Hepatitis E virus seroprevalence and associated risk factors in high-risk groups: A cross-sectional study from Turkey

Background: The renal transplant recipients (RT), allogeneic hematopoietic stem cell transplant recipients (allo-HSCT), patients with acute hepatitis (AH), and chronic hepatitis C patients (CHC) are at risk of hepatitis E virus (HEV) infection. However, seroepidemiology, risk factors to HEV exposure, and the prevalence of HEV viremia has not yet been investigated among these patients in Turkey. Materials&Methods: In this cross-sectional study, 292 consecutive serum samples were tested for HEV immunoglobulin IgG/IgM and HEV RNA using commercial ELISA and in-house nested PCR with Sanger sequencing, respectively. Sociodemographic, clinical, laboratory data, and risk factors were collected using a questionnaire and hospital database. Multiple logistic regression analysis was employed to identify independent predictors for anti-HEV seropositivity. Results: Among all patients (n=292) tested for HEV RNA reactivity, only 2 patients (one RT recipient and one patient with AH) were identified as having HEV3 viremia. HEV viremia rate was 0.6% in whole group. These patients had shown no signs of chronic HEV infection for 6 months and was found to spontaneously seroconverted 6 months after enrollment. Anti-HEV IgG was positive in 29 patients yielding an HEV seroprevalence of 9.9%. Older age (aOR:1.03, 95% CI, 1.00-1.06; p:0.022) and eating undercooked meat (aOR:3.11, 95% CI, 1.08-8.92; p:0.034) were independent risk factors to anti-HEV seropositivity in all patients. Similarly, multiple logistic regression analysis demonstrated that age (aOR:1.03, 95% CI, 0.99-1.07, p:0.058) and eating undercooked meat (aOR:5.77, 95% CI, 1.49-22.25, p:0.011) were independent risk factors for anti-HEV IgG positivity in the non-immunosuppressive subgroup consisting of AH and CHC patients. Conclusion: The HEV seroprevalence rate was high (9.9%), despite low viremia rate (0.6%) in high-risk patients. The emergence of HEV3 might indicate a serious problem for these patients. Future investigations are needed to elucidate foodborne transmission routes of HEV in Turkey.