HEV-positive blood donations represent a relevant infection risk for immunosuppressed recipients.

Background & Aims: Routine HEV testing of blood products has recently been implemented in Great Britain and the Netherlands. The relevance of transfusion-transmitted HEV infections is still controversially discussed in Europe.

Methods: All blood donations at the University Medical Center Hamburg-Eppendorf were prospectively tested for HEV RNA by pooled PCR from October 2016 to May 2017. Reactive samples were individually retested. Additionally, stored samples from previous donations of positive donors were tested to determine the duration of HEV viraemia. HEV RNA-positive donors and a control cohort were asked to answer a questionnaire.

Results: Twenty-three out of 18,737 HEV RNA-positive donors were identified (0.12%). Only two of the positive donors (8.7%) presented with elevated aminotransferases at time of donation (alanine aminotransferase: 192 and 101 U/L). The retrospective analysis of all positive donors revealed that four asymptomatic donors had been HEV viraemic for up to three months with the longest duration of HEV viraemia exceeding four months. Despite the HEV-testing efforts, 14 HEV RNA-positive blood products were transfused into 12 immunocompromised and two immunocompetent patients. One recipient of these products developed fatal acute-on-chronic liver failure complicated by Pseudomonas septicemia. The questionnaire revealed that HEV RNA-positive donors significantly more often consumed raw pork meat (12 out of 18; 67%) than controls (89 out of 256; 35%; p = 0.01). In two donors, undercooked pork liver dishes were identified as the source of infection. HEV genotyping was possible in 7 out of 23 of HEV viraemic donors and six out of seven isolates belonged to HEV Genotype 3, Group 2.

Conclusions: Prolonged HEV viraemia can be detected at a relatively high rate in Northern German blood donors, leading to transfusion-transmitted HEV infections in several patients with the risk of severe and fatal complications. Eating raw pork tartare represented a relevant risk for the acquisition of HEV infection.

Lay Summary: The relevance of transfusion-transmitted hepatitis E virus infections has been discussed controversially. Herein, we present the first report on routine hepatitis E virus screening of blood donations at a tertiary care centre in Germany. Hepatitis E viraemia was found at a relatively high rate of 0.12% among blood donors, which represents a relevant transfusion-related risk for vulnerable patient populations.