MIKROBIYOLOJI BULTENI, vol.49, no.4, pp.554-564, 2015 (SCI-Expanded)
Hepatitis E virus (HEV), classified in Hepeviridae family, Hepevirus genus, is a non-enveloped virus with icosahedral capsid containing single-stranded positive sense RNA genome. HEV infections may be asymptomatic especially in children, however it may present as fulminant hepatitis in pregnant women, as well as chronic hepatitis in immunocompromised patients. There are four well-known genotypes of HEV that infect humans and many mammalian species. Genotype 1 and 2 are frequently responsible for water-borne infections transmitted by fecal-oral way in developing countries, while genotype 3 and 4 cause zoonotic infections in developed countries. Turkey is considered as an endemic country with a total seroprevalence rate of 6.3% for normal population, showing significant variation (0-73%) according to the regions and study groups. The aims of this study were to investigate the HEV seropositivity in cases admitted to Hacettepe University Medical Faculty Hospital (HUMFH), to evaluate the results according to the demographic features of patients, and to determine the current HEV seroprevalence in our region, contributing seroepidemiological data in Turkey. A total of 1043 serum samples (514 female, 529 male; age range: 1-90 years, mean age: 38.03) obtained from 327 blood donors (32 female, 295 male; age range: 19-59 years, mean age: 31.1) who were admitted to HUMFH Blood Center, and 716 sera (482 female, 234 male; age range: 1-90 years, mean age: 41.7) that were sent to HUMFH Central Laboratory from various outpatient/inpatient clinics, between November 2012 to November 2013, were included in the study. The presence of HEV-IgG antibodies in serum samples was detected by a commercial ELISA method (Euroimmun, Germany), and the presence of HEV-IgM antibodies was also investigated in the sera with IgG-positive results. The overall HEV-IgG seropositivity rate was determined as 4.4% (46/1043), and the seropositivity rates for blood donors and in/outpatients were as 0.92% (3/327) and 6.0% (43/716), respectively. HEV-IgM antibody was not detected in any of the cases. The HEV-IgG seropositivity was 3.2% among male, and 5.6% among female, yielding no statistically significant difference between the gender (p=0.056). HEV-IgG antibodies were detected in none (0/118) of the pediatric age group (0-18 years), while the seropositivity rates were 1.9% (14/731) and 16.5% (32/194) in 19-55 and >= 56 years-old groups, respectively. The difference between the age groups was statistically significant (p<0.001), indicating the age-related pattern of HEV exposure. In conclusion, the total HEV seroprevalence rate found as 4.4% in our study, is comparable to the average results reported from Turkey. Our data is also in agreement with the result of a previous report (3.8%) that performed from Ankara province in 2002 with similar study groups, emphasizing that there was no significant changes for HEV exposure have occured over more than the last decade in Ankara, Cental Anatolia, Turkey.