Correspondence (letter to the editor): Current Data

Hepatitis E is relevant in the context of blood transfusions (1). In addition, and in order to contribute to the discussion surrounding the safety of blood products, we wish to draw attention to recent data on transfusion associated hepatitis E. We have shown recently that low concentrations of hepatitis E virus (HEV)-RNA of 120 international units (IU)/ml in the plasma of an asymptomatic multiple donor were sufficiently high to result in chronic HEV infection in an immunosuppressed recipient (2, 3). The transmitted infectious dose was calculated for the first time and was 7056 IU HEV-RNA in the transfused platelet apheresis preparation. A further possible transmission occurred in a child from the same donation (2). The conclusion is, firstly, that a low concentration of HEV can be enough to cause HEV infection, and, secondly, that highly sensitive PCR methods are required to detect HEV-RNA in blood donors. Vollmer et al. showed that PCR based HEV screening with sufficiently high sensitivity is possible and can easily be integrated into existing test algorithms (3).

Studies imply that 1600–5900 HEV-RNA positive blood donations are to be expected in Germany per year (1– 3). Multiple donations during the viremic phase and dividing the blood product among several recipients increase the risk of infection even more. Although immunocompromised patients are a relevant recipient group for blood products, the disease burden of transfusion associated hepatitis E is not comprehensively known. The reasons include a perception that underestimates hepatitis E (4). For the purposes of a safe provision of blood products and in view of the risk of severe disease courses, the obvious step seems to be to introduce HEV screening, in analogy to hepatitis C and HIV. Evidence based data on the relevance, cost effectiveness, and feasibility of HEV screening in blood donors are, however, still lacking.