Hepatitis E virus (HEV) infection is most often acquired through contaminated food and drinking water. In particular, pork is a common source of transmission.
HEV is a small, non-enveloped virus that can be inactivated or removed by various steps in the manufacturing process for fractionated plasma products. There is no evidence of transmission of HEV infection by products used to treat bleeding disorders.
HEV infection can be a problem for immunosuppressed or immune-compromised patients. For example, chronic hepatitis E has been observed in organ transplant recipients including liver transplants (which are relevant to our community), patients with hematologic tumours, patients after allogeneic hematopoietic stem cell transplantation, and HIV-infected patients with low CD4 cell counts. For this reason, it is important to screen such patients for HEV infection, since treatment for HEV infection with ribavirin has been shown to be effective in at-risk patients.
Regulators are continuing to study and evaluate the situation with HEV in many countries. Regulators in some European countries are considering screening donors, although transmission of HEV through fresh blood components is very rare. At this time, the most effective method for prevention of HEV outbreaks is to focus on clean drinking water and a safe food supply. The WFH will continue to monitor HEV, in particular the risks to immune-compromised patients, the effectiveness of treatment, and testing methods for patients and plasma pools.
For more information, consult the following articles:
Kamar – Ribavirin for Chronic Hepatitis E Virus Infection in Transplant Recipients
N Engl J Med 2014;370:1111-20
Hepatitis E Virus – German Advisory Committee Blood (Arbeitskreis Blut), Subgroup ‘Assessment of Pathogens Transmissible by Blood’
Transfus Med Hemother