Low Prevalence of HEV Infection and No Associated Risk of HEV Transmission from Mother to Child among Pregnant Women in Vietnam.

Pham Xuan Huy,Hoang Van Tong,C-Thomas Bock,Le Minh Dung,Srinivas Reddy Pallerla,Bui Tien Sy,Peter G Kremsner,Ngo Thu Hang,Dang Thanh Chung,Heiner Wedemeyer,Dang Thuy Linh,Thirumalaisamy P Velavan,Sivaramakrishna Rachakonda,Nguyen Linh Toan,Le Thi Kieu Linh,Can Van Mao,Le Huu Song

doi:10.3390/pathogens10101340

Abstract

Infections with HEV in low- and middle-income countries (LMICs) are associated with increased rates of preterm birth, miscarriage, and stillbirth. The aim of the present study was to investigate HEV infections in pregnant women and the possibility of mother-to-child transmission, and associated outcomes. A total of 183 pregnant women in their third trimester were recruited and followed until delivery. Anti-HEV IgG and IgM were determined via enzyme-linked immunosorbent assay (ELISA), and HEV nucleic acids were detected in stool and cord blood samples. HEV genotypes were identified by Sanger sequencing, and phylogenetic analyses were performed. Mother-to-child transmission and associated adverse outcomes were not observed. Only 2% of patients (n = 4/183) tested positive for anti-HEV IgM, and 8% (n = 14/183) tested positive for anti-HEV IgG antibodies. Cord blood (n = 150) analysis showed that there was no IgM detected, while 4% (n = 6/150) tested positive for anti-HEV IgG, which was consistent with mothers testing positive for anti-HEV IgG. Nucleic acid tests for HEV RNA yielded 2% (n = 4/183) from the serum and stool of pregnant women, and none from cord blood. The HEV isolates belonged to the genotype HEV-3a, with 99% homology with humans and 96% with pigs. No association was found between the risk of HEV infection and pregnancy outcomes or HEV transmission from mother to child. HEV-3 infections of zoonotic origin in pregnancy might have eventually resolved without complications.

Highlights

The hepatitis E virus (HEV) is a common cause of acute viral hepatitis worldwide, with an estimated 20 million HEV infections, 3.4 million symptomatic infections, 70,000 deaths, and 3000 stillbirths per year [1]
Though the disease is usually a mild and self-limiting form of acute hepatitis, pregnant women in endemic countries are at particular risk of severe disease, as pregnant women infected with HEV genotype 1 (HEV-1) in the third trimester are at high risk, with relative mortality and morbidity of ~15–60% [2]
In Vietnam— a country where HEV and hepatitis B virus (HBV) infections are endemic—pregnant women are at high risk of HEV infection, which is often caused by HEV genotype 1 (HEV-1)

Summary

Introduction

The hepatitis E virus (HEV) is a common cause of acute viral hepatitis worldwide, with an estimated 20 million HEV infections, 3.4 million symptomatic infections, 70,000 deaths, and 3000 stillbirths per year [1]. Major outbreaks of HEV infection were reported from Asia and South-East Asia [1]. The clinical complications of HEV often include acute liver failure, bleeding, and eclampsia gravidarum. The mechanism of predilection in pregnant women is not understood, and attributed causes include fulminant liver failure and obstetric complications such as eclampsia and hemorrhage [5,6,7]. Acute and chronic HEV genotype 3 (HEV-3) infections (zoonotic origin) have been reported in pregnant women, but the infections eventually resolve without complications

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