Prevalence and 9-year incidence of hepatitis E virus infection among north italian blood donors: Estimated transfusion risk

Recent European guidelines recommend that screening policiesfor Hepatitis E virus (HEV) in blood donors should be based on local risk assessments. We determined the prevalence of current and past HEV infection in donors from Lombardy, the Italian region providing 24% of the Italian blood supply. We also calculated the incidence of infection over a period of 10 years, and estimated the risk of transfusion-related transmission. The study was conducted within the framework of BOTIA, an EU-funded project. HEV RNA was detected by individual donation testing, and the prevalence and incidence of anti-HEV antibodies were determined in two subgroups. The risk of receiving an infected blood unit was estimated on the basis of HEV RNA yields and serology. RESULTS: One of the 9726 donors was truly viremic. The prevalence of confirmed anti-HEV IgG reactivity was 52/767 (6.8%; 95%CI 5.1-8.8%). The incidence of HEV infection was 7.6/10000 per year (95%CI 2.1-2.5 per year). The estimated transfusion-related risk of infection was 1/10000 blood donations on the basis of HEV RNA yield (upper limit of the 95%CI 1:1666), and 1/16666 donations on the basis of the incidence data (95%CI 1:435-1:57000).In conclusion, The frequency of current and past HEV infection in blood donors living in Northern Italy is among the lowest so far reported in Europe. The estimated transfusion-related risk of infection was similar regardless of whether it was calculated on the basis of HEV RNA yield or serological incidence, thus suggesting stable infection pressure over the last ten years.