Acute, Recent and Past HEV Infection among Voluntary Blood Donors in China: A Systematic Review and Meta-Analysis

Prevalence of hepatitis E virus in China from 1997 to 2022: a systematic review and meta-analysis

Introduction

Several studies have reported on hepatitis E virus (HEV) prevalence in various regions of China, but the results vary widely. Herein, we conducted a systematic review and meta-analysis to assess the seroprevalence, RNA-positive rate, genotype distribution of HEV in China, and its risk factors.

Methods

We included 208 related studies involving 1,785,569 participants published between 1997 and 2022. Random-effects models were used to pool prevalence, and subgroup analyses were conducted by population, gender, age, study period, regions, and rural-urban distribution. The meta regression models and pooled odds ratios (OR) were performed to identify risk factors for HEV infections.

Results

The pooled anti-HEV IgG, IgM, and Ag seroprevalence, and RNA detection rates in China from 1997 to 2022 were 23.17% [95% confidence interval (CI): 20.23-26.25], 0.73% (95% CI: 0.55-0.93), 0.12% (95% CI: 0.01-0.32), and 6.55% (95% CI: 3.46-12.05), respectively. The anti-HEV IgG seropositivity was higher in the occupational population (48.41%; 95% CI: 40.02-56.85) and older adult aged 50-59 years (40.87%; 95% CI: 31.95-50.11). The dominant genotype (GT) of hepatitis E in China was GT4. Notably, drinking non-tap water (OR = 1.82; 95% CI: 1.50-2.20), consumption of raw or undercooked meat (OR = 1.47; 95% CI: 1.17-1.84), and ethnic minorities (OR = 1.50; 95% CI: 1.29-1.73) were risk factors of anti-HEV IgG seroprevalence.

Discussions

Overall, the prevalence of hepatitis E was relatively high in China, especially among older adults, ethnic minorities, and humans with occupational exposure to pigs. Thus, there is a need for preventive measures, including HEV infection screening and surveillance, health education, and hepatitis E vaccine intervention in high-risk areas and populations.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023397036.

Development and clinical validation of a one-step pentaplex real-time reverse transcription PCR assay for detection of hepatitis virus B, C, E, Treponema pallidum, and a human housekeeping gene

BACKGROUND

With the safety of blood transfusion being a major public health concern, the development of a rapid, sensitive, specific, and cost-effective multiplex PCR assay for simultaneous detection of hepatitis B virus(HBV), hepatitis C virus (HCV), hepatitis E virus (HEV), and Treponema pallidum(T. pallidum) in blood is crucial.

METHODS

Five primer pairs and probes were designed towards conserved regions of target genes and used to establish a one-step pentaplex real-time reverse transcription PCR(qRT-PCR) assay for simultaneous detection of HBV, HCV, HEV, T. pallidum, and RNase P(housekeeping gene), providing sample quality check. The clinical performance of the assay was further determined with 2400 blood samples from blood donors and patients in Zhejiang province, and compared the results with commercial singleplex qPCR and serological assays.

RESULTS

The 95% limit of detection(LOD) of HBV, HCV, HEV, and T. pallidum were 7.11 copies/µL, 7.65 copies/µL, 8.45 copies/µL, and 9.06 copies/µL, respectively. Moreover, the assay has good specificity and precision. Compared to the singleplex qPCR assay, the novel assay for detecting HBV, HCV, HEV, and T. pallidum presented 100% clinical sensitivity, specificity, and consistency. Several discrepant results between serological and pentaplex qRT-PCR assays were found. Of 2400 blood samples, there were 2(0.08%) HBsAg positive samples, 3(0.13%) anti-HCV positive samples, 29(1.21%) IgM anti-HEV positive samples and 6(0.25%) anti-T. pallidum positive samples proven negative in nucleic acid detection. 1(0.04%) HBV DNA positive sample and 1(0.04%) HEV RNA positive sample were detected negative by serological testing.

CONCLUSIONS

The developed pentaplex qRT-PCR is the first assay on simultaneous, sensitive, specific, and reproducible detection of HBV, HCV, HEV, T. pallidum, and RNase P in a single tube. It could detect pathogens in blood during the window period of infection and is a good tool for effectively screening blood donors and early clinical diagnosis.

