Prevalence of hepatitis E virus viremia and antibodies among healthy blood donors in India

Hepatobiliary Manifestations in Thalassemia Patients: A Narrative Review

Thalassemia is one of the most common inherited blood disorders worldwide. This defect causes a disproportionate ratio of α- and β-globin chains resulting in ineffective erythropoiesis leading to increased iron absorption. In patients where the imbalance between α and β globin chains is great they are dependent on blood transfusions for survival. This results in transfusional iron overload but also comes with additional risks such as transfusion-transmissible viral infections like hepatitis B and C. This can lead to various complications like liver fibrosis, cirrhosis and hepatocellular carcinoma, which are important causes with morbidity and mortality in patients of thalassemia today. These hepatobiliary manifestations and their management are briefly discussed in this review. Understanding hepatobiliary complications in thalassemia is vital for optimizing patient care.

The Use of Residual Blood Specimens in Seroprevalence Studies for Vaccine-Preventable Diseases: A Scoping Review

Background: Residual blood specimens offer a cost- and time-efficient alternative for conducting serological surveys. However, their use is often criticized due to potential issues with the representativeness of the target population and/or limited availability of associated metadata. We conducted a scoping review to examine where, when, how, and why residual blood specimens have been used in serological surveys for vaccine-preventable diseases (VPDs) and how potential selection biases are addressed. Methods: The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines and identified relevant papers published in 1990-2022. Results: A total of 601 articles met the inclusion criteria after title, abstract screening, and full-text review. The most studied VPDs using residual blood specimens were COVID-19 (27%), hepatitis E (16%), hepatitis B (10%), influenza (9%), HPV (7%), and measles (7%). Residual blood specimens were primarily sourced from diagnostic specimens (61%) or blood and plasma donations (37%). Almost all articles used specimens linked to basic demographic data (e.g., age and sex), with 47% having access to extended demographic data (e.g., geographic location). Common strategies to address potential biases included comparing results with published estimates (78%) and performing stratified analyses (71%). Conclusions: Residual blood specimens are widely used in seroprevalence studies, particularly during emerging disease outbreaks when rapid estimates are critical. However, this review highlighted inconsistencies in how researchers analyze and report the use of residual specimens. We propose a set of recommendations to improve the analysis, reporting, and ethical considerations of serological surveys using residual specimens.

Seroprevalence of hepatitis A virus and hepatitis E virus antibodies in Madhesh Province, Dhanusha, Nepal

Hepatitis A virus (HAV) and hepatitis E virus (HEV) are thought to have similar routes of transmission and epidemiology in developing countries. This study investigated the seroprevalences of these pathogens among healthy individuals in the Dhanusha district of Madesh Province, Nepal. Ninety serum samples collected between 2022 and 2023 were analyzed by enzyme-linked immunosorbent assay to detect immunoglobulin (Ig)G antibodies against HAV and HEV. Individuals (median age, 23 years; range, 1-45 years) were sorted into five age groups: 1-10, 11-20, 21-30, 31-40 and 41-45 years. Prevalences of HAV and HEV IgGs were 96.7% and 13.3%, respectively. All age groups showed very high positivity rates for HAV antibodies. In contrast, HEV infection rates were extremely low in children, and rapidly increased in adults >31 years old. No significant correlation was found between HAV and HEV seropositivity. Additional studies including other areas in Nepal are required for nationwide sero-surveillance against HAV and HEV.

Assessment of Hepatitis E virus transmission risks: a comprehensive review of cases among blood transfusion recipients and blood donors

Background

Hepatitis E Virus is a major cause of acute and fulminant hepatitis, particularly in developing countries. While the virus is commonly spread through the fecal-oral route, numerous cases of transfusion transmitted Hepatitis E Virus (TT-HEV) have been reported, raising concerns about its transmission via blood transfusions, especially in industrialized countries. The high prevalence of antibodies and viremia among asymptomatic blood donors further heightens the risk of transfusion-related transmission. However, there is still debate about the best strategy to minimize TT-HEV.

