Diseases and Organisms

Bacterial contamination of blood products, especially in platelets that are stored at room temperature, is the most common infectious risk of blood transfusion, occurring in approximately 1 in every 2,000-2,500 platelet transfusions (Hong, 2016; Levy, 2018). Transfusion–transmitted sepsis, while less common, can cause severe illness and death. Improved donor screening as well as improved methods of collection, handling, and storing of blood products has decreased bacterial contamination in recent years.

• Gram–positive bacteria

  Gram-positive bacteria normally found on skin, such as Staphylococcus epidermidis or Staphylococcus aureus, are the most common bacterial contaminants of blood products. This type of contamination is thought to occur when the bacteria on a donor’s skin is passed into the collected blood through the collection needle.

• Gram-negative bacteria

  Gram-negative bacteria are part of the normal flora in the gastrointestinal tract (intestines). These bacteria can move from a person’s gastrointestinal tract to their bloodstream, causing infections of varying severity. Contamination of blood products with gram-negative bacteria is thought to occur when blood is collected from donors who have bacteria in their bloodstream but do not have symptoms of an infection. Examples include Acineobacter, Klebsiella (https://www.cdc.gov/HAI/organisms/organisms.html#k), and Escherichia coli (E. coli). Some gram-negative bacteria are resistant to multiple drugs and are increasingly resistant to many available antibiotics.

• Anaplasmosis

  Anaplasmosis is a tick-borne disease caused by the bacterium Anaplasma phagocytophilum. It is transmitted to humans by tick bites, primarily from the black-legged tick and the western black-legged tick, and can be transmitted via blood product from an infected donor (McFee, 2018). Symptoms of anaplasmosis include fever, headache, chills, and muscle aches.

• Brucellosis

  Brucellosis is a disease caused by Brucella bacteria, which are transmitted to humans from contact with infected animals such as sheep, cattle, and dogs. Human brucellosis is uncommon in the United States, but globally it affects nearly half a million people annually. Brucellosis has been previously described to be transmissible via blood product from an infected donor (Shakir, 2020). Symptoms include fever, sweats, headache, and fatigue.

• Ehrlichiosis

  Ehrlichiosis is a group of tick-borne diseases caused by Ehrlichia bacteria. The bacteria are transmitted to humans mainly through the bite of infected ticks including the lone star tick and the blacklegged tick. Transmission via blood product from an infected donor has previously been documented (Regan, 2013). Symptoms include fever, chills, headache, and muscle aches.

Bacterial Contamination of Platelets: Summary for Clinicians on Potential Management Issues Related to Transfusion Recipients and Blood Donors

Recommended handling and bacteriologic work-up of blood components

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. https://doi.org/10.1182/blood-2015-07-655944.

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, https://doi.org/10.1093/cid/cit177

Shakir R. Brucellosis. J Neurol Sci. 2021 Jan 15;420:117280. doi: 10.1016/j.jns.2020.117280. Epub 2020 Dec 21. PMID: 33358192.

Transmission of parasitic infections through blood transfusion is rare. To help minimize the risk of transfusion-transmitted illnesses, including parasitic infections, donors are asked questions to assist in determining if they are in good health. To reduce the risk of transmitting specific infections (e.g., malaria), donors are asked about recent travel to areas where these specific infections are more common. Examples of parasitic diseases that can be transmitted by blood transfusion are listed below.

• Babesiosis

  Babesiosis is caused by microscopic parasites that infect red blood cells and are spread by certain ticks. In the United States, tick-borne transmission is most common in particular regions and seasons: it mainly occurs in parts of the Northeast and upper Midwest and usually peaks during spring through fall.

• Chagas Disease

  Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insects. Trypanosoma cruzi is found only in the Americas, and transmission of the parasite occurs mainly in rural areas of Latin America. Since 2007, first time blood donors in the United States have been screened for antibodies to T. cruzi, making the risk of transfusion-transmitted Trypanosoma cruzi infection extremely rare.

• Leishmaniasis

  Leishmaniasis includes two major diseases, cutaneous leishmaniasis (infection involves the skin) and visceral leishmaniasis (infection involves internal organs, including the spleen, liver, and bone marrow), caused by infection with over 20 species of Leishmania parasites. Leishmaniasis is transmitted by the bite of small insects called sand flies. Several transfusion-transmitted cases of visceral leishmaniasis have been reported.

• Malaria

  Malaria is a serious and sometimes fatal disease caused by a parasite that commonly infects a certain type of mosquito that feeds on humans. People who get malaria are typically very sick, with high fevers, shaking chills, and flu-like illness. However, it does not always cause severe illness, and infections are of concern in blood donors when they cause sub-clinical or mild disease. 2,000 cases of malaria are diagnosed in the United States each year. The vast majority of cases in the United States are in travelers and immigrants returning from countries where malaria transmission occurs, including sub-Saharan Africa and South Asia.

Like bacteria and parasites, viruses that are blood-borne can be transmitted by blood transfusion. Donors are asked questions about their social behavior and health history to help minimize the risk of transfusion-transmitted viral diseases. Examples of viral diseases that can be transmitted through transfusion are listed below:

• Chikungunya Virus

  Chikungunya virus is an arbovirus spread to humans from mosquitos. Chikungunya outbreaks have occurred in Africa, Asia, Europe, the Indian and Pacific Oceans, and the Caribbean. Chikungunya was rarely identified in U.S. travelers until 2014, when cases were reported among U.S. travelers returning from affected areas in the Americas, and local transmission was identified in Florida, Texas, Puerto Rico, and the U.S. Virgin Islands. Symptoms include fever and joint pain, and there is no vaccine or medicine to prevent or treat Chikungunya.