Hepatitis E virus infection in the United States: Seroprevalence, risk factors and the influence of immunological assays

In the United States (U.S.), a hepatitis E virus (HEV) seroprevalence between 6 and 21% has been described, with a decreasing trend. We aimed to investigate HEV infection in the U.S. population from 2009 to 2016, and examine the differences in seroprevalence using different assays. We used data from the National Health and Nutrition Examination Survey (NHANES-CDC) to estimate HEV seroprevalence and analyze demographic variables related to the infection. Additionally, we compared 4 serological tests used. The estimated HEV seroprevalence between 2009-2016 was 6.1% (95% CI: 5.6%-7.0%) for IgG and 1.02% (0.8%-1.2%) for IgM. Higher HEV IgG prevalences were found in older people, females, non-Hispanic Asians and those born outside of the U.S. The in-house immunoassay and the Wantai HEV-IgG ELISA presented the highest sensitivity values in the tested population. The highest specificity values corresponded to the DSI-EIA-ANTI-HEV-IgG assay. The kappa statistical values showed concordances no greater than 0.64 between the assays. HEV prevalence in our study was similar to previously reported, and a decline in the prevalence was observed through the NHANES assessments (from 1988 to 2016). The sensitivity and specificity of the assays varied widely, making comparisons difficult and highlighting the need to develop a gold standard assay.

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.

Hepatitis E Virus Infection-Immune Responses to an Underestimated Global Threat

Infection with the hepatitis E virus (HEV) is one of the main ubiquitous causes for developing an acute hepatitis. Moreover, chronification plays a predominant role in immunocompromised patients such as transplant recipients with more frequent severe courses. Unfortunately, besides reduction of immunosuppression and off-label use of ribavirin or pegylated interferon alfa, there is currently no specific anti-viral treatment to prevent disease progression. So far, research on involved immune mechanisms induced by HEV is limited. It is very difficult to collect clinical samples especially from the early phase of infection since this is often asymptomatic. Nevertheless, it is certain that the outcome of HEV-infected patients correlates with the strength of the proceeding immune response. Several lymphoid cells have been identified in contributing either to disease progression or achieving sustained virologic response. In particular, a sufficient immune control by both CD4⁺ and CD8⁺ T cells is necessary to prevent chronic viral replication. Especially the mechanisms underlying fulminant courses are poorly understood. However, liver biopsies indicate the involvement of cytotoxic T cells in liver damage. In this review, we aimed to highlight different parts of the lymphoid immune response against HEV and point out questions that remain unanswered regarding this underestimated global threat.

Hepatitis E virus prevalence among blood donors in Dali, China

BACKGROUND

Hepatitis E virus (HEV) is a nonenveloped RNA virus causing hepatitis E worldwide. The increase in transfusion-transmitted cases of HEV infections from asymptomatic blood donors causing serious illnesses among immunosuppressed recipients has been reported in the past few years. China is one of the most prevalent regions of HEV; as a result, it is important to evaluate the risk of transfusion-transmitted HEV.

METHODS

A total of 1864 serum samples (including demographic characteristics) from blood donors were randomly collected from February to March 2018 in Dali city. Anti-HEV IgG, IgM and IgA antibodies and HEV antigen were examined by enzyme-linked immunosorbent assay (ELISA). HEV RNA was detected by real-time PCR. Multivariable logistic regression modelling was used to examine the risk factors associated with HEV prevalence.

RESULTS

Overall, the positive rates of anti-HEV IgG, IgM, and IgA antibodies were 13.36% (249/1864), 1.13% (21/1864), and 1.82% (34/1864), respectively. However, none of the 1864 serum samples were HEV antigen positive or HEV RNA positive. Females (16.69%) had a significantly higher HEV seroprevalence than males (13.04%) (odds ratio [OR] 1.34 [95% CI, 1.02-1.75]). Bai (18.85%) donors had a significantly higher HEV seroprevalence than Han (12.21%) blood donors (odds ratio [OR], 1.65 [95% CI, 1.24-2.19] for Bai).

CONCLUSIONS

HEV showed a seroprevalence among blood donors in Yunnan Province, some of which were even recent infections, indicating a threat to the safety of blood transfusions. Whether to formulate a strategy for HEV screening in blood centres needs further research.

HEV prevalence and potential risk factors in a large multi-ethnic youth cohort in China

BACKGROUND

This cohort study was designed to investigate the prevalence of and potential risk factors of HEV infection in a large multi-ethnic youth cohort in China.

METHODS

Blood samples were collected from participants (n = 6269) and serum was isolated. All serum samples were tested for anti-HEV IgG, anti-HEV IgM antibodies using commercial enzyme immunoassay kits (Wantai Biological Pharmacy Enterprise, Beijing, China).

