Epidemiological study of hepatitis E virus infection among students and workers in Hebei Province of China.

AIMS: Hepatitis E caused by the hepatitis E virus (HEV) is prevalent worldwide. In China, considerable shifts in the epidemiology of hepatitis E have been observed over the last two decades, with ongoing changes in the prevalence of HEV. METHODS: This study, in conjunction with the health examinations for students and workers, aims to estimate the seroprevalence and assess the risk factors of HEV infection in general population in Hebei province, China. Epidemiological information was collected using a specific questionnaire and blood samples were collected from each participant during the process of health examination. Anti-HEV IgG and IgM in sera were tested using the Wantai ELISA assay kits. Logistic regression modelling was used to identify associated risk factors. RESULTS: The average positive rate of anti-HEV IgG in students (6-25 years) was 3.4%. One (0.2%) student was anti-HEV IgM positive, while also testing positive for IgG. The HEV seroprevalence was not related to students' gender, school, or family residence. In occupational populations, the overall seropositivity rate was 13.3% for anti-HEV IgG and 0.67% for IgM. HEV seropositivity increased significantly with age, ranging from 3.8% to 18.6% in age groups, and differed significantly among four occupation groups: farmers (17.6%), food supply workers (18.0%), other non-farm workers (14.7%) and healthcare workers (5.9%) (p = 0.002). Multivariable logistic analysis confirmed the significant correlations of seroprevalence with age and occupation. CONCLUSIONS: The study found a low seroprevalence of HEV in children and young adults in Hebei Province, China. Advanced age correlates with higher seroprevalence in occupational populations, indicating an accumulation of HEV infection over time. Seroprevalence varied significantly among different occupation groups, suggesting the important role of occupational exposure for HEV infection.

High seroprevalence of hepatitis E virus in rabbit slaughterhouse workers.

Hepatitis E virus (HEV) was first detected in rabbits in the year 2009. Rabbit HEV is now known to be widely prevalent in rabbits and tentatively assigned into genotype 3 (HEV-3) as subgenotype-3ra (HEV-3ra). However, its role in human infection remains undetermined. This study was conducted to investigate the prevalence of HEV infection among rabbit slaughterhouse workers and to identify whether the workers exposed to rabbits are at a higher risk of HEV infection. Seventy-five workers at rabbit slaughterhouses and a control group of 421 general adults in the same area in Hebei province, China, were serologically examined for anti-HEV antibodies. HEV seroprevalences between the slaughterhouse workers and the general adults were compared. Age-adjusted prevalence of anti-HEV immunoglobulin G (IgG) in the rabbit slaughterhouse workers and control group was 46.1% and 10.8% respectively. The slaughterhouse workers had significantly higher seroprevalence and an approximately 6.9-fold increased risk for being seropositive for anti-HEV IgG as compared to the general population (odds ratio, 6.9; 95% CI: 4.3, 10.9). In slaughterhouse workers, anti-HEV IgG positive rate was positively associated with working years; in general adults, this rate was positively associated with age. The prevalence of anti-HEV immunoglobulin M (IgM) among exposed workers (6.7%) was significantly higher than that of control groups (1.2%). In conclusion, the seroprevalence of HEV is significantly higher in slaughterhouse workers than in general adults indicating that occupational exposure to rabbits is a potential risk factor for HEV infection.

Detection and assessment of infectivity of hepatitis E virus in urine.

BACKGROUND & AIMS: Hepatitis E virus (HEV) is known to be excreted in the stool but there has been no report of its presence in urine. This study investigated the presence of HEV RNA and antigen (HEV-Ag) in urine and its possible transmission. METHODS: Serum and urine samples from patients with chronic or acute HEV infection and HEV infected monkeys were tested for viral and biochemical markers. Liver and kidney biopsies from the infected monkeys were analyzed by histopathology and immunohistochemistry. The infectivity of HEV from urine was assessed by inoculation into monkeys. RESULTS: HEV RNA and HEV-Ag were detected persistently in the urine of a patient with chronic HEV infection. Subsequently, HEV RNA was detected in the urine of three of the eight (37.5%) acute patients, all of whom had detectable HEV-Ag in their urine. HEV RNA and HEV-Ag were also detectable in the urine of HEV infected monkeys. The ratio of HEV-Ag to RNA in the urine of the infected monkeys was significantly higher than in their sera and feces. The parameters of routine urinalysis remained within the normal ranges in the hepatitis E patients and infected monkeys, however, pathological changes and HEV-Ag were observed in the kidneys of the infected monkeys. Furthermore, one of two monkeys became infected with HEV after inoculation with urine from another infected monkey. CONCLUSIONS: HEV infection may result in kidney injury and the urine may pose a risk of transmission. HEV-Ag detection in urine may be valuable for diagnosis of ongoing HEV infection.

Persistent hepatitis e virus genotype 4 infection in a child with acute lymphoblastic leukemia.

INTRODUCTION: In general, the hepatitis E virus (HEV) causes acute, self-limiting hepatitis. Prolonged and chronic infections caused by HEV genotype 3 have been found in some immunosuppressed patients in developed countries. CASE PRESENTATION: Here we report a Chinese boy with acute lymphoblastic leukemia, who developed hepatitis E during a period of intensive chemotherapy. Twenty months after the initial infection, HEV viremia was reappeared in the patient, with detectable anti-HEV IgM and IgG and modestly elevated serum transaminases. Sequence analysis of the viral RNAs revealed the reactivation of the HEV genotype 4d strain, indicating viral persistence in the patient. CONCLUSIONS: To our knowledge, this is the first chronic case confirmed by the prolonged presence of HEV RNA in china. It is also the first reported persistent hepatitis E infection caused by HEV genotype 4.

Genotype analysis of hepatitis E virus from sporadic hepatitis E cases in northern China.

Hepatitis E is an important public health problem in many countries. However, there is no definite conclusion about the zoonotic reservoir, transmission patterns and risk factors of hepatitis E in the human population. The aim of this study was to analyze the epidemiological and viral genotype characteristics of hepatitis E cases in northern China. Surveillance was conducted in two hospitals in Liaoning and Hebei province from July 2010 to June 2012. Out of a total of 116 diagnosed patients, 88 (75.9%) were male and 28 (24.1%) were female and most (73%) were in the age group 40-70 years. In both hospitals, cases were diagnosed more frequently in March than in other months. HEV RNA was amplified from 41 patients and characterized by nucleotide sequencing and phylogenetic analysis. Most of the isolates (37 strains, 90.3%) were genotype 4, including subgenotypes 4a, 4b, 4d, 4h, 4i and a new subgenotype. One subgenotype 3a strain was isolated from Baoding, Hebei province. Three genotype 1b strains were found from patients in Jinzhou, Liaoning province. Most of the genotype 4 strains and the genotype 3 strains were phylogenetically related to known swine isolates. In conclusion, the finding that HEV infects mostly middle-aged and elderly men and that the incidence spiked in March may reflect the zoonotic transmission characteristics of HEV infection. Pigs, but not rabbits, were the important reservoirs in this area, because genotype 4 HEV was found to be responsible for the majority hepatitis E cases. However, genotype 1 is still present in northern China. Also, the first isolation of genotype 3 HEV in this area indicates that alternative routes of HEV transmission might exist.