# Extended Duration of Anti-HEV IgM Seropositivity in Asymptomatic Blood Donors: Implications for Transfusion Safety

## TL;DR

This study shows that some blood donors without symptoms or active HEV infection can have HEV IgM antibodies for up to seven months, raising concerns for transfusion safety.

## Contribution

The study reveals prolonged anti-HEV IgM seropositivity in asymptomatic individuals, challenging assumptions about HEV infection duration and detection.

## Key findings

- 1.3% of blood donors had positive HEV IgM without PCR-detectable viremia.
- Anti-HEV IgM positivity persisted for up to seven months in asymptomatic individuals.
- Stored samples confirmed prolonged IgM antibody presence in eight individuals.

## Abstract

Infection with Hepatitis E Virus (HEV) is often asymptomatic but can also lead to chronic infection in immunosuppressed individuals. Although fecal–oral transmission of HEV is well established, transmission by blood transfusion has also been reported. Here, we studied HEV seroprevalence in a cohort of 1000 blood donors (50% male, age 18–73 years, mean 35 years) at the University Medical Center Hamburg–Eppendorf in Germany. We found a seroprevalence of anti-HEV IgG of 16.6%. Interestingly, 1.3% of the blood donors had positive IgM serology despite testing negative for HEV by polymerase chain reaction (PCR). Analysis of preceding and follow-up samples showed persistence of IgM antibodies for up to seven months in asymptomatic individuals. In eight individuals, anti-HEV IgM positivity persisted for 0 to 7 months (median 2 months), as confirmed by testing stored samples. This study demonstrates that anti-HEV IgM positivity can persist for more than six months in individuals who had neither clinically overt hepatitis E nor a viremia duration that would allow PCR positivity to be detected.