Objective

The review was conducted to Summarize the literature on TT-HEV infection cases and the prevalence of HEV among blood donors.

Methods

The databases PubMed, Scopus, Web of Science, Embase, and CINAHL were searched for relevant studies from 2000 to 2022.Serological and molecular screening data of HEV in blood donors were used to gather prevalence and incidence rates.TT-HEV cases were reviewed by examining evidence of HEV infection before and after transfusion.

Results

A total of 121 manuscripts reports the prevalence and incidence of HEV among blood donors and cases of TT-HEV. Twenty-six articles reported confirmed cases of TT-HEV and 101 articles reported on HEV prevalence or incidence among blood donors.

Conclusion

TT-HEV transmission through blood products is a real concern, especially for immunocompromised patients.The risk and severity of infection could vary between immunocompetent and immunosuppressed patients.To increase transfusion safety, the evaluation recommends HEV screening protocols, especially in endemic region.

Higher Risk of HEV Transmission and Exposure among Blood Donors in Europe and Asia in Comparison to North America: A Meta-Analysis

Background and aims: The increasing number of diagnosed hepatitis E virus (HEV) infections in Europe has led to the implementation of the testing of blood products in various countries. Many nations have not yet implemented such screening. To assess the need for HEV screening in blood products worldwide, we conducted a systematic review and meta-analysis assessing HEV RNA positivity and anti-HEV seroprevalence in blood donors. Methods: Studies reporting anti-HEV IgG/IgM or HEV RNA positivity rates among blood donors worldwide were identified via predefined search terms in PubMed and Scopus. Estimates were calculated by pooling study data with multivariable linear mixed-effects metaregression analysis. Results: A total of 157 (14%) of 1144 studies were included in the final analysis. The estimated HEV PCR positivity rate ranged from 0.01 to 0.14% worldwide, with strikingly higher rates in Asia (0.14%) and Europe (0.10%) in comparison to North America (0.01%). In line with this, anti-HEV IgG seroprevalence in North America (13%) was lower than that in Europe (19%). Conclusions: Our data demonstrate large regional differences regarding the risk of HEV exposure and blood-borne HEV transmission. Considering the cost–benefit ratio, this supports blood product screening in high endemic areas, such as Europe and Asia, in contrast to low endemic regions, such as the U.S.

Transmission of Hepatitis E Virus

Transmission of hepatitis E virus (HEV) occurs predominantly by the fecal-oral route. Large epidemics of hepatitis E in the developing countries of Asia and Africa are waterborne and spread through contaminated drinking water. The reservoir of HEV in developed countries is believed to be in animals with zoonotic transmission to humans, possibly through direct contact or the consumption of undercooked contaminated meat. And HEV transmission through blood transfusion, organ transplantation, and vertical transmission has been reported.

Hepatitis B virus and other transfusion-transmissible infections in child blood recipients in Lao People's Democratic Republic: a hospital-based study

INTRODUCTION

Children requiring multiple blood transfusions are at high risk of transfusion-transmissible infections (TTIs). Lao People's Democratic Republic is a low-resource setting where donor blood screening faces challenges. This study aimed to determine the burden of TTIs in children in Vientiane Capital.

METHODS

300 children with transfusion history and 300 controls were recruited. In addition, 49 newly diagnosed transfusion recipients were followed for up to 12 months. Serum was tested for hepatitis B surface antigen and IgG antibodies against parvovirus B19, hepatitis B, C and E viruses.

RESULTS

The patients had a similar prevalence of anti-hepatitis B core antibodies (56; 18.7%) and hepatitis B surface antigen (8; 2.7%) as the controls (58; 19.3% and 9; 3.0%, respectively). However, there was a higher prevalence of an antibody profile suggestive of hepatitis B vaccination (anti-hepatitis B surface antibody positive/anti-hepatitis B core antibody negative) in the transfused group (140/299; 46.8%) than in controls (77/300; 25.7%, p<0.01). All other markers were similar in the patients and controls or higher in the controls: anti-hepatitis C virus (2.7% and 3.3%, p=0.6), anti-hepatitis E virus (7.5% and 12.7%, p=0.006) and anti-parvovirus B19 (2.4% and 8.5%, p=0.001). The longitudinal cohort did not show an increase in any marker over time.

