Seroprevalence of IgM and IgG Antibodies Directed Against Hepatitis E Virus in 4867 Blood Donors From Tyrol, Austria

Abstract

There may be a risk of transmitting Hepatitis E Virus (HEV) through blood transfusions, however screening blood donors for HEV is not mandatory in Austria. We assessed the seroprevalence of anti–HEV antibodies among blood donors, thereby informing about the risk of HEV-contaminated blood products. Between May and July 2022, we enrolled 4867 blood donors aged 18–70 years at 38 donation events spread across the Federal State of Tyrol, Austria. We measured anti–HEV IgG and IgM antibodies using five validated assays, based on which overall anti–HEV seropositivity was defined. We determined seroprevalences with 95% confidence intervals (CI) and calculated odds ratios for seropositivity using logistic regression. Median age of participants was 45.99 years (25th–75th percentile: 31.49–55.80); 41.15% were female, and 75.82% lived in rural areas. Anti–HEV IgM was detected in 13 individuals, i.e. 0.27% (95% CI: 0.16–0.47%). Anti–HEV IgG seroprevalence was 19.26% (18.17–20.40%) overall. It was higher in older blood donors – peaking in the 65–70–year age group (47.92%) –, higher in males (20.70%) than females (17.20%) and higher in urban (21.28%) compared to rural areas (18.61%). Multivariable adjusted odds ratios for IgG seropositivity were 1.19 for male sex (1.01–1.39; p = 0.033), 2.15 per 10–year older age (2.00–2.30; p < 0.001) and 1.21 for residing in an urban area (1.02–1.45; p = 0.030). Our findings indicate that HEV is widespread in Austria. Implementation of mandatory routine HEV nucleic acid testing should be considered in blood donations to enhance transfusion safety.