Hepatitis E virus (HEV)-The Future

Effect and mechanism of C-terminal cysteine on the properties of HEV p222 protein

Preliminary investigations have demonstrated that the cysteines located at the C-terminus of HEV ORF2 protein exhibits disulfide bonding capability during virus-like particles (VLPs) assembly. However, the effect and mechanism underlying the pairing of disulfide bonds formed by C627, C630, and C638 remains unclear. The p222 protein encompasses C-terminus and serves as a representative of HEV ORF2 to investigate the specific impacts of C627, C630, and C638. The three cysteines were subjected to site-directed mutagenesis and expressed in prokaryotes; Both the mutated proteins and p222 underwent polymerization except for p222A; Surprisingly, only p222 was observed as abundant spherical particles under transmission electron microscope (TEM); Stability and immunogenicity of the p222 exhibited higher than other mutated proteins; LC/MS/MS analysis identified four disulfide bonds in the p222. The novel findings suggest that the three cysteines contribute to structural and functional properties of ORF2 protein, highlighting the indispensability of each cysteine.

Hepatitis E Virus Infection in Voluntary Blood Donors in the Russian Federation

Transfusion-transmitted hepatitis E virus (HEV) infection is an increasing concern in many countries. We investigated the detection rate of HEV viremia in blood donors in Russia. A total of 20,405 regular repetitive voluntary non-renumerated blood donors from two regions (Moscow and Belgorod) were screened for HEV RNA using the cobas® HEV test in mini-pools of six plasma samples. Samples from each reactive pool were tested individually. The average HEV RNA prevalence was 0.024% (95% CI: 0.01-0.05%), or 1 case per 4081 donations. No statistically significant differences in HEV RNA prevalence were observed between the two study regions. The PCR threshold cycle (Ct) values ranged from 25.0 to 40.5 in reactive pools, and from 20.9 to 41.4 in reactive plasma samples when tested individually. The HEV viremic donors had different antibody patterns. Two donor samples were reactive for both anti-HEV IgM and IgG antibodies, one sample was reactive for anti-HEV IgM and negative for anti-HEV IgG, and two samples were seronegative. At follow-up testing 6 months later, on average, four donors available for follow-up had become negative for HEV RNA and positive for anti-HEV IgG. The HEV ORF2 sequence belonging to HEV-3 sub-genotype 3a was obtained from one donor sample. The sequencing failed in the other four samples from viremic donors, presumably due to the low viral load. In conclusion, the HEV RNA detection rate in blood donors in Russia corresponds with data from other European countries, including those that implemented universal donor HEV screening. These data support the implementation of HEV RNA donor screening to reduce the risk of transfusion-transmitted HEV infection in Russia.

Global burden of acute hepatitis E between 1990 and 2019 and projections until 2030

BACKGROUND AND AIMS

Acute hepatitis E (AHE) is still a public health issue worldwide. Here, we report the global burden of AHE in 204 countries and territories from 1990 to 2019 by age, sex and socio-demographic index (SDI), and predict the future trends to 2030.

METHODS

Data on AHE were collected from the Global Burden of Diseases, Injuries and Risk Factors Study 2019. The average annual percentage change (AAPC) and joinpoint analysis were used to determine the burden trend.

RESULTS

In 2019, there were 19.47 million (95% UI, 16.04 to 23.37 million) incident cases of AHE globally, with a 19% increase since 1990. Age-standardized rate (ASR) of disability-adjusted life years (DALYs), prevalent and incident cases declined from 1990 to 2019. In 2019, the ASR of incidence, prevalence and DALYs due to HEV infection were highest in the same regions of South Asia for both sexes. Southern Sub-Saharan Africa presented the highest increases in the ASR for incidence of HEV infection in both males (AAPC = .25) and females (AAPC = .24) from 1990 to 2019. Incident cases are higher in males than females before 55-59 years old. The SDI values were negatively correlated with the age-standardized DALYs. Between 2019 and 2030, the ASR for incidence and prevalence of HEV for both sexes showed an increasing trend.

