Both animals and humans can be infected. HEV infection usually causes no symptoms, if it does cause symptoms they are generally mild. Normally the virus infection will clear by itself. However, it is known that patients whose immune system is suppressed (eg chemotherapy or transplant patients) can have a more serious illness if they contract Hepatitis E. You will be informed if the virus is found in your donation.
Donors cannot donate until at least 6 months have passed since recovery from Hepatitis E infection. Alternatively, if a blood test taken when a donor feels fully recovered shows clearance of the virus nuclei acid and the development of immune antibodies then they can donate again before this 6 month period.