Transfusion Transmitted Infection Prevention – Christoph Niederhauser


Hepatitis E is a mild, self-limiting disease without chronic sequelae and is mostly asymptomatic. Experiments involving the transfusion of blood or plasma from anti-HEV IgM positive and anti-HEV IgG negative blood donors to Rhesus monkey demonstrated the transmissibility of the virus through transfusions. This fact explains the probability of blood donation by viraemic but asymptomatic donors, and hence transfusion-transmitted HEV (TT-HEV) infection. Several reports have described symptomatic hepatitis E cases that were attributed to the transfusion of proven HEV-contaminated blood components. Transmission of HEV through solid-organ transplantation and stem cell transplantation has also been reported. The proportion of transplant patients with chronic liver injury due to TT-HEV is not completely assessed. These patients are exposed to the risk of HEV infection on a daily basis via the food and water they consume. In addition, due to a continuous and lifelong immunosuppressive treatment, transplant recipients are at risk of developing chronic HEV infection. Finally, the transfusion of HEV contaminated blood products can lead to infection of these recipients.

The aim of this nationwide cross-sectional study is to determine the prevalence and incidence of chronic HEV infection in the Swiss solid-organ and stem cell transplant recipients population. The HEV RNA and anti-HEV IgG status of solid-organ and allogeneic stem cell recipients will be evaluated by testing of pre- and post-transplantation archive samples. In addition, liver function tests (such as ALT, AST, bilirubin, etc.) and, if available, clinical signs giving a hint for an active hepatitis, will be collected from recipient records. If HEV RNA positive transplant recipients received blood components, the corresponding archive samples of the donations will be tested for HEV RNA and anti-HEV IgM.

A second study concerning the Hepatitis E virus addresses the same question from the perspective of blood product producer. Since October 2018 HEV RNA screening is mandatory for all blood donors. The questions that should be answered are, what’s the incidence of RNA positive donors, how is their serological status, what genotypes are involved and which viral loads are found. The main question is which viral could still be infectious and what’s the optimal strategy to avoid transfusion-transmitted infections.