Seroepidemiologic study of hepatitis E virus infection in pregnant women in Xiamen

Abstract

Objective To investigate the seroprevalence and epidemiological characteristics of hepatitis E virus (HEV) infection in pregnant women in Xiamen. Methods Sera samples of 910 pregnant women were collected from September 2014 to June 2015 in Xiamen Huli District Maternity and Child Care Hospital. Those who intended to give birth in target hospital were included in a subgroup which was asked to collect the second serum sample. All samples were tested for anti-HEV IgM and IgG antibody by enzyme linked immunosorbent assay (ELISA). HEV RNA was tested by reverse transcription-polymerase chain reaction (RT-PCR) for the positive samples of anti-HEV IgM antibody, meanwhile, the quantitative detections for anti-HEV IgG were conducted in specimens positive for anti-HEV IgG. Results Of the 910 pregnant women, 8 (0.88%, 95%CI 0.45%-1.73%) were anti-HEV IgM positive. HEV RNA was found in 3 cases through RT-PCR and viral load values were between 600 and 700 copies/ml; 140 (15.38%, 95%CI 13.19%-17.68%) were anti-HEV IgG positive and geometric mean concentration of the samples was 0.385 Wu/mL (95%CI 0.332-0.445 Wu/ml). The positive rate of anti-HEV IgG increased with age (P=0.004). In the subgroup, 150 pregnant women were included and followed up, 4 of those were defined as 'new HEV infection cases’ and the incidence was evaluated as 10.7/100 person-year (95%CI 3.39-25.7/100 person-year). Conclusions There were a low percentage of HEV carriers in pregnant women in Xiamen, but the risk of new primary infection in pregnant women during pregnancy was much higher than the general population, suggesting that it is necessary to expand sample size to clarify the burden of HEV infection during pregnancy. Key words: Hepatitis E virus; Pregnant women; Seroprevalence; New infection