Seroepidemiology of hepatitis E virus infection among preschool children in Taiwan

A systematic review of hepatitis E virus infection in children

A systematic review was conducted, seeking all literature relevant to the epidemiology, clinical and laboratory features, and outcome of hepatitis E virus (HEV) infection in children. Transmission is thought to be primarily from fecal-oral transmission, with the role of transmission from animal reservoirs not being clear in children. Worldwide, seroprevalence is <10% up to 10 years of age, with the exception of 1 of 5 studies from India and the sole study from Egypt. Seroprevalence increases with age, but it is not clear if it is increasing over time. The clinical presentation of HEV infection has broad similarities to hepatitis A virus (HAV) infection, with most cases being subclinical. However, HEV differs from HAV in that infectivity is lower, perinatal transmission can result in neonatal morbidity and even mortality, and a chronic carrier state exists, accounting for chronic hepatitis in some pediatric solid organ transplant recipients.

Light and Darkness: Prevalence of Hepatitis E Virus Infection among the General Population

Human hepatitis E virus (HHEV) spreads early in life among the population in areas endemic for genotype 1 and infects mainly adults in areas endemic for genotype 3, where it would be responsible for about 10% of cases of suspected acute viral hepatitis of unknown etiology and for a number of subclinical, unrecognized infections. The overall prevalence of antibody to HHEV is high in most of the former areas and low in most of the later ones, but wide regional differences have been recorded in both cases. "Hot spots" of HHEV infection would exist for both types of strains in particular regions or among particular populations of the world. Studies on pork derivatives, shellfish bivalves, and vegetables for HHEV contamination at the sale point need to be extended for evaluating the impact of the agent on food safety, and the meaning of the finding of HHEV genotype 1 genomes in urban sewage from developed countries should be established through active surveillance. Consensus about technical issues in regard to anti-HEV testing would improve the knowledge of the HHEV epidemiology. Studies in particular regions and populations, and introduction of molecular diagnosis in the clinical setting as a routine tool, would also be required.

The epidemiology of hepatitis E virus infections in developed countries and among immunocompromised patients

Hepatitis E virus (HEV) is an important cause of acute hepatitis in humans worldwide, both as epidemic and sporadic disease. Since the virus was identified in 1983, epidemics have occurred regularly in many countries across South and Southeast Asia when seasonal floods have contaminated drinking water supplies and in Africa during humanitarian crises among refugee populations without access to clean water. In addition, sporadic cases and small clusters of HEV infections have been recognized throughout the world in developed countries over the past couple of decades. This review will focus on emerging evidence of HEV infection as an under-recognized pathogen in Europe, the USA and other industrialized countries. We will discuss some of the issues associated with the recognition, diagnosis and treatment of these sporadic cases. We will also summarize the recent literature on autochthonous HEV infection among populations in developed countries in industrialized Europe, the USA, Japan and other industrialized Asian countries. We will review recent reports of acute and chronic HEV infections among transplant recipients and other immunocompromised individuals including HIV/AIDS patients.

HBV infection in indigenous children, 20 years after immunization in Taiwan: a community-based study

OBJECTIVES

Hepatitis B virus infection is hyperendemic in Taiwan. In the past, the infection rate has been higher in indigenous villages. The prevalence of chronic HBV infection among indigenous children after immunization remains unknown.

METHODS

A total of 843 indigenous children were checked for the hepatitis B seromarker. Another 606 metropolitan children were enrolled for comparison in 2005.

RESULTS

The seroprevalences (%) of HBsAg, (hepatitis B surface antigen) anti-HBs, (antibody to hepatitis B surface antigen) and anti-HBc (antibody to hepatitis B core antigen) among indigenous and metropolitan children were 3.2 vs. 0.17 (p<0.001), 47.4 vs. 51.2 (p=0.164), and 10.7 vs. 1.7 (p<0.001), respectively. Among the indigenous children, who were divided into three age groups, the prevalences of HBsAg and anti-HBc increased with age, while anti-HBs decreased significantly (p=0.025, 0.002, and <0.001, respectively). Children with positive HBsAg had a significantly higher mean (SD) age (10.2 (2.2) vs. 9.2 (2.1) years, p=0.024) and a higher ALT value (16.4 (8.0) vs. 10.6 (8.3) IU/L, p=0.001). In a multivariable analysis, indigenous residency, older age group and abnormal ALT value were independent factors associated with positive HBsAg.

CONCLUSIONS

The seroprevalence of hepatitis B infection has obviously declined among indigenous children 20 years after mass immunization programs launched in Taiwan. However, it is still higher than that of metropolitan children. Higher rates of chronic HBV infection in the mothers might be one important explanation for this finding.

Hepatitis E virus in Isfahan Province: a population-based study

INTRODUCTION

Hepatitis E virus (HEV) is an enterically transmitted acute viral hepatitis with the highest incidence in Asia, Africa, the Middle East, and Central America. There are few published data on the epidemiology of the infection in Iran. Hence, this study was carried out to evaluate anti-HEV seroprevalence in Isfahan Province, Iran.

METHODS

In 2005, a cross-sectional study of 816 subjects over 6 years of age from urban and rural areas of Isfahan Province, selected using the multistage cluster sampling method, was undertaken. Demographic data and blood samples were collected, and anti-HEV antibodies were measured by ELISA method. The Chi-square test was used for statistical analysis and p<0.05 was considered significant.