CONCLUSIONS

Although the overall ASR of AHE decreased, the burden of AHE remains an underappreciated problem for society. The findings may provide useful information for policymakers to develop appropriate strategies aimed at reducing the burden of AHE.

Barriers toward xenotransplantation in Arab World

Organ transplant is a crucial therapeutic strategy offering a life-saving and transformative medical intervention. It provides an opportunity to improve their quality of life and increase their lifespan. The shortage of organs remains a critical global challenge, leading to a prolonged waiting times for organ receivers, which contributes to an increase in morbidity and mortality rates. Hence, xenotransplantation offered a promising solution to the global shortage of organs through the use of animal organs, leading to an increase in donor availability, reducing waiting times, minimizing organ trafficking, improving genetic engineering advancements, and driving scientific innovation. Even though xenotransplantation has many benefits in the clinical setting, it has many barriers that are hindering its achievements and constraining its occurrence. Some barriers to xenotransplant are general, such as the immunological barrier, while others are specific to certain regions due to local causes. The Arab region exhibits disparities in clinical settings compared to the global context, marked by the huge economic crisis and a shortage of trained healthcare professionals. Considering the huge resources and advancements needed in the field of xenotransplantation, this review aims to explore the specific barriers toward xenotransplantation in the Arab countries, highlighting the challenges to overcome these barriers.

Pet safety guidelines for pediatric transplant recipients

Approximately 70% (90.5 million) of United States (US) households own at least one pet. Dogs are the most common, making up about 38% of all household pets, followed by cats, which make up 25%. Other pets such as fish, birds, reptiles, and small animals such as hamsters, gerbils, and rabbits are less common household members. Pets are often considered a part of the family and there are significant medical and psychosocial benefits to pet ownership; however, the possibility of disease transmission exists related to the type of animal and infectious organism, and specific human risk factors. Immunocompromised individuals may be at increased risk of serious illness from zoonotic infections. During the transplant evaluation and routinely posttransplant, the multidisciplinary team should inquire about pet ownership and animal exposures to guide on potential risks. This review discusses the most common diseases seen in various household pets including dogs, cats, birds, fish, and some farm animals. We will also present guidelines for pet safety and include strategies to decrease the risk of infection while supporting the benefits of pet ownership after transplant.

Unraveling swine hepatitis E in the central region of Argentina through ELISA development and epidemiological insights

Hepatitis E virus (HEV) is a public health concern globally, causing acute viral hepatitis in humans. Genotype-3 HEV (HEV-3), the most frequently genotype detected in South America, is zoonotic and the main reservoirs are the domestic pig and wild boar. Circulation of HEV-3 in Argentina has been confirmed in humans as well as in pig herds, wild boar and environmental waters. However, data are scarce mainly due to the inaccessibility of serological assays in this country. In order to provide insights in the epidemiology of HEV in swine in Argentina, we developed an indirect ELISA based on the native recombinant protein ORF2 and conducted a serological survey to determine the prevalence of seropositive swine in small-scale pig farms in the central region of Argentina. The method was evaluated in a panel of 157 serum samples, resulting in relative sensitivity of 98.6 % (95 % CI 95 %-100 %) and relative specificity of 97.7 % (95 % CI 94 %-100 %) compared to a commercial test. An almost perfect agreement was obtained between the two tests (Kappa index of 0.961). A survey on 294 samples from 49 small-scale farms resulted in a seropositivity rate of 54 %. Seropositive animals were found in 34 out of 49 (69.4 %) farms. Most of the farms (70.6 %) had over 50 % of seropositive animals. The wide spreading of HEV in the swine population of Tandil, Argentina, underscore the need to better understand the epidemiology of HEV in the region, enabling the implementation of targeted interventions to mitigate the impact of this virus on public health.

