Correspondence (reply): In Reply

We thank our colleagues for their important comments. In recent years there have been numerous reports of hepatitis E virus (HEV) transmission through transfusions of blood products (1). Furthermore, the prevalence of HEV-RNA in blood products has been studied in several Western countries. The viral load in the respective blood product is associated with the risk of establishing infection; the case from Freiburg is consistent with the findings of a large prospective study from the UK (2). The study showed that low potentially infectious HEV-RNA contaminations can occur even in the absence of HEV specific antibodies and that direct testing for HEV-RNA is therefore required in every case, in order to prevent cases of HEV transmission. With regard to pooled plasma products it is necessary to point out that the standard protocols for viral inactivation (intercept method and solvent-detergent method) do not inactivate HEV in all cases (3). The clinical importance of transfusion-associated HEV infection is currently the subject of controversial discussion. Individuals receiving blood products can always become infected with HEV by various other ways and at any time, even if the blood products were tested for HEV-RNA. On the other hand, the consequences of undetected acute or chronic hepatitis E can be severe in individual cases. In our opinion, HEV-RNA testing of blood products is indicated if the intended recipients are immunocompromised or have chronic liver disease. It should also be borne in mind that HEV infection can potentially trigger numerous extrahepatic manifestations—for example, Guillaine-Barré syndrome or brachial plexus neuropathy (amyotrophic neuralgia). Prospective studies are needed to investigate if these rare disease entities can be prevented by means of stringent prevention of HEV transmission through blood products.