CONCLUSION

Our results suggest no significant role of TTIs in Lao children. The higher prevalence of the hepatitis B vaccination profile in transfusion recipients showed that recommendations to vaccinate before commencing transfusions is at least partially implemented, although there is room for improvement.

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.

Prevalence of Hepatitis E Virus Infection Among Blood Donors in the Eastern Province of Saudi Arabia

PURPOSE

Hepatitis E virus (HEV) causes acute hepatitis in humans and constitutes a major problem for immunocompromised patients, patients with hematological diseases, and pregnant women. It is transmitted mainly through fecal oral route; however, transmission through blood and blood products is reported globally and becoming a health concern. We sought to determine the prevalence of HEV among blood donors in the Eastern Province of Saudi Arabia using molecular as well as serological assays to assess the safety of blood transfusion and the need for HEV screening among blood donors.

PATIENTS AND METHODS

A total of 806 whole blood samples were collected from blood donors between May and November 2020 and tested for anti-HEV IgG and IgM antibodies by ELISA and for HEV RNA by RT-PCR.

RESULTS

The overall seroprevalence of HEV IgG antibodies was 3.2% with no statistically significant difference between the non-Saudis (3.28%) and Saudis (3.17%) (p value 0.929) or between males (3.14%) and females (4.88%) (p value 0.527). None of the IgG positive individuals had IgM antibodies. HEV RNA was not detected in any of the blood donors.

CONCLUSION

HEV seroprevalence is low among blood donors in the Eastern Province of Saudi Arabia and may constitute minimal risk for transfusion associated infections.

Setting a Course for Preventing Hepatitis E in Low and Lower-Middle-Income Countries: A Systematic Review of Burden and Risk Factors

BACKGROUND

Hepatitis E virus (HEV) is responsible for outbreaks of acute jaundice in Africa and Asia, many of which occur among displaced people or in crisis settings. Although an efficacious vaccine for HEV has been developed, we lack key epidemiologic data needed to understand how best to use the vaccine for hepatitis E control in endemic countries.

METHODS

We conducted a systematic review of articles published on hepatitis E in low-income and lower-middle-income countries in Africa and Asia. We searched PubMed, Scopus, and Embase databases to identify articles with data on anti-HEV immunoglobulin (Ig)G seroprevalence, outbreaks of HEV, or risk factors for HEV infection, disease, or death, and all relevant data were extracted. Using these data we describe the evidence around temporal and geographical distribution of HEV transmission and burden. We estimated pooled age-specific seroprevalence and assessed the consistency in risk factor estimates.

RESULTS

We extracted data from 148 studies. Studies assessing anti-HEV IgG antibodies used 18 different commercial assays. Most cases of hepatitis E during outbreaks were not confirmed. Risk factor data suggested an increased likelihood of current or recent HEV infection and disease associated with fecal-oral transmission of HEV, as well as exposures to blood and animals.

CONCLUSIONS

Heterogeneity in diagnostic assays used and exposure and outcome assessment methods hinder public health efforts to quantify burden of disease and evaluate interventions over time and space. Prevention tools such as vaccines are available, but they require a unified global strategy for hepatitis E control to justify widespread use.