An Update in Knowledge of Pigs as the Source of Zoonotic Pathogens

The available data indicate that the human world population will constantly grow in the subsequent decades. This constant increase in the number of people on the Earth will lead to growth in food demand, especially in food of high nutritional value. Therefore, it is expected that the world livestock population will also increase. Such a phenomenon enhances the risk of transmitting pathogens to humans. As pig production is one of the most significant branches of the world's livestock production, zoonoses of porcine origins seem to be of particular importance. Therefore, in this review, we aim to introduce the latest data concerning, among other things, epidemiology and available preventive measures to control the most significant porcine zoonoses of viral, bacterial, and parasitic origin.

Prevalence and Risk Factors for Hepatitis E Virus in Wild Boar and Red Deer in Portugal

Hepatitis E virus (HEV) is a zoonotic foodborne virus with an annual infection prevalence of 20 million human cases, which seriously affects public health and economic development in both developed and developing countries. To better understand the epidemiology of HEV in Central Portugal, a cross-sectional study was conducted from 2016 to 2023 with sera samples from wild ungulates. The seroprevalence and risk factors for HEV seropositivity were evaluated in the present study. Specifically, antibodies against HEV were determined by a commercial enzyme-linked immune-sorbent assay (ELISA). Our results show that in the 650 sera samples collected from 298 wild red deer and 352 wild boars in Portugal, 9.1% red deer and 1.7% wild boar were positive for antibodies to HEV. Regarding age, the seropositivity in juvenile wild ungulates was 1.3%, whereas it was 7.2% in adults. Logistic regression models investigated risk factors for seropositivity. The odds of being seropositive was 3.6 times higher in adults than in juveniles, and the risk was 4.2 times higher in red deer than in wild boar. Both wild ungulate species were exposed to HEV. The higher seroprevalence in red deer suggests that this species may make a major contribution to the ecology of HEV in Central Portugal. Further research is needed to understand how wildlife affects the epidemiology of HEV infections in Portugal.

The Re-Emergence of Hepatitis E Virus in Europe and Vaccine Development

Hepatitis E virus (HEV) is one of the leading causes of acute viral hepatitis. Transmission of HEV mainly occurs via the fecal-oral route (ingesting contaminated water or food) or by contact with infected animals and their raw meat products. Some animals, such as pigs, wild boars, sheep, goats, rabbits, camels, rats, etc., are natural reservoirs of HEV, which places people in close contact with them at increased risk of HEV disease. Although hepatitis E is a self-limiting infection, it could also lead to severe illness, particularly among pregnant women, or chronic infection in immunocompromised people. A growing number of studies point out that HEV can be classified as a re-emerging virus in developed countries. Preventative efforts are needed to reduce the incidence of acute and chronic hepatitis E in non-endemic and endemic countries. There is a recombinant HEV vaccine, but it is approved for use and commercially available only in China and Pakistan. However, further studies are needed to demonstrate the necessity of applying a preventive vaccine and to create conditions for reducing the spread of HEV. This review emphasizes the hepatitis E virus and its importance for public health in Europe, the methods of virus transmission and treatment, and summarizes the latest studies on HEV vaccine development.

Comparative Analysis on Clinical Characteristics Among Patients with Acute Hepatitis A Virus (HAV) and Patients with Acute Hepatitis E Virus (HEV): A Single-Center Retrospective Study from Bulgaria

Introduction

The acute viral hepatitis was one of the most common conditions in daily clinical practice varying in different parts of the world. The aim of the present study was to perform a comparative analysis on clinical characteristics among patients with acute hepatitis A virus (HAV) infection and patients with acute hepatitis E virus (HEV) infection admitted to the Military Medical Academy (MMA), Sofia, Bulgaria.

Methods

A retrospective study was performed at MMA, between 1 January 2016 and 31 December 2021. The etiological diagnosis was confirmed by enzyme-linked immunosorbent assay (ELISA) HAV/HEV IgM serology assays.

