name),

In order to safeguard the blood supply, we perform a number of laboratory tests to make sure that potential donors do not have transfusion transmissible illnesses (TTI). This includes screening for various viruses and bacteria. Such testing is very sensitive but false positives may also occur. One of your tests warrants further investigation.

Please call the Blood Donor Center at (###) ###-#### between the hours of 8 a.m. to 4:30 p.m., Monday through Friday for more information.

Sincerely,

Medical Director of Transfusion Medicine

Reference: U.S. Food and Drug Administration: Guidance for Industry Donors of Blood and Blood Components: Notification of Donor Deferral Small Entity Compliance Guide [Accessed 20 July 2021]

A 20 year old man schedules an appointment to donate blood at a blood drive held on his university campus. He previously donated blood while he was a high school student. On his donor questionnaire, he notes that he recently started taking isotretinoin (Accutane) for acne. What is the blood donation deferral period for taking this medication?

1. 1 month after the last dose
2. 1 year after the last dose
3. 6 months after the last dose
4. Indefinite
5. No deferral

A. Isotretinoin (Accutane) use is a 1 month deferral after the last dose due to the potentially teratogenic effects, should the donated blood be transfused to a pregnant woman.

Comment here

Reference: Donor eligibility

A 35 year old woman presents to donate blood. Upon screening, she reveals that she was treated for Plasmodium vivax malaria after spending 3 months on a medical missions trip to Africa. Her treatment ended 6 months ago. How long should she be deferred from donating blood?

1. 3 months after treatment; she has been eligible to donate for 3 months
2. 3 years after treatment has ended and donor is symptom free
3. 6 months after treatment; she is eligible to donate now
4. 6 more months for a total of 1 year deferral after treatment
5. Indefinite deferral

B. Donors who have been diagnosed with malaria are deferred for a 3 year period after treatment and with the qualification that they are symptom free. Some forms of malaria may remain dormant in the liver and reactivate at a later time. Proper treatment is critical for preventing reactivation. A 3 year deferral takes the potential of reactivation into account. Individuals who have been successfully treated for the potential latent, liver phase of malaria are deferred for 3 years after completion of treatment. After this deferral period, provided there is no additional travel history or evidence of reinfection / reactivation of infection, these individuals are eligible for donation.

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Reference: Donor eligibility