Blood Transfusion Infections

You shouldn't get an infection from a blood transfusion.

In the US, blood donors and their blood are rigorously screened to prevent transmission of infections.

Nothing is perfect, but the risks are low. New infections, rare infections may pass thought—or the lab just isn't perfect.

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There's a lot of blood given in the US each year. 9.5 million donate blood. That's about 1 in 33 Americans each year. 5 million receive over 14 million transfusions a year.

Around the world, not all blood is tested as well we might want. According to the WHO, in 2012, 39 countries are not testing all donations routinely for the most important infections (HIV, Hep B, Hep C, syphilis) and almost half of donations in low-income countries are tested in labs with quality assurance, meaning there was testing to ensure the lab results are expected to be accurate. 

What Infections Are Tested For?

In the US the following infections are tested for with the following exams:

  • Bacteria: Bacterial Culture
  • Hepatitis B: Hep B surface antigen and core antibody
  • Hepatitis C: Hep C antibody and nucleic acid amplification test (NAT)
  • HIV: HIV-1 and HIV-2 antibody and Nucleic acid amplification (NAT) for HIV-1
  • HTLV: HTLV-I and HTLV-II antibody
  • Syphilis: Anti-treponemal (syphilis) antibody detection
  • West Nile Virus: NAT for West Nile Virus

Blood is tested for Chagas through Trypanosoma cruzi antibody testing. For some CMV-negative patients (immunocompromised or transplant patients) blood is tested for CMV.

Babesia, a parasite normally tickborne, is one of the most common infections to pass through detection in the US as testing is not common. It can be easily treatable when diagnosed and infections are often mild. Some cases, representing a very small number of transfusions, have occurred and it is the most common reported cause of the very rare deaths associated with infections from transfusions.

What Donors Are Restricted?

There are many screening questions to avoid donors at risk for an infection that blood tests might miss.

In the United States, donors have to wait to give blood if they have a fever, are on antibiotics or treatment for TB, recently had a live vaccine (MMR - Measles, Mumps, Rubella, Chickenpox, Shingles, Yellow Fever, Polio, Hepatitis B, Smallpox). Those who have been detained or incarcerated in a jail, prison, juvenile detention for 72 hours must wait 1 year to donate.

You will need to wait if, in the last year, you have had gonorrhea or syphilis, a transfusion, or a tattoo in one of the many states that do not regulate tattoo use.

Blood is not tested for malaria. You'll need to wait three years if you've been treated for malaria or lived five years or so in an area with malaria. You'll need to wait 1 year if you've been to an area with malaria.

There have also been restrictions on men who have had sex with men; these men are not permitted by the FDA guidelines to donate blood if they have had sex with a man in the last year.

You cannot give blood if you've ever used IV drugs outside of a doctor's prescription, have worked in commercial sex work, or have had a partner in any of these high-risk groups for HIV.

To avoid CJD, donors are not allowed to have taken bovine insulin or a blood transfusion from the UK. You cannot donate blood if you lived in the UK from 1980-1996 for 3 months cannot donate, if they lived on particular US military bases in Europe for 6 months, or in Europe since 1980 for 5 years.

There are limits on how frequently someone may donate blood. Whole blood donation every 56 days, platelets every seven days (up to 24 times a year), plasma every 28 days (up to 13 times a year).

What Is the Risk?

The risk of HIV is about 1 in 2 million. 

The risk of Hepatitis B is about 1 in 200,000 (Get vaccinated!)

The risk of Hepatitis C is about 1 in 2 million.

There has always been a concern that Variant Creutzfeldt-Jakob disease (vCJD), or Mad Cow Disease, will spread via blood. This has never been seen, but to be careful, those who might have been exposed (who lived in areas where Mad Cow Disease was spreading in animals) are not permitted to donate blood.

Is It an Infection If I Feel Sick as I Am Getting the Blood?

Actually, there are many reactions to the blood that are not related to infections. These may seem like infections but your immune system is reacting to the new blood, not to any bacteria, virus, parasite, or other pathogens.

Many have allergic reactions to blood or to any components in blood, including medications or foods (such as even potentially peanuts eaten by a donor).

These allergic side effects include

  • fever
  • chills
  • clammy skin
  • nausea
  • rapid heartbeat, low blood pressure
  • trouble breathing
  • feeling anxious
  • chest or back pain

This can be mild. This can also be serious. Be sure to tell your nurse or doctor immediately if you have these symptoms. Reactions can be managed by health professionals.

There are other reactions as well. There can be reactions to the blood, especially if the blood matching was imperfect. These can result in the body destroying the blood cells, causing hemolysis or the popping of red blood cells. These can be acute (Acute Hemolytic Transfusion Reaction) or delayed (Delayed Hemolytic Transfusion Reaction or Delayed serologic transfusion reaction). There can also be lung injuries (Transfusion-related acute lung injury) and a variety of other reactions.

Have There Been Infections?

Huge advances have been made, and risks are extraordinarily low, the risk of infection from a blood transfusion still exists. The first case of HIV transmitted through blood was recognized in 1982. By 2001, it is thought, 14,262 persons have had AIDS as a result of a blood transfusion. Some countries delayed testing even longer - testing was incomplete in Japan and Germany well after other countries began maintaining an HIV-free blood system.

No one has ever been found to have HIV-2 from a blood transfusion in the United States. Blood is only tested for antibodies, not for the virus itself because the infection is so rare in the US. Only four blood donors have ever been found to have HIV-2 as of 1998.

There have also been cases of West Nile Virus (first reported in 2002) and Chagas transmitted by blood transfusion in the past.

Finally, new pathogens such as Babesia and COVID-19 bring up new challenges and new advances in safe blood banking.

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Article Sources
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Additional Reading
  • Wendel S. Transfusion-transmitted Chagas' disease. Curr Opin Hematol.1998 Nov;5(6):406-11.