Results

The current survey included 231 patients with mean age 45.11 ± 16.08 years (95% confidence interval: 43.04-47.19). According to the case definition, inclusion and exclusion criteria, persons were divided into two groups: patients with acute HAV infection (68.4%; 158/231) and patients with acute HEV infection (31.6%; 73/231). Males with HEV had 3.091 times the odds of comorbidity "hypertension" than males with HAV (p = 0.032). There were almost equal odds of increased ALT (odds ratio = 0.999; p = 0.003) in men with HEV and men with HAV. Females with HEV had 5.161 times the odds of comorbidity "hypertension" compared with females with HAV (p = 0.049). We found almost equal odds for elevated ALT in women with HEV and women with HAV (OR = 0.999; p = 0.025). In the non-elderly group (<60-year-old), HEV individuals had 4.544 and 10.560 times the odds of comorbidities "hypertension" and "cardiovascular diseases" compared with HAV patients (p < 0.05). We found almost equal odds for elevated ALT in HEV patients and HAV participants (OR = 0.998; p = 0.002).

Conclusion

The results from the current study may support the physicians daily care for patients with acute HAV and acute HEV.

A case of persistent hepatitis E virus infection in a young adult with no medical history

Most patients with hepatitis E virus (HEV) infection are asymptomatic and improve naturally without any treatment, but even non-immunocompromised individuals may develop persistent HEV infections and should be monitored regularly for the onset.

Infection and clinical xenotransplantation: Guidance from the Infectious Disease Community of Practice of the American Society of Transplantation

This guidance was developed to summarize current approaches to the potential transmission of swine-derived organisms to xenograft recipients, health care providers, or the public in clinical xenotransplantation. Limited specific data are available on the zoonotic potential of pig pathogens. It is anticipated that the risk of zoonotic infection in xenograft recipients will be determined by organisms present in source animals and relate to the nature and intensity of the immunosuppression used to maintain xenograft function. Based on experience in allotransplantation and with preclinical models, viral infections are of greatest concern, including porcine cytomegalovirus, porcine lymphotropic herpesvirus, and porcine endogenous retroviruses. Sensitive and specific microbiological assays are required for routine microbiological surveillance of source animals and xenograft recipients. Archiving of blood samples from recipients, contacts, and hospital staff may provide a basis for microbiological investigations if infectious syndromes develop. Carefully implemented infection control practices are required to prevent zoonotic pathogen exposures by clinical care providers. Informed consent practices for recipients and their close contacts must convey the lack of specific data for infectious risk assessment. Available data suggest that infectious risks of xenotransplantation are manageable and that clinical trials can advance with carefully developed protocols for pretransplant assessment, syndrome evaluation, and microbiological monitoring.

Hepatitis E Virus (HEV) in Makkah, Saudi Arabia: A Population-Based Seroprevalence Study

BACKGROUND

The Hepatitis E virus (HEV) is a common cause of viral hepatitis worldwide. Little is known about the seroprevalence of HEV in the general population of Saudi Arabia.

METHODS

A community-based cross-sectional HEV seroprevalence study was conducted in Makkah, Saudi Arabia. Anti-HEV IgG antibodies were detected in sera using an in-house ELISA. The frequency of HEV sageerology and its correlation with demographic, and environmental factors were evaluated.

RESULTS

Enrollment consisted of 1329 individuals, ages ranged from 8 to 88 years, the mean age was 30.17 years, the median age was 28yrs, and the male: female ratio was 1.15. The overall seroprevalence was 23.8% (316/1329). Males had significantly higher seroprevalence than females (66.1 vs. 33.9%; p < 0.001). Seroprevalence had significant correlations with age, occupation, and lack of regular water supply and housing conditions.

CONCLUSIONS

This is the first HEV community-based seroprevalence study from Saudi Arabia. Results show that the HEV is endemic in Makkah and affects all age groups and occupations. HEV affects more males than females and those living in crowded accommodations without a regular supply of water. Further studies are required across all regions of Saudi Arabia to determine the country's seroprevalence of active or past infection using tests for HEV IgG, HEV IgM antibodies and/or HEV RNA and underlying determinants of transmission.

