CD40LG and animal viral hepatitis: HEV seroprevalence estimates were variable, while two studies in viral hepatitis patients showed anti-HEV proportions of 7.5% and 25.3% for IgG and of 1.74% and 5.6% for IgM (27, 33), the reported HEV IgG seroprevalence was 45.2% in blood donors (29).