An assessment of hepatitis E virus (HEV) in US blood donors and recipients: no detectable HEV RNA in 1939 donors tested and no evidence for HEV transmission to 362 prospectively followed recipients

Abstract

Background: Hepatitis E virus (HEV) infection has become relevant to blood transfusion practice because isolated cases of blood transmission have been reported and because HEV has been found to cause chronic infection and severe liver disease in immunocompromised patients.

Study design and methods: We tested for immunoglobulin (Ig)G and IgM antibodies to the HEV and for HEV RNA in 1939 unselected volunteer US blood donors. Subsequently, we tested the same variables in pre- and serial posttransfusion samples from 362 prospectively followed blood recipients to assess transfusion risk.

Results: IgG anti-HEV seroprevalence in the total 1939 donations was 18.8%: 916 of these donations were made in 2006 at which time the seroprevalence was 21.8% and the remaining 1023 donations were in 2012 when the seroprevalence had decreased to 16.0% (p < 0.01). A significant (p < 0.001) stepwise increase in anti-HEV seroprevalence was seen with increasing age. Eight of 1939 donations (0.4%) tested anti-HEV IgM positive; no donation was HEV RNA positive. Two recipients had an apparent anti-HEV seroconversion, but temporal relationships and linked donor testing showed that these were not transfusion-transmitted HEV infections.

Conclusion: No transfusion-transmitted HEV infections were observed in 362 prospectively followed blood recipients despite an anti-HEV seroprevalence among donations exceeding 16%.

Figure 1

Distribution of sample/cut off ratios for hepatitis E virus IgG in positive and negative samples from 1939 NIH volunteer blood donors.

Figure 2

Prevalence of anti-hepatitis E virus (HEV) IgG in 916 NIH volunteer blood donors by age group.

Figure 3. Suspected, but unconfirmed anti-HEV IgG seroconversion in two blood recipients

Recipient 1 received one HEV RNA⁺ and one high titer anti-HEV IgG⁺ blood unit 4 days before the sample collected at 36 weeks after the index study transfusion. The patient died shortly after receiving the HEV RNA⁺ unit and thus the consequences of that transfusion could not be assessed. Recipient 2 could be interpreted as having a very early seroconversion post-transfusion, but more likely was infected prior to the index transfusion based on the timing and on the pre-transfusion sample having a relatively high, albeit below cut-off.