Moving xenotransplantation from bench to bedside: Managing infectious risk

Xenotransplantation of organs from swine in immunosuppressed human recipients poses many of the same challenges of allotransplantation relative to the risk for infection, malignancy, or graft rejection in proportion to the degree of immunosuppression and epidemiologic exposures. The unique features of xenotransplantation from pigs relative to infectious risk center on the potential for unusual organisms derived from swine causing productive infection, "xenosis" or "xenozoonosis," in the host. Based on experience in allotransplantation, the greatest hazard is due to viruses, due to the relative lack of information regarding the behavior of these potential pathogens in humans, the absence of validated serologic and molecular assays for swine-derived pathogens, and uncertainty regarding the efficacy of therapeutic agents for these organisms. Other known, potential pathogens (i.e., bacteria, fungi, parasites) tend to be comparable to those of humans. Concerns remain for unknown organisms in swine that may replicate in immunosuppressed humans. Clinical trials of genetically modified organs sourced from swine in immunosuppressed humans with organ failure are under development. Such trials require informed consent regarding potential infectious risks to the recipient, determination of breeding characteristics of swine, assessments of potential risks to the public and healthcare providers, consideration of ethical issues posed by this novel therapy, and defined strategies to monitor and address infectious episodes that may be encountered by healthcare teams. Clinical trials in xenotransplantation will allow improved definition of potential infectious risks.

Hepatitis A and E Viruses in Mussels from Cherrat Estuary in Morocco: Detection by Real-Time Reverse Transcription PCR Analysis

The aim of the present study was to evaluate hepatitis A virus (HAV) and hepatitis E virus (HEV) contamination in mussels (Mytilus galloprovincialis) from Cherrat estuary (Moroccan Atlantic Coast), Morocco. In total, 52 samples (n = 12 mussels/each) were collected at four sites in the estuary, monthly, between March 2019 and March 2020. HAV and HEV were detected by real-time reverse transcription polymerase chain reaction (RT-PCR) according to the ISO/TS 15216 method. HAV was detected in 46.15% of analyzed samples. Conversely, HEV was not detected in any sample. Moreover, the HAV detection rate was significantly associated with seasonal rainfall variations. This qualitative study on HAV and HEV contamination highlights the interest of studying mussel samples from wild areas. As HAV presence in mussels represents a potential health risk, viral contamination surveillance of mussels is necessary to protect consumers. HAV shellfish contamination must be monitored at Cherrat estuary because of the role played by shellfish as HAV reservoirs and/or vehicles in fecal-oral HAV transmission.

Presence of hepatitis E virus in testis of naturally infected wild boars

The hepatitis E virus (HEV) is the main cause of viral acute hepatitis in the world, affecting more than 20 million people annually. During the acute phase of infection, HEV can be detected in various body fluids, which has a significant impact in terms of transmission, diagnosis or extrahepatic manifestations. Several studies have isolated HEV in the genitourinary tract of humans and animals, which could have important clinical and epidemiological implications. So, our main objective was to evaluate the presence of HEV in testis of naturally infected wild boars (Sus scrofa). For it, blood, liver, hepatic lymph node and testicle samples were collected from 191 male wild boars. The presence of HEV was evaluated in serum by PCR, as well as in tissues by PCR and immunohistochemistry. Four animals (2.09%; 95%CI: 0.82-5.26) showed detectable HEV RNA in serum, being confirmed the presence of HEV-3f genotype in three of them by phylogenetic analysis. HEV was also detected in liver and/or hepatic lymph nodes of the four animals by RT-PCR, as well as by immunohistochemistry analysis. Only one of these wild boars also showed detectable viral load in testis, observing HEV-specific labelling in a small number of fibroblasts and some Sertoli cells. Our results confirm the presence of HEV genotype 3 in naturally infected wild boar testis, although no associated tissue damage was evidenced. This study does not allow us to discard semen as a possible source of HEV transmission in suids. Future experimental studies are necessary to evaluate the impact of HEV genotype 3 on fertility and the possibility of transmission through sexual contact in this specie.