A systematic review and meta-analysis of predictors of human hepatitis E virus exposure in non-endemic countries

The reported incidence of clinical hepatitis E cases is rising in some non-endemic countries, with concurrent concerns regarding potential hepatitis E virus (HEV) contamination of the blood supply. Therefore, the characterization of major potential sources of human HEV exposure is important to inform risk assessment and public health policy. A systematic review was conducted, including a comprehensive search in six electronic bibliographic databases, verified by hand-searching reference lists of HEV reviews, and a grey literature search, of the broad research question 'what is the evidence of the association between predictors of human HEV exposure, and HEV IgG seropositivity, in non-endemic countries?' Using forms designed a priori, captured studies were appraised at first-level screening, second-level characterization, and third-level data extraction and risk of bias assessment. Meta-analysis yielded summary estimates of association between potential predictors and odds of HEV seropositivity. Meta-analysis and meta-regression of the odds of HEV seroprevalence in specific groups characterized potential sources of HEV exposure. From 4,163 captured citations, 245 relevant studies underwent data extraction, investigating HEV seroprevalence or predictors in both healthy subjects and targeted patient groups. Across these groups, increasing age was a predictor of HEV IgG seropositivity. Both human immunodeficiency virus patients and haemodialysis patients had significantly increased odds of HEV seropositivity relative to the general population. Working with pigs, in forestry, or in hospitals, was significantly associated with increased odds of HEV seropositivity, as were consumption of meat, pork or game meat, or hunting. Chronological time was not associated with HEV seropositivity within our data sets. Further study of the distribution of potential dietary or behavioural predictors between high and lower prevalence areas within non-endemic countries could improve our understanding of the relative importance of specific HEV transmission pathways.

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.

Blood transfusion is unlikely to be a source for hepatitis E virus transmission in India

INTRODUCTION

Transmission of hepatitis E virus (HEV) through transfusion has been reported from countries where genotype 3 virus is predominant. Data from countries with predominantly genotype 1 HEV, such as India, are limited. We studied the risk of HEV transmission following transfusion of blood or blood components in India.

METHODS

Adult patients undergoing cardiac surgery who received transfusion of blood or blood products in the peri-operative period and who lacked history of any transfusion or surgery in the preceding 1 year were studied. A pre-transfusion blood specimen was collected for IgG anti-HEV antibody test. For the participants who were seronegative for anti-HEV, follow up specimens were collected at every 2-3-month intervals for up to 6 months after surgery and were tested for IgM and IgG anti-HEV antibodies.

RESULTS

Of the 335 participants originally enrolled, 191 (57%) could be followed up. Of them, 103 (53.9%) were seropositive for HEV IgG at baseline and were excluded. Of the remaining 88 participants (age 42 ± 14.1 years; 55 [63%] male), none reported hepatitis-like illness during the follow up period of 81 ± 23 days. Also, none of these 88 participants was found to have seroconversion to anti-HEV IgM or IgG positivity in the follow up specimens.

CONCLUSION

Transfusion-mediated transmission of HEV was not observed in our cohort and may be infrequent in the Indian population, where genotype 1 is the predominant HEV type.

Prevalence of hepatitis E virus infection in multiple transfused Brazilian patients with thalassemia and sickle cell disease

Hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide. The virus is acquired by fecal-oral route; however, it can also be transmitted by blood transfusion. The objective of the study was to examine anti-HEV immunoglobulin G and HEV RNA prevalence in multiple transfused patients with thalassemia and sickle cell disease (SCD), and in blood donors. The HEV seroprevalence in the patients was 13% (20% in thalassemics; 7.7% in SCD), and 11% in blood donors. No positive result for HEV RNA was obtained. This is a pioneer study examining HEV circulation in Brazilian patients with hemoglobinopathies.

Hepatitis E virus: reasons for emergence in humans

Hepatitis E virus (HEV) infects both humans and other animal species. Recently, we have seen a steady increase in autochthonous cases of human HEV infection in certain areas especially in Europe, and large outbreaks in several African countries among the displaced population. This mini-review critically analyzes potential host, environmental, and viral factors that may be associated with the emergence of hepatitis E in humans. The existence of numerous HEV reservoir animals such as pig, deer and rabbit results in human exposure to infected animals via direct contact or through animal meat consumption. Contamination of drinking, irrigation and coastal water by animal and human wastes lead to emergence of endemic cases in industrialized countries and outbreaks in displaced communities especially in war-torn countries.