The most common way of Hepatitis E virus (HEV) transmission in developed countries is food-borne zoonosis, but HEV can also be transmitted by transfusion of infected blood and blood products or transplantation of infected organs. In case infected blood or blood products are transfused to immunocompromised patients, there is a high risk of chronic hepatitis E development or even hepatic failure and death. Currently, there is no routine testing of donated blood units for HEV infection in place in Republic of Slovenia, so the risk of HEV transmission with infected blood is significant. The aim of master thesis study was to determine the incidence of acute HEV infection and the seroprevalence of anti-HEV IgG antibodies among Slovenian blood donors. To determine incidence and seroprevalence of HEV infection we tested 9284 blood plasma samples for HEV RNA reactivity using the Transcription Mediated Amplification (TMA) technology, and 1236 out of these were also serologically tested for anti-HEV IgG antibodies. Anti-HEV IgG reactive samples were further tested for anti-HEV IgM antibodies. Genotyping and quantitative NAT of HEV RNA reactive samples was performed by Centre National de Reference Hepatitis E, Toulouse, France.
Among 9284 tested samples 5 were reactive to HEV RNA and 2 out of those were also reactive to anti-HEV IgG and IgM antibodies. We followed-up all 5 HEV RNA reactive blood donors until the end of viremic phase. HEV genotype was successfully determined in 4 out of 5 samples (3 cases of 3a and 1 case of 3f genotype). The range of viral load in index blood samples was from 16 to 18,700 IU/mL. The presence of anti-HEV IgG antibodies was confirmed in all five HEV RNA reactive blood donors from 0 to 105 days after the index donation. Among 1263 samples tested for anti-HEV IgG antibodies 94 were reactive (7,4%). Three out of these 94 were anti-HEV IgM reactive as well, but HEV RNA nonreactive.
Results show 1:1857 incidence of HEV infection among Slovenian blood donors, which means 1 in every 1857 blood donations is compromised. The seroprevalence of anti-HEV IgG antibodies among Slovenian blood donors is 7,4%. The incidence is comparable to the HEV incidence in other European countries for which data is available. The seroprevalence of HEV infection in Slovenia is among lowest in Europe.