Aim. In Estonia, the diagnostics of hepatitis E virus (HEV) has not yet been performed and the occurrence of anti-HEV antibodies in the general population has never been studied. The aim of the study was to determine the presence of HEV in the general Estonian population.
Methods. From the bank of sera, Department of Virology, Estonian National Institute for Health Development a total of 1253 serum samples (494 males aged 20–91, mean age 46.4; SD14.8 and 759 females aged 20–82, mean age 44.4; SD14.6) were selected for a retrospective study. Among these, 763 samples were from patients with acute non-A,B,C hepatitis, 176 from hemodialysis patients, 163 from health care professionals (HCW) and 151 from healthy people. The samples were collected between 1994 and 2006 and stored at -70C before the study.
All serum samples were tested for presence of HEV IgG, positive sera were tested for HEV IgM antibodies using the recom-Well HEV IgG/IgM ELISA kits (Mikrogen, Denmark). All sera positive both for IgG and IgM were retested. For confirmation, anti- HEV IgG and IgM positive sera were tested with an immunoblot assay (recomLine HEV IgG/IgM, Mikrogen).
Results. Out of all sera, 3.2% (40/1253, 16 males, age range 23–74; 24 females, age range 22–73 years) were positive for anti-HEV IgG.
Anti-HEV IgM was found in 32.5% (13/40; 6 males and 7 females) of the anti-HEV IgG positive samples. Overall, 27 sera were only positiv for anti-HEV IgG. The highest HEV antibody occurrence, 6.0%, was noted in healthy subjects followed by 5.1% in the group of hemodialysis patients. For both health care professionals and patients with acute non-A,B,C hepatitis, the occurrence of antibodies was 2.4%. Comparison of the estimates by age revealed the highest occurrence rate (5.9%) in those aged 60 years and over.
Conclusions. These preliminary results demonstrate the incidence of HEV in Estonia and indicate that HEV should be considered a possible cause of viral hepatitis.
Since HEV diagnost ic s is not yet performed in Estonia, there is an urgent need for implementing the methods of diagnosing this disease in medical institutions. It is important to fi nd out whether or not there exist sporadic cases of human hepatitis E in Estonia and, if this is the case, which strains of HEV are responsible for them.