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Published on: July 16, 2012
HCV viral load in anti-HCV-reactive donors and infectivity for their recipients
Eva A Operskalski1, James W Mosley, Leslie H Tobler
1Transfusion Viruses Program, Keck School of Medicine, University of Southern California, Los Angeles, California 90089-9560, USA. eva@usc.edu
Insights
Hepatitis C virus (HCV) RNA testing cannot identify all infectious donations, even with sensitive assays. Continued serologic screening is crucial to prevent transfusion-transmitted HCV infections.
Area of Science:
- Transfusion Medicine
- Virology
- Public Health
Background:
- Hepatitis C virus (HCV) transmission through blood transfusions remains a concern.
- Determining the minimum level of HCV nucleic acid in donors is vital for transfusion safety.
- Understanding transmission dynamics informs blood screening strategies, including assay sensitivity and testing methods.
Purpose of the Study:
- To ascertain the minimum level of HCV RNA in blood donors associated with recipient infection.
- To evaluate the efficacy of current HCV testing methods in preventing transfusion transmission.
- To assess the necessity of continued serologic screening for HCV.
Main Methods:
- Screening of 5387 blood donations from the 1970s for anti-HCV antibodies.
- Analysis of recipient outcomes, including viremia and seroconversion, from seroreactive donations.
- Utilizing third-generation EIA, RIBA, quantitative RT-PCR, and transcription-mediated amplification (TMA) assays.
Main Results:
- 156 recipients from 180 anti-HCV-reactive donors were identified.
- 98% of recipients transfused with quantifiable HCV RNA by RT-PCR seroconverted.
- All 10 recipients receiving TMA-detectable, RT-PCR-undetectable units seroconverted, highlighting transmission at low viral loads.
Conclusions:
- High rates of HCV transmission occur even at low levels of viremia.
- Current HCV RNA testing methods, including TMA, may not detect all infectious units.
- Continued serologic screening for HCV is essential to prevent transfusion-transmitted infections.
Background:
An attempt has been made to determine the minimum level of HCV nucleic acid in donors associated with infection of recipients. This is important for considerations about assay sensitivity, use of minipool versus single-donation testing, and continued use of serologic testing.
Study Design And Methods:
A total of 5387 specimens from the Transfusion-Transmitted Viruses Study in the 1970s were screened for antibody to HCV (anti-HCV). The outcome in recipients of seroreactive donations was examined for viremia and seroconversion. Present techniques for both groups included third-generation EIA, RIBA, quantitative RT-PCR assay, and transcription-mediated amplification (TMA) assay.
Results:
A total of 156 recipients of components from 180 anti-HCV-reactive donors were identified. One-hundred seven of these were HCV-naïve before transfusion and received a single, confirmed seropositive unit; 94 (88%) became infected. Eighty-five recipients had donors whose HCV RNA level was quantifiable by RT-PCR (range, 182-3,310,000 copies/mL). Eighty-three (98%) seroconverted. Of the remaining 22, a total of 10 received units positive for HCV RNA detected only by TMA; all 10 recipients seroconverted. Of the remaining 12 recipients of anti-HCV+, TMA-negative units, 1 recipient seroconverted.
Conclusions:
High rates of transmission were seen at all levels of viremia, and one donor transmitted with undetectable levels in the TMA assay. Current HCV RNA testing will therefore not interdict all infectious units, even with single-donation testing, and serologic screening must be continued.
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