Hepatitis E virus infection in the Irish blood donor population

BACKGROUND: Hepatitis E virus (HEV) Genotype 3 (G3) infection is a zoonosis that may be transmitted during the acute phase by transfusion. The aim of this study was to determine the incidence of HEV and seroprevalence among Irish blood donors. STUDY DESIGN AND METHODS: Anonymized samples from 1076 donations collected in 2012 were tested for HEV immunoglobulin (Ig)G using the Wantai enzyme-linked immunosorbent assay. A total of 24,985 anonymized donations collected between December 2013 and June 2014 were individually tested for HEV RNA using the Procleix HEV assay; reactive donations were confirmed by an in-house real-time polymerase chain reaction (PCR) test. RESULTS: Seroprevalence for anti-IgG was 5.3% (95% confidence interval [CI], 4.0%-6.8%), ranging from 1.1% in the 18- to 29-years age group to 33.3% in males over 60 years. HEV RNA screening of 24,985 samples yielded five PCR-confirmed donations (1:4997, 0.02%; 95% CI, 0.0065%-0.0467%), only one of which was serologically reactive (HEV IgM reactive only). Viral loads ranged from 10 to 44,550 IU/mL. Genotype analysis on three samples identified HEV G3 virus. Four of the five viremic donations were from donors in the 18- to 29-years age group (p = 0.01). CONCLUSION: Seroprevalence for anti-HEV IgG was low compared to some European countries, but 1 in 5000 donations was viremic. Viremia was predominantly in younger Irish donors. After Department of Health approval the Irish Blood Transfusion Service implemented individual blood donation HEV RNA screening initially for a 3-year period from January 2016.