Prevalence of HEV infection in acute non-ABC hepatitis and prognostic role of extrahepatic manifestations

Background: HEV-3 and HEV-4 are emerging cause of zoonotic acute hepatitis in high-income countries. In Europe the disease is underdiagnosed but hyperen-demic areas have been identified. We describe a population with acute non-ABC (n-ABC) hepatitis in Abruz-zo, the Italian region with the highest seroprevalence reported. The study was included in the surveillance of acute hepatitis E by the Italian Institute of Public Health started in 2004 and implemented in 2015. Methods: Patients with n-ABC hepatitis during 2004-2018 in all Abruzzo Infectious Disease Departments were tested for HEV-IgM (Wantai®) and HEV-RNA (ORF3). Positive samples were sequenced (Beckman Coulter®) and phylogenetic tree (MEGA 6.06 software) obtained. Clinical data were retrospectively collected and an al-imentary risk factors-questionnaire was administered. Categorical and quantitative variables were compared (Chi square test or Fisher test and Wilcoxon test). Results: 97 hospitalized patients were tested, most cases (91.7%) after 2015. Overall, HEV-IgM resulted positive in 36% and HEV-RNA detectable in 33.3%. All 24 sequences obtained were HEV-3, with two small groups of closely related strands. L’Aquila was the Province with higher positivity rate (44%). Retrospective clinical data were acquired in 86.5% of patients, no one having liver failure. Higher ALT-levels (1282.34 vs 893.25, p=0.0139) and extrahepatic symptoms (OR 16.69, p=0.0018) were strongly associated with HEV-IgM presence. Two small outbreaks are described. Conclusions: More than one third of n-ABC hepatitis in all Abruzzo are HEV-related. Extrahepatic symptoms correlate with HEV aetiology. Implementing surveillance is mandatory to really understand the extent of the disease.