RESULTS

The overall rate of anti-HEV IgG and anti-HEV IgM prevalence was 4.78% and 0.14%, 0.03% were positive for both anti-HEV IgG and anti-HEV IgM antibodies. Anti-HEV IgG positivity is significantly higher in females (5.27%) compared to males (4.14%) (P = 0.028). Anti-HEV IgG prevalence is significantly (P = 0.0001) higher in Dong (17.57%), Miao (12.23%), Yi (11.04%), Gelao (9.76%), and Bai (10.00%) compared to other ethnic groups. It is significantly higher in Guizhou (11.4%), Sichuan (10.1%), Yunnan (9.3%), and Guangxi (6.9%) than that other province. We found that ethnicity and provincial background are significantly associated with HEV infection in this cohort.

CONCLUSION

This study provides comprehensive information on HEV prevalence in multi-ethnic populations in China. However, our study only focused on a youth population from different provinces of China. Future studies are recommended to investigate HEV prevalence in other age groups of the ethnic populations.

Hepatitis E virus and blood transfusion safety

While the majority of worldwide hepatitis E viral (HEV) infections that occur in people are from contaminated water or food sources, there has also been a steadily rising number of reported cases of transfusion-transmitted HEV (TT-HEV) in blood donation recipients. For most, HEV infection is acute, self-limiting and asymptomatic. However, patients that are immunocompromised, especially transplant patients, are at much higher risk for developing chronic infections, which can progress to cirrhosis and liver failure, along with overall increased mortality. Because of the rising trend of HEV serological prevalence among the global population, and the fact that TT-HEV infection can cause serious clinical consequences among those patients most at need for blood donation, the need for screening for TT-HEV has been gaining in prominence as an important public health concern for both developing and developed countries. In the review, we summarise evidence for and notable cases of TT-HEV infections, the various aspects of HEV screening protocols and recent trends in the implementation of TT-HEV broad-based blood screening programmes.

Prevalence of hepatitis E viraemia among blood donors: a systematic review

BACKGROUND

Hepatitis E virus (HEV) is usually transmitted by faecal-oral route. Recent reports have documented HEV viraemia in donated blood units and HEV transmission through blood transfusion. This systematic review summarizes the available data on prevalence of HEV viraemia in blood donors.

METHODS

Electronic databases were searched on 17 December 2018 to identify full-text English papers reporting original data on prevalence of HEV RNA in donated blood units. Two authors independently extracted the relevant data, which were pooled using simple aggregation as well as a random-effects meta-analysis; heterogeneity was assessed using the I2 method.

RESULTS

In all, 59 data sets from 28 countries were identified. The available data showed marked heterogeneity. Of a total of 2 127 832 units studied, 561 (263·6 [95% confidence intervals = 242·7-286·4] per million units) tested positive for HEV RNA. On random-effects meta-analysis, the pooled prevalence was 60·9 [6·7-155·4] per million units. In the viraemic units, HEV RNA titre varied by nearly one million-fold, and most had genotype 3 HEV. The prevalence was higher in blood units with anti-HEV antibodies or elevated alanine aminotransferase. Only nearly one-fourth of viraemic units had anti-HEV antibodies.

CONCLUSIONS

The prevalence of HEV viraemia among healthy blood donors is low, though the available data had limited geographical representation and marked heterogeneity. There is a need for further data on HEV viraemia in blood donors from areas with non-3 HEV genotype preponderance.

Seroprevalence of hepatitis E virus infection in pregnant women: a systematic review and meta-analysis

BACKGROUND

Hepatitis E virus (HEV) infection has emerged as a global public health problem that affects millions of people every year.

OBJECTIVE

Systematically review data on the prevalence of HEV IgG antibody among pregnant women around the world.

DATA SOURCES

Potentially relevant studies were identified by a search of PubMed and ScienceDirect, and by a manual search of the reference lists of identified studies.

STUDY SELECTION

Observational studies in English with no age or area restriction. Reviews, duplicate, book chapters, and other irrelevant studies were excluded.

DATA EXTRACTION

Independent searching by two investigators (TA, THM).

DATA SYNTHESIS

In the 6137 retrieved studies, 15 studies met the inclusion criteria. The studies included 7160 pregnant subjects from 11 countries. Most studies were from Africa. Of the 7160 subjects, 1182 were positive to anti-HEV IgG antibody, and only 66 were anti-HEV IgM antibody positive. The highest seroprevalence of anti-HEV IgG antibody (61.29%) was reported in Sudan and the lowest (3.41%) was reported in Italy. The overall pooled prevalence was 16.51% (95% CI: 0.10-0.23). The heterogeneity level was I ² = 98%; P≤.01.

