Aim: To address the issue of whether or not hepatitis E virus (HEV) is transmitted parenterally.
Methods: We conducted a retrospective study which involved 145 multiple transfused patients and 250 healthy controls. A prospective study was also undertaken involving 50 hospitalized patients, 25 of whom were transfused with 107 blood units, while the other 25 did not receive any transfusions.
Results: In our retrospective study, markers of acute HEV infection (IgM anti-HEV and HEV RNA) were detected in a significantly higher number of multiple transfused patients (13 of 145) compared to controls (two of 250) (P < 0.001; OR = 12.21 [95% confidence interval: 2.71–54.70]). All 13 HEV-infected patients had been transfused at least once in a 3-month period before testing. Overall, patients positive for any of the HEV markers (IgG, IgM or HEV RNA) had received more blood transfusions, had higher occurrence of icteric disease and higher serum alanine aminotransferase levels. In our prospective study, IgG anti-HEV was detected in 11 of 107 donor samples, three of 25 patients in their pretransfusion samples (one sample was positive for IgM anti-HEV as well) and two of 25 control patients. Post-transfusion HEV infection developed in three of 22 susceptible (IgG anti-HEV negative) transfused patients; the infection was traced to their four respective donors who were asymptomatic, HEV RNA positive (4/4) and IgM anti-HEV positive (3/4). In contrast, none of the non-transfused patients developed HEV infection during the follow-up period.
Conclusion: Frequent transmission of HEV by blood transfusion places recipients at risk and warrants redefining of the donor screening policy by blood banks, especially in endemic areas.