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 the most frequently transmitted viral pathogen through blood transfusions, as noted in studies such as 1. This is partly due to the virus's ability to remain undetected during the "window period" between infection and the development of detectable antibodies. HCV can cause chronic liver disease in approximately 75-85% of infected individuals, potentially leading to cirrhosis and hepatocellular carcinoma.
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, as discussed in 1 and 1. Modern blood banks employ nucleic acid testing (NAT) to detect viral RNA directly, which has significantly reduced but not completely eliminated the risk of HCV transmission. More recent studies, such as 1 and 1, highlight the importance of continued vigilance and the introduction of new screening methodologies for other viruses like HEV, but they do not alter the fact that HCV remains a significant concern in the context of blood transfusions.
Key points to consider include:
- The risk of HCV transmission through blood transfusion has been significantly reduced but not eliminated.
- Improved screening methods, including NAT, have been instrumental in reducing transmission rates of various pathogens.
- HCV can lead to severe long-term health consequences, including chronic liver disease, cirrhosis, and hepatocellular carcinoma.
- Other viruses, such as HEV, are also of concern in the context of blood transfusions, especially in immunosuppressed recipients, as noted in 1 and 1.
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.
Comparison of Infection Risks
While all the options (a, b, c, d) are potential transfusion-transmitted infections, the studies do not provide a clear ranking of the most common agent. However, HBV is highlighted as a significant risk in several studies 3, 4, 5, 6.
Key Findings
- The risk of transfusion-transmitted infections has been reduced significantly with the implementation of nucleic acid testing (NAT) and other safety measures 2, 5.
- HBV NAT combines the ability to significantly reduce the window period and to detect occult HBV carriage 3.
- The estimated risk for infection by screened blood components is approximately 1 in 50,000 to 1.6 million for HBV, HCV, and HIV-1/2 4.