What is the most common microbial agent transmitted through blood transfusion?

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From the Guidelines

The most common microbial agent transmitted by blood transfusion is (c) hepatitis C virus. Hepatitis C virus (HCV) remains a significant concern in transfusion medicine due to its potential to cause chronic infection and liver damage. Although screening methods have improved, HCV can still be transmitted through blood transfusions, particularly during the window period before the virus is detectable by current tests 1.

Key Points:

  • HCV has a high rate of chronic infection, with approximately 75-85% of infected individuals developing chronic hepatitis.
  • Blood banks screen donated blood for HCV antibodies and viral RNA, but there remains a small window period during early infection when tests may not detect the virus.
  • Other pathogens like HIV, hepatitis B virus, and cytomegalovirus can also be transmitted through blood transfusions, but their transmission rates have been significantly reduced through improved screening techniques.
  • Recent studies have highlighted the importance of screening for other viruses, such as hepatitis E virus (HEV), which can also be transmitted through blood transfusions, particularly in immunosuppressed individuals 1. However, based on the most recent and highest quality evidence, HCV remains the most common microbial agent transmitted through blood transfusions. It is essential to continue improving screening methods and monitoring for emerging threats like HEV to minimize the risk of transfusion-transmitted infections.

From the Research

Transfusion-Transmitted Infections

The most common microbial agents transmitted by blood transfusion include:

  • Hepatitis B virus (HBV)
  • Hepatitis C virus (HCV)
  • Human immunodeficiency virus (HIV)
  • Cytomegalovirus (CMV)

Prevalence of Transfusion-Transmitted Infections

According to various studies 2, 3, 4, 5, 6, HBV remains a major risk of transfusion-transmitted infection due to the pre-seroconversion window period, infection with immunovariant viruses, and occult carriage of HBV infection.

Risk of Transfusion-Transmitted Infections

The risk of transfusion-transmitted infections has been reduced significantly with advanced technologies and improved donor screening 6. However, the risk of transmission still exists, particularly for HBV, which can be transmitted even with negative serological tests and NAT results 3, 6.

Comparison of Transfusion-Transmitted Infections

While all the options (a, b, c, d) are potential transfusion-transmitted infections, the most common one is not explicitly stated in the provided studies. However, based on the information provided, it can be inferred that HBV is a significant risk due to its window period and occult carriage 3.

Key Findings

Key findings from the studies include:

  • HBV remains a major risk of transfusion-transmitted infection 3
  • Advanced technologies, such as NAT, have reduced the risk of viral transmission 2, 4, 6
  • The risk of transmission still exists, particularly for HBV 3, 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Transfusion-transmitted infectious diseases.

Biologicals : journal of the International Association of Biological Standardization, 2009

Research

Transfusion-transmissible infections.

Current opinion in hematology, 1998

Research

Transfusion-transmitted hepatitis virus infection.

Hematology/oncology clinics of North America, 1995

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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