Hepatitis E Virus (HEV): Identification of Subtypes 3b and 3m in Wild Boar Population in Liguria Region, Italy

The wild boar is an important natural reservoir for the zoonotic transmission of the hepatitis E virus (HEV) around the world. In particular, HEV genotypes 3 and 4 are an emerging problem in industrialized countries, as the number of wild boars has increased, and their territory is ever closer to farms and populated areas. This study describes the HEV prevalence and geographic circulation among wild boar populations in the Ligurian region (Italy) during the period 2019-2022. Liver samples from 849 wild boars were analyzed for HEV RNA using real-time RT-PCR; positive samples were then subjected to sequencing and phylogenetic analysis. Overall, 6.7% of the wild boars were positive for HEV RNA; however, in the last two years, the percentage of positive animals almost doubled. Phylogenetic analysis showed that wild boar HEV sequences belonged to genotype 3 and clustered within subtypes 3a and 3c, and, for the first time in Italy, subtypes 3b and 3m were identified. Interestingly, 13 sequences could not be assigned to a recognized subtype. Furthermore, the results showed different circulations of identified subtypes across the territory. These findings increase the knowledge of HEV-3 heterogeneity in Italy and describe the role of wild boars in maintaining an active viral circulation in the environment.

Global public health implications of human exposure to viral contaminated water

Enteric viruses are common waterborne pathogens found in environmental water bodies contaminated with either raw or partially treated sewage discharge. Examples of these viruses include adenovirus, rotavirus, noroviruses, and other caliciviruses and enteroviruses like coxsackievirus and polioviruses. They have been linked with gastroenteritis, while some enteric viruses have also been implicated in more severe infections such as encephalitis, meningitis, hepatitis (hepatitis A and E viruses), cancer (polyomavirus), and myocarditis (enteroviruses). Therefore, this review presents information on the occurrence of enteric viruses of public health importance, diseases associated with human exposure to enteric viruses, assessment of their presence in contaminated water, and their removal in water and wastewater sources. In order to prevent illnesses associated with human exposure to viral contaminated water, we suggest the regular viral monitoring of treated wastewater before discharging it into the environment. Furthermore, we highlight the need for more research to focus on the development of more holistic disinfection methods that will inactivate waterborne viruses in municipal wastewater discharges, as this is highly needed to curtail the public health effects of human exposure to contaminated water. Moreover, such a method must be devoid of disinfection by-products that have mutagenic and carcinogenic potential.

Virus Safety of Xenotransplantation

The practice of xenotransplantation using pig islet cells or organs is under development to alleviate the shortage of human donor islet cells or organs for the treatment of diabetes or organ failure. Multiple genetically modified pigs were generated to prevent rejection. Xenotransplantation may be associated with the transmission of potentially zoonotic porcine viruses. In order to prevent this, we developed highly sensitive PCR-based, immunologicals and other methods for the detection of numerous xenotransplantation-relevant viruses. These methods were used for the screening of donor pigs and xenotransplant recipients. Of special interest are the porcine endogenous retroviruses (PERVs) that are integrated in the genome of all pigs, which are able to infect human cells, and that cannot be eliminated by methods that other viruses can. We showed, using droplet digital PCR, that the number of PERV proviruses is different in different pigs (usually around 60). Furthermore, the copy number is different in different organs of a single pig, indicating that PERVs are active in the living animals. We showed that in the first clinical trials treating diabetic patients with pig islet cells, no porcine viruses were transmitted. However, in preclinical trials transplanting pig hearts orthotopically into baboons, porcine cytomegalovirus (PCMV), a porcine roseolovirus (PCMV/PRV), and porcine circovirus 3 (PCV3), but no PERVs, were transmitted. PCMV/PRV transmission resulted in a significant reduction of the survival time of the xenotransplant. PCMV/PRV was also transmitted in the first pig heart transplantation to a human patient and possibly contributed to the death of the patient. Transmission means that the virus was detected in the recipient, however it remains unclear whether it can infect primate cells, including human cells. We showed previously that PCMV/PRV can be eliminated from donor pigs by early weaning. PERVs were also not transmitted by inoculation of human cell-adapted PERV into small animals, rhesus monkey, baboons and cynomolgus monkeys, even when pharmaceutical immunosuppression was applied. Since PERVs were not transmitted in clinical, preclinical, or infection experiments, it remains unclear whether they should be inactivated in the pig genome by CRISPR/Cas. In summary, by using our sensitive methods, the safety of xenotransplantation can be ensured.

