Lack of evidence for the transmission of hepatitis E virus by coagulation factor concentrates based on seroprevalence data

Hepatitis E Virus in Individuals Undergoing Heparin Therapy: An Observational Serological and Molecular Study

INTRODUCTION

Heparin is derived from swine and has been suggested as a possible source of HEV. To study the potential risk of HEV infection associated with heparin treatment, two groups of individuals were compared. Sera from heparinized (N=93) and non-heparinized individuals (N=111) were tested for markers of acute HEV infection and anti-HEV IgG seroprevalence.

METHODS

An acute HEV case was defined by the presence of anti-HEV IgM and/or HEV RNA. From the 93 heparinized individuals, one was positive for IgM and IgG anti-HEV and two were positive for HEV RNA (for both ORF3 and ORF2), and there were a total of two (2.2%) cases of current or recent HEV infection. From the 111 non-heparinized individuals, three were positive for IgM anti-HEV, one was positive for both IgM and IgG anti-HEV, and none was positive for HEV RNA, and there were a total of three (2.7%) cases of current or recent HEV infection. The difference between HEV cases in the heparinized individuals and the non-heparinized individuals was not statistically significant (2.2% vs. 2.7%; p = 0.799).

RESULTS

Concerning IgG anti-HEV, it was detected in 32 individuals from the heparinized group and in 18 from the non-heparinized control group. A statistically significant difference was observed in the presence of anti-HEV IgG in heparinized individuals and controls (p = 0.003).

CONCLUSION

This study has not found any association between heparin treatment and acute HEV infection, but has shown the use of therapeutic heparin as a risk factor for IgG anti-HEV seropositivity.

Higher Risk of HEV Transmission and Exposure among Blood Donors in Europe and Asia in Comparison to North America: A Meta-Analysis

Background and aims: The increasing number of diagnosed hepatitis E virus (HEV) infections in Europe has led to the implementation of the testing of blood products in various countries. Many nations have not yet implemented such screening. To assess the need for HEV screening in blood products worldwide, we conducted a systematic review and meta-analysis assessing HEV RNA positivity and anti-HEV seroprevalence in blood donors. Methods: Studies reporting anti-HEV IgG/IgM or HEV RNA positivity rates among blood donors worldwide were identified via predefined search terms in PubMed and Scopus. Estimates were calculated by pooling study data with multivariable linear mixed-effects metaregression analysis. Results: A total of 157 (14%) of 1144 studies were included in the final analysis. The estimated HEV PCR positivity rate ranged from 0.01 to 0.14% worldwide, with strikingly higher rates in Asia (0.14%) and Europe (0.10%) in comparison to North America (0.01%). In line with this, anti-HEV IgG seroprevalence in North America (13%) was lower than that in Europe (19%). Conclusions: Our data demonstrate large regional differences regarding the risk of HEV exposure and blood-borne HEV transmission. Considering the cost–benefit ratio, this supports blood product screening in high endemic areas, such as Europe and Asia, in contrast to low endemic regions, such as the U.S.

Transfusion-transmitted hepatitis E: What we know so far?

Hepatitis E virus (HEV) is a major cause of viral hepatitis globally. There is growing concern about transfusion-transmitted HEV (TT-HEV) as an emerging global health problem. HEV can potentially result in chronic infection in immunocompromised patients, leading to a higher risk of liver cirrhosis and even death. Between 0.0013% and 0.281% of asymptomatic blood donors around the world have HEV viremia, and 0.27% to 60.5% have anti-HEV immunoglobulin G. HEV is infectious even at very low blood concentrations of the virus. Immunosuppressed patients who develop persistent hepatitis E infection should have their immunosuppressant regimen reduced; ribavirin may be considered as treatment. Pegylated interferon can be considered in those who are refractory or intolerant to ribavirin. Sofosbuvir, a nucleotide analog, showed modest antiviral activity in some clinical studies but sustained viral response was not achieved. Therefore, rescue treatment remains an unmet need. The need for HEV screening of all blood donations remains controversial. Universal screening has been adopted in some countries after consideration of risk and resource availability. Various pathogen reduction methods have also been proposed to reduce the risk of TT-HEV. Future studies are needed to define the incidence of transmission through transfusion, their clinical features, outcomes and prognosis.