CONCLUSION

The seroprevalence of anti-HEV IgG antibody among pregnant women differs by geographic location. Further studies are recommended to evaluate incidence, morbidity, and mortality in those areas where the disease is prevalent.

LIMITATIONS

Seroprevalence was only determined for the anti-HEV IgG antibody, which mostly indicates past infection. Heterogeneity was high among the studies in the analysis.

CONFLICT OF INTEREST

None.

Seroprevalence of viral hepatitis A, B, C, D and E viruses in the Hormozgan province southern Iran

BACKGROUND

Viral hepatitis is a global public health problem affecting millions of people worldwide, causing thousands of deaths due to acute and persistent infection, cirrhosis, and liver cancer. Providing updated serologic data can improve both surveillance and disease control programs. This study is aimed to determine the seroprevalence of markers for viral hepatitis (A, B, C, D and E) and the epidemiology of such infections in the general population of southern Iran's Hormozgan province.

METHODS

Between 2016 and 2017, a total of 562 individuals with ages ranging from 1 to 86 years, who visited governmental public laboratories for routine check-ups, were tested for the presence of serological markers to hepatitis virus types A to E using enzyme-linked immunosorbent assays.

RESULTS

The overall anti-hepatitis A virus (HAV) antibody seroprevalence was 93.2% (524/562). The prevalence of anti-hepatitis E virus (HEV) antibodies was 15.8% (89/562) among which 1.6% (9/562) of the seropositive individuals also had evidence of recent exposure to the virus (IgM positivity). Two and a half percent (14/562) were positive for hepatitis B surface (HBs) antigen, whereas 11.6% (65/562) tested positive for anti-hepatitis B core (HBc) antibodies. Among anti-HBc positive patients, 11% (7/65) had HBs Ag and 5% (3/65) were positive for anti-hepatitis D virus (HDV) antibodies. The prevalence of anti-hepatitis C virus (HCV) antibodies was 0.7% (4/562). The seroprevalence of anti-HAV, HEV IgG, anti-HBc antibodies, and HBs Ag increased with age.

CONCLUSION

The present study confirms a high seroprevalence of HAV infection among the examined population and reveals high levels of endemicity for HEV in the region. Planned vaccination policies against HAV should be considered in all parts of Iran. In addition, improvements on public sanitation and hygiene management of drinking water sources for the studied area are recommended.

Hepatitis E virus infection among pregnant women in Africa: systematic review and meta-analysis

BACKGROUND

There have been a number of studies about seroprevalence of HEV among pregnant women in Africa. However, the finding of seroprevalence of HEV infection among pregnant women is variable and inconsistent. Therefore; this systematic review intended to provide the pooled seroprevalence of HEV among pregnant women in Africa.

METHODS

We searched, Pub Med, Science direct, African online journals and Google scholar electronic data bases and all available references until August 30, 2018. We included cross sectional studies and cohort studies. The search was further limited studies done in African pregnant women. Statistical analysis done by using Stata (version 11) software. The overall pooled prevalence of HEV presented by using the forest plot with 95% CI. The methodological qualities of included studies were assessed using Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instruments.

RESULT

The pooled seroprevalence of HEV among pregnant women in Africa was 29.13% (95% CI 14.63-43.63). The highest seroprevalence was 84.3% in Egypt and the lowest 6.6% reported in Gabon. There was highest heterogeneity level where I2 = 99.7%; P < 0.0001.The observed heterogeneity attributed to geographic location/ region, country, assay method used in each study and year of study published. Moreover, HEV seroprevalence varies between countries and within countries. The HEV infection among African pregnant women seems to have a decreasing trend over time.

CONCLUSION

The seroprevalence of HEV among pregnant women in Africa is high. The seroprevalence of HEV among pregnant women differ with geographic location and assay method. Therefore, it is recommended to conduct further research on commercial ELISA kit sensitivity and specificity, molecular tests, incidence, morbidity and mortality and vertical transmission of HEV from mother to infant in Africa.

TRIAL REGISTRATION

CRD42018084963 .

Prevalence of hepatitis G virus infection among 67,348 blood donors in mainland China

Background

Hepatitis G virus (HGV) infection transmitted from blood donors is a concern in China, as many articles about HGV infection in Chinese blood donors from different provinces have been published. This study aimed to evaluate the overall prevalence of HGV infection in Chinese blood donors and analyse the potential risk of HGV infection through blood transfusion in China.

