Blood Safety Basics

Key points

  • Each day, life-saving blood transfusions are needed across the United States.
  • Most patients do not experience side effects from transfusions. On rare occasions, transfusions can cause adverse reactions in patients receiving blood.
  • Although the U.S. blood supply is safer than ever, some bacteria, viruses, etc. can infect blood transfusion recipients.
  • All blood donors and blood donations are screened for infections and diseases.


The U.S. blood supply is safer than it has ever been. However, blood transfusions can transmit any bloodborne pathogen.

Report a Possible Outbreak

To report a possible transfusion-transmitted infection cluster or outbreak.

Call: 770-488-7100


Several types of bacteria, viruses, parasites and prions can infect blood donors and recipients, though these infections are rare. Adverse reactions (e.g., allergic reaction, transfusion-transmitted infection, etc.) to a blood transfusion are also very rare. The most common adverse reactions from blood transfusions are allergic and febrile reactions, which make up over half of all adverse reactions reported.

Reducing Risk

Screening donated blood

Healthcare providers and blood banks ask donors a set of standard questions before donating blood including:

  • Whether or not they are in good health
  • Their social behavior and health history
  • If they are free of any bacterial, viral or parasitic diseases
  • If they have traveled to areas where transmittable diseases are common

If their answers indicate they are not well or are at risk for having a disease transmissible by blood transfusion, they cannot donate blood.

Testing donated blood

Once donated, laboratory technicians test for blood type, certain infectious diseases and additional proteins (or antibodies) that may cause adverse reactions in a person receiving a blood transfusion.

Quick Facts

  • There are approximately 7 million blood donors and more than 14 million units of blood transfused annually in the United States.
  • Every 2 seconds someone in the United States needs blood and or platelets.
  • The U.S. healthcare system needs approximately 29,000 units of red blood cells every day.
  • The U.S. healthcare system needs nearly 5,000 units of platelets and 6.500 units of plasma per day.

What CDC is doing

  • The CDC's Office of Blood, Organ and Other Tissue Safety (BOOTS) conducts surveillance for adverse events following blood transfusions. Providers can use this information to prevent transfusion-related events through evidence-based interventions and recommendations. Hospitals provide this information voluntarily.
  • Assisting state and local health departments and hospitals in investigating reports of potential infectious disease transmission.
  • Collecting and monitoring data on blood safety and adverse reactions in the National Healthcare Safety Network (NHSN) Hemovigilance Module since 2010. By collecting data in a national system, CDC analyzes aggregate data to understand how to prevent transfusion-related adverse events.
  • Conducting surveillance for blood utilization through the National Blood Collection & Utilization Survey.

Other federal agencies involved in blood safety



  • Hong, H., Xiao, W., Lazarus, H. M., Good, C. E., Maitta, R. W., & Jacobs, M. R. (2016). Detection of septic transfusion reactions to platelet transfusions by active and passive surveillance. Blood, 127(4), 496-502. Accessed November 04, 2018.
  • Levy JH, Neal MD, Herman JH. Bacterial contamination of platelets for transfusion: strategies for prevention. Crit Care. 2018 Oct 27;22(1):271. doi: 10.1186/s13054-018-2212-9. PMID: 30367640; PMCID: PMC6204059.
  • McFee RB. Tick borne illness – Anaplasmosis. Dis Mon. 2018 May;64(5):181-184. doi: 10.1016/j.disamonth.2018.01.005. Epub 2018 Mar 1. PMID: 29503011.
  • Regan J, Matthias J, Green-Murphy A, Stanek D, Bertholf M, Pritt BS, Sloan LM, Kelly AJ, Singleton J, McQuiston JH, Hocevar SN, Whittle J. A Confirmed Ehrlichia ewingii Infection Likely Acquired Through Platelet Transfusion, Clinical Infectious Diseases, Volume 56, Issue 12, 15 June 2013, Pages e105–107,
  • Shakir R. Brucellosis. J Neurol Sci. 2021 Jan 15;420:117280. doi: 10.1016/j.jns.2020.117280. Epub 2020 Dec 21. PMID: 33358192.


Biovigilance is a national patient safety program to gather, analyze and report data. The program focuses on outcomes related to the collection and transfusion and/or transplantation of blood components and derivatives, cells, tissues and organs. The publication Biovigilance in the United States: Efforts to Bridge a Critical Gap in Patient Safety and Donor Health summarizes biovigilance efforts in the United States.