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

From the Guidelines

The most common microbial agent transmitted by blood transfusion is hepatitis C virus (HCV), which corresponds to option (c). Despite significant improvements in blood screening procedures over the past decades, HCV remains a concern due to its ability to establish chronic infection in many carriers who may be asymptomatic and unaware of their infection status. HCV has a relatively long window period during which newly infected individuals may test negative on screening tests while still being infectious, as noted in studies such as 1. The virus primarily affects the liver and can lead to chronic hepatitis, cirrhosis, and hepatocellular carcinoma if left untreated. While other pathogens like HIV, hepatitis B virus, and cytomegalovirus can also be transmitted through blood transfusions, their transmission rates have been reduced more effectively through improved screening methods and donor selection criteria compared to HCV, as discussed in 1. Recent guidelines, such as those from 1 and 1, highlight the importance of screening for various hepatitis viruses, including HEV, in the context of blood transfusions, but HCV remains a primary concern due to its prevalence and impact on public health. Key points to consider include:

• The risk of transmitting HCV through blood transfusion has decreased significantly due to improved screening methods.
• HCV can lead to severe liver disease if not treated properly.
• Other viruses like HEV are also transmitted through blood transfusions, especially in immunosuppressed individuals, but HCV is notable for its chronic infection rate and liver disease potential.
• Screening blood donors for evidence of HCV infection, as well as other pathogens, is crucial for preventing transfusion-transmitted infections, as emphasized in 1.

From the Research

Microbial Agents Transmitted by Blood Transfusion

• The most common microbial agents transmitted by blood transfusion include:
  • Hepatitis B virus (HBV) 2, 3, 4, 5
  • Hepatitis C virus (HCV) 2, 4, 5
  • Human immunodeficiency virus (HIV) 2, 4, 5, 6
  • Cytomegalovirus (CMV) 2, 4
• HBV is considered a major risk of transfusion-transmitted infection due to the pre-seroconversion window period, infection with immunovariant viruses, and occult carriage of HBV infection (OBI) 3
• The risk of transmitting these infectious agents can be reduced by donor exclusion, screening for serological markers of infections, and nucleic acid testing (NAT) by viral gene amplification 2, 4, 5
• Coinfections of HBV, HCV, and HIV can cause severe morbidity and are complicated to treat due to side effects of antiviral medication and drug resistance 6