RESULTS

Of the study subjects, 428 were female (52.5%) and 388 were male (47.5%). The overall anti-HEV seroprevalence rate was 3.8%. There was no significant difference in HEV seropositivity between the subjects grouped according to gender (4.2% in females and 3.4% in males, p=0.78), household number (p=0.95), and area of residence (2.7% in rural and 4.1% in urban areas, p=0.09). HEV seroprevalence increased with age from 0.9% in children aged 6-9 years to 8.1% in persons over 50 years old, without statistical differences (p=0.08). There were statistical differences in HEV seropositivity in the different regions of Isfahan Province, with the highest prevalence seen in Khomeini Shahr (13.3%; p<0.001).

CONCLUSION

HEV seroprevalence in Isfahan Province is lower than that previously reported in other parts of Iran and the Middle East area. More studies in other parts of Iran are needed to obtain a prevalence map for creating preventional strategies.

Prevalence of hepatitis E virus infection in children in the northeast of Spain

The prevalence of immunoglobulin G (IgG) anti-hepatitis E virus (anti-HEV) antibodies was studied with a representative sample of 1,249 healthy children aged between 6 and 15 years. IgG anti-HEV antibodies were detected in 57 (4.6%) of the 1,249 samples analyzed, suggesting that some children are exposed to HEV in early childhood.

Seroprevalence of hepatitis E virus infection among institutionalized psychiatric patients in Taiwan

BACKGROUND

Hepatitis E virus infection (HEV) remains unclear in institutionalized psychiatric patients.

OBJECTIVES

To investigate the prevalence and risk factors of HEV infection in a psychiatric institution in Taiwan.

STUDY DESIGN

A total of 754 patients with psychiatric disorders were enrolled in the study. Clinical features, review of patient charts, and interviews with families were recorded for analysis. Antibody to HEV was tested using a commercial enzyme-linked immunosorbent assays.

RESULTS

The prevalence of HEV infection in institutionalized patients was as high as 14.5%. Males had higher prevalence than females. It was also found prevalence increased significantly by age group. When compared with patients 30 years old or less, those in the 31-40 year old age group had an odds ratio of 4.89 [95% confidence interval (CI), 1.15-20.82], 41-50 years old of 6.30 (95% CI, 1.48-26.83), and 50 years or older of 6.20 (95% CI, 1.44-26.74). In multivariate logistic regression analysis, age and male gender were the independent risk factors.

CONCLUSIONS

Institutionalized psychiatric patients had higher prevalence of HEV infection. In addition, there was an age-related increase in exposure to HEV with males that had a higher HEV seropositivity.

Seroepidemiology of hepatitis A, B, C, and E viruses infection among preschool children in Taiwan

Taiwan was a hyperendemic area for hepatitis A and B viruses (HAV and HBV) infection before late 1980s. To study the seroprevalence of hepatitis A, B, C, and E viruses (HCV and HEV) infection among preschool children in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and 2 aboriginal areas randomly selected through stratified sampling. Serum specimens of 2,538 preschool children were screened for the hepatitis A, C, and E antibodies by a commercially available enzyme immunoassay and for HBV markers by radioimmunoassay methods. The multivariate-adjusted odd ratios (OR) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. Females had a statistically significantly higher HAV seroprevalence than males. The seroprevalence of HCV infection increased significantly with age. The larger the sibship size, the higher the seroprevalence of HBV infection. Aboriginal children had a significantly higher seroprevalence of HBV and HEV infection and lower seroprevalence of HCV infection than non-aboriginal children. A significantly higher seroprevalence of HBV infection was found in rural children than urban children. There was no significant association between serostatus of HAV and HEV infection and between serostatus of HBV and HCV infection among preschool children in Taiwan. The poor environmental and hygienic conditions in the aboriginal areas might play a role in infection with HBV and HEV.

Etiological investigation of fatal liver failure during the course of chronic hepatitis B in southeast China

BACKGROUND

The purpose of this study was to clarify the relationships between patients who had fatal liver failure during the course of chronic hepatitis B and those who were also superinfected with hepatitis A, C, D, or E virus, as well as their hepatitis B virus e system status, so that suitable measures could be adopted to decrease the mortality of patients with chronic hepatitis B.

METHODS

This study detected superinfections of hepatitis A, C, D, or E virus and the hepatitis B virus e system status in cases of fatal liver failure during the course of chronic hepatitis B by enzyme-lined immunosorbent assay.

RESULTS

The frequency of superinfections of hepatitis A, C, D, and E virus was 1.4% (4/282), 6.4% (18/282), 1.8% (5/282), and 28.4% (80/282), respectively, overall, 37.9% (107/282). Hepatitis E was prominent and steady in superinfection rates during the past 12 years. In 62.1% (175/282) of patients, the causes of fatal liver failure were not clear. The serological status frequency of HBeAg(+) and anti-HBe(-), HBeAg(-) and anti-HBe(-), and HBeAg(-) and anti-HBe(+) was 20.6% (22/107), 23.4% (25/107), and 56.1% (60/107), respectively, in the group with superinfections of hepatitis A, C, D, or E virus and 31.4% (55/175), 21.1% (37/175), and 47.4% (83/175), respectively, in the group in which causes were not clear. The serological status HBeAg(+) and anti-HBe(-) was more frequent in the group in which causes were not clear than in the group with superinfections of hepatitis A, C, D, or E virus (P < 0.05). Statistically, there were no differences (P > 0.05) between the serological status HBeAg(-), anti-HBe(-) and HBeAg(-), anti-HBe(+) between the two groups.

CONCLUSIONS

These results suggest that superinfection (107/282) is an important factor in fatal liver failure. The mortality of chronic hepatitis B can be decreased by strict food sanitation and the use of safe blood products. There were no significant relationships between hepatitis B e antigen seroconversion and fatal liver failure during the course of chronic hepatitis B.