Hepatitis C is the Most Common Virus Transmitted by Blood Transfusion
Hepatitis C virus (HCV) is the most common virus transmitted through blood transfusion. 1 According to CDC guidelines, HCV has historically been the primary viral agent responsible for transfusion-associated hepatitis, with studies showing that 90% of post-transfusion hepatitis was not due to either hepatitis A or B, but rather to HCV.
Historical Context and Epidemiology
- In the 1960s, post-transfusion hepatitis rates exceeded 20% 1
- By the mid-1970s, diagnostic testing revealed that 90% of post-transfusion hepatitis was not caused by hepatitis A or B viruses 1
- Before screening was implemented, HCV (previously called non-A, non-B hepatitis) accounted for 15-20% of community-acquired viral hepatitis in the United States 1
- During the 1980s, an estimated 230,000 new HCV infections occurred annually in the US 1
Transmission Risk Reduction Over Time
The risk of acquiring viral infections through blood transfusions has dramatically decreased due to improved screening methods:
- Before 1990: Blood transfusion accounted for a substantial proportion of HCV infections 1
- 1990: Routine testing of donors for HCV infection was initiated 1
- 1992: More sensitive multi-antigen testing was implemented 1
- Current risk: Approximately 0.001% per unit transfused (compared to 10% in the late 1970s) 1
Comparison with Other Transfusion-Transmitted Viruses
Hepatitis B Virus (HBV)
- HBV screening began in 1969 and became mandatory in 1972 1
- Current incidence of post-transfusion hepatitis B is estimated to be around 0.002% per transfusion recipient 1
- HBV transmission by transfusion is now rare due to mandatory screening 1
HIV
- HIV screening has drastically reduced transmission risk 2
- Current risk is between one and four per million blood components transfused 3
Current Risk Status
In developed countries with modern blood screening practices:
- The current risk of transfusion-transmitted viral infection (including HBV, HCV, and HIV) is estimated to be less than 2.5 per 1 million donations 1
- Despite advanced technologies, zero risk has not yet been achieved 4
Clinical Implications
The burden of HCV-related disease remains significant:
- Chronic liver disease is the tenth leading cause of death among adults in the US 1
- 40% of chronic liver disease is HCV-related, resulting in an estimated 8,000-10,000 deaths per year 1
- HCV-associated end-stage liver disease is the most frequent indication for liver transplantation among adults 1
While modern screening has dramatically reduced the risk of transfusion-transmitted HCV, it remains the virus historically most commonly transmitted through blood transfusion, with the highest prevalence among those who received transfusions before effective screening was implemented.