Methods

We performed a literature search in PubMed, EMBASE, Web of Science, the Chinese BioMedical Literature Database (CBM) and the China National Knowledge Infrastructure (CNKI) up to October 2018 regarding the prevalence of HGV in Chinese blood donors. Eligibility assessment and data extraction were conducted independently by 2 researchers, and meta-analysis was performed to synthesize the data. Heterogeneity was evaluated using Cochran’s Q test and quantified using the I² statistic. Subgroup analyses were performed to identify the possible sources of heterogeneity. Publication bias was assessed using both funnel plot and Egger’s tests.

Results

A total of 102 studies with 67,348 blood donors published from 1996 to 2016 and covering 26 provinces or municipalities were included for further analyses. The pooled prevalence of HGV was 3.91% (95%CI: 3.18–4.71%) by enzyme immune assay/enzyme linked immunosorbent assay (EIA/ELISA) and 3.25% (95%CI: 2.35–4.26%) by polymerase chain reaction (PCR). The prevalence of HGV may be significantly affected by region, province or municipality and potentially by the paid/voluntary status of the blood donors. No significant difference was found between plasma and full blood donation.

Conclusions

The prevalence of HGV in blood donors from China was similar to that in blood donors from many other countries and higher than that of some other hepatitis viruses, such as hepatitis B virus. The risk of transfusion-transmitted HGV still exists after routine blood donor screening, especially in those patients coinfected with other hepatitis viruses and/or HIV. On the basis of our study, we may suggest adding HGV screening for blood transfusions in mainland China in the future.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6948-1) contains supplementary material, which is available to authorized users.

High seroprevalence of hepatitis E virus in the ethnic minority populations in Yunnan, China

Hepatitis E virus (HEV) infection is relatively high in the southern regions of China. Yunnan, located in southwestern China, has the highest number of ethnic groups. However, HEV infection in the ethnic population is largely unknown. Therefore, we aimed to investigate the seropositive rate, risk factor, and clinical impact of HEV infection in the ethnic groups of Yunnan. We recruited 1912 individuals from four minority groups in three prefectures of Yunnan province. Epidemiological records on potential risk factors for exposure to HEV and blood biochemical index were analyzed. All the serum samples were tested for anti-HEV IgM/IgG by enzyme-linked immunosorbent assay, and the IgM-positive samples were subjected to nested reverse transcription-PCR to detect HEV RNA. Overall, 1273 individuals (66.58%) were positive for anti-HEV IgG, 16 (0.84%) for anti-HEV IgM, and 64 (3.35%) for anti-HEV IgG and IgM both; none of them had detectable HEV RNA. Multivariate analysis revealed a strong statistical association between ethnic origin and HEV IgG seroprevalence. Anti-HEV IgG reactivity in the Hani ethnic (82.3%; 401/487) population was higher than that in the Naxi (71.9%, 340/473), Bulang (65.1%; 302/464), and Wa (60.2%; 294/488) ethnic populations (p < 0.0001). Older age and male sex were independently associated with the risk of past HEV infection. Moreover, anti-HEV IgG-positive individuals showed significantly higher levels of total and direct bilirubin and alanine amino transferase but significantly lower levels of globulin and low-density lipoprotein, than the respective levels in anti-HEV IgG-negative individuals. Thus, the seroprevalence of HEV infection is high in the ethnic populations of Yunnan, China. It is therefore necessary to increase the surveillance of specific risk groups and raise awareness about the possible infectious diseases to help limit the HEV transmission here.

The current state of adverse event reporting in hemophilia

INTRODUCTION

Replacement of the missing clotting factor is the mainstay of hemophilia treatment. Whilst historically many hemophilia patients were infected with blood-borne viruses transmitted via plasma-derived products, nowadays the formation of alloantibodies against the missing clotting factor is the main adverse event of treatment. Areas covered: This paper provides an overview of the current national and international adverse event reporting systems, what these surveillance schemes taught us about side effects of the products presently in use, and elaborates on how to adapt these systems to the challenges we face with the changing treatment landscape. Expert commentary: Treatment of inherited bleeding disorders was accompanied by severe complications in the past, resulting in major morbidity and mortality. Current products are much safer, but still require monitoring via efficient safety surveillance systems. Adverse events are reported in national and international systems. With many new products entering the market, as well as non-factor replacement therapies, new safety issues may arise. It is important to identify potential adverse events early by making surveillance systems suitable to pick up unknown or unexpected effects, and to recognize and communicate patterns of adverse events rapidly.