• Dengue Fever

  Dengue fever is caused by any one of four related dengue viruses transmitted by Aedes species mosquitoes. With more than one-third of the world’s population living in areas at risk for transmission, dengue infection is a leading cause of illness and death in the tropics and subtropics. As many as 400 million people are infected yearly.

• Hepatitis A Virus

  Hepatitis A is a liver infection caused by the hepatitis A virus (HAV). Hepatitis A is spread primarily by the fecal-oral route, but transfusion-transmitted HAV infection has been reported. Hepatitis A can range in severity from a mild illness lasting a few weeks to a severe illness lasting several months, and in rare occasions can cause death.

• Hepatitis B Virus

  Hepatitis B is a liver infection caused by the hepatitis B virus (HBV). Up to 2.4 million Americans are living with chronic hepatitis B; most are unaware of their infection. Over time, approximately 15%–25% of people with chronic hepatitis B develop serious liver problems, including liver damage, cirrhosis, liver failure, and liver cancer. Every year, approximately 3,000 people in the United States and more than 800,000 people worldwide die from hepatitis B-related liver disease. Since 1972, the blood supply in the United States has been screened for hepatitis B, making the risk of transfusion-transmitted HBV extremely rare.

• Hepatitis C Virus

  Hepatitis C is a liver infection caused by the hepatitis C virus (HCV). Hepatitis C is the most common chronic bloodborne infection in the United States. Around 2.4 million Americans are living with chronic hepatitis C; most are unaware of their infection. Chronic hepatitis C is a serious disease that can result in long-term health problems, including liver damage, cirrhosis, liver failure, and liver cancer. Since 1992, the blood supply in the United States has been screened for hepatitis C, making the risk of transfusion-transmitted HCV extremely rare.

• Hepatitis E Virus

  Hepatitis E is a liver infection caused by the hepatitis E Virus (HEV). HEV is transmitted via the fecal-oral route, generally though contaminated water in areas with poor sanitation. Although HEV is rare in the United States, it is more common in other countries. Hepatitis E-related liver disease is usually self-limited and does not lead to chronic infection.

• Human Immunodeficiency Virus (HIV)

  HIV is the virus that causes acquired immune deficiency syndrome, or AIDS. HIV is typically transmitted through anal or vaginal sex or sharing needles, syringes, or other drug injection equipment. In 2019, 36,801 people received an HIV diagnosis in the United States and dependent areas. An estimated 1,189,700 people in the United States had HIV at the end of 2019, the most recent year for which this information is available. The risk of transfusion-transmitted HIV is extremely low due to the rigorous testing of the U.S. blood supply.

• Human T-Cell Lymphotrophic Virus (HTLV)

  HTLV is a viral infection common in Japan, sub-Saharan Africa, the Caribbean Islands, and South America. HTLV can be spread from mother to child (primarily through blood or breast milk), through sexual contact, or via infected blood products. Though many infected people do not have symptoms, HTLV can lead to neoplastic diseases, inflammatory syndromes, and opportunistic infections.

• West Nile Virus

  West Nile virus (WNV) can cause severe illness. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. Symptoms of WNV include fever, headache, fatigue, body aches, joint pain, and sometimes rash. Although WNV is most often transmitted by the bite of infected mosquitoes, the virus can also be transmitted through contact with infected animals, their blood, or other tissues.
  West Nile Virus Transfusion: Questions and Answers

• Yellow Fever Virus

  Yellow fever virus is found in tropical and subtropical areas of Africa and South America. The virus is spread to people by the bite of an infected mosquito. Illness ranges from a fever with aches and pains to severe liver disease with bleeding and yellowing skin (jaundice). Yellow fever infection is diagnosed based on laboratory testing, a person’s symptoms, and travel history. There is no medicine to treat or cure infection. To prevent getting sick from yellow fever, use insect repellent, wear long-sleeved shirts and long pants, and get vaccinated.

• Zika Virus

  Zika virus is a mosquito-borne arbovirus spread by the Aedes species mosquito. Zika virus can be passed from a pregnant woman to her fetus, and infection during pregnancy can lead to serious birth defects. Symptoms of Zika are generally mild and include fever, rash, headache, joint pain, red eyes, and muscle pain. FDA has determined that Zika is no longer a relevant transfusion-transmitted infection because the available evidence suggests that the incidence and prevalence of Zika infection is not high enough to affect the potential donor population.

Prion Diseases

Prion diseases or transmissible spongiform encephalopathies (TSEs), are a family of rare, progressive neurodegenerative disorders that affect both humans and animals. The causative agent of TSEs is believed to be a prion. A prion is an abnormal, transmissible agent that is able to induce abnormal folding of normal cellular prion proteins in the brain, leading to brain damage and the characteristic signs and symptoms of the disease. Prion diseases are usually rapidly progressive and always fatal. Like viruses, bacteria, and parasites, prions are bloodborne and may be transmitted by blood transfusion.

• Variant Creutzfeldt-Jakob Disease (vCJD)

  Variant Creutzfeldt-Jakob Disease (vCJD) is a rare, rapidly progressing neurologic disease that causes dementia and death. In 1996, cases of this variant form of Creutzfeldt-Jakob Disease (vCJD) were first reported in the United Kingdom. Transmission of vCJD in the United Kingdom has been thought to be related to transfusions received years earlier with non-leukoreduced red blood cells from healthy donors who became ill with vCJD months to less than 4 years after the donations. Recipients of blood components from other donors later diagnosed with vCJD remain under surveillance in the United Kingdom and France. The magnitude of the risk of acquiring vCJD from transfusion is uncertain.