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Hepatitis E virus screening in Irish blood donors: Seven years of individual donation nucleic acid testing reveals a frequent blood donor infection—but what is the risk?

Year: 2025

Type: article

Abstract: Background Screening blood donations for HEV RNA mitigates the risk of transfusion‐transmitted HEV infection (TT‐HEV), a recognised blood safety issue in Europe. This study reports the findings of government‐funded HEV RNA blood donation screening 2016–2022 and includes an estimate of residual risk. Method Donation samples were universally and individually tested for HEV RNA using the Procleix HEV assay. Repeat reactive samples were referred for further molecular (PCR, viral load, genotyping) and serological analyses. A previously described model was used for the estimation of residual risk. Results 229 HEV RNA positive donations were identified in 980 690 donations. Serological window period donations accounted for 148 (65%) of cases. HEV RNA donation positivity ranged from 1 in 6153 (0.016%) to 1 in 2314 (0.043%). In the absence of screening and with a residual plasma volume of 10 mL, >19% of the Hepatitis E virus positive Red Cell Concentrates ( n = 42/220) could have resulted in transmission. The residual risk, based on a window period of 14 days was estimated at 51 per million donations. At least 15 components with infectious doses of >1 × 10 6 IU were interdicted. Conclusions Autochthonous asymptomatic HEV infection continues to occur in Irish donors with relative frequency. As donors with higher viral loads can lead to infectious donations, the value of screening the blood supply for HEV is evident and supported by an absence of reported TT HEV cases. Interventions to control foodborne HEV may reduce the relative benefit of screening in the future.

Source: Transfusion Medicine

DOI: 10.1111/tme.70047