Hepatitis E Virus Detection in Hunted Wild Boar Liver and Muscle Tissues in Central Italy

In different European countries, including Italy, hepatitis E virus (HEV) has been recognized as an emerging public health concern. Humans are infected through the orofecal route by the ingestion of contaminated uncooked or undercooked animal-origin foodstuffs. Wild boars (Sus scrofa) have gained a crucial role as viral reservoirs. HEV-3 is the most frequently identified genotype from hunted wild boar liver and muscle tissues. The Marche region, more specifically Ascoli Piceno province, is characterized by a rooted hunting tradition and related product consumption. In this research study, 312 liver and 296 muscle specimens were screened using biomolecular assays, and HEV RNA was detected from 5.45% and 1.35% of liver and muscle samples, respectively. Phylogenetic analysis revealed that positive animals were infected by genotype 3 subtype c. Based on the environmental pathogen characteristics, HEV has also evolved to guarantee its survival in a wild environment. Therefore, wild boars and ruminants have a key role in its persistence. Epidemiological data regarding HEV circulation have resulted as necessary, and biomolecular analysis represents an important means of monitoring and establishing preventive measures. A multidisciplinary approach could provide a wide perspective regarding HEV and infectious implications on human, animal, and environmental health.

Epidemiological Profile of a Human Hepatitis E Virus Outbreak in 2018, Chattogram, Bangladesh

Hepatitis E virus (HEV) is a waterborne zoonotic disease that can result in a high fatality rate in pregnant women and infants. In 2018, a large HEV outbreak emerged in Chattogram, Bangladesh, resulting in 2800 cases and a significant public health response to mitigate the transmission. While the source of the outbreak remained poorly understood, authorities suggested that possible risk factors for HEV infection included contamination of water supply, exacerbated by concurrent severe flooding events in the community. A cross-sectional study was conducted to investigate the distribution and risk factors for HEV seroprevalence between January and December 2018 in the Chattogram city area. A total of 505 blood samples were collected from symptomatic patients of 10 hospitals who met the case definition for an HEV infection. Standard ELISA tests were performed in all patients to identify anti-HEV antibodies. The size and location of HEV seroprevalence clusters within Chattogram were investigated using SaTScan. We investigated the association between risk of HEV infection and individual and environmentally lagged risk factors using Bernoulli generalised linear regression models. Our results indicate an overall HEV seroprevalence of 35% with significant variation according to sex, source of drinking water, and boiling of drinking water. A positive cross-correlation was found between HEV exposure and precipitation, modified normalised difference water index (MNDWI), and normalised difference vegetation index (NDVI). Our model indicated that risk of infection was associated with sex, age, source of drinking water, boiling of water, increased precipitation, and increased MNDWI. The results from this study indicate that source and boiling of drinking water and increased precipitation were critical drivers of the 2018 HEV outbreak. The communities at highest risk identified in our analyses should be targeted for investments in safe water infrastructure to reduce the likelihood of future HEV outbreaks in Chattogram.

Hepatitis E virus detection in hunted wild boar (Sus scrofa) livers in Central Italy

Hepatitis E virus (HEV) is a zoonotic pathogen, responsible for numerous cases of infection in humans. Transmission occurs through the orofecal route, and ingestion of contaminated foods represents an important risk factor for final consumer's health. Wild animal species, in particular wild boar (Sus scrofa), are the main virus reservoirs; liver is the target organ, from which, through the hematic diffusion, HEV reaches different tissues and organs, as muscular one. The hygienic-sanitary critical issues connected with game meat food chain in general, and particularly wild boar, with special regards to any geographical area where this animal species can be directly in contact with humans, domestic ones (i.e., domestic pig), and other wild reservoirs (i.e., wild ruminants), finds favorable environmental conditions, have induced us to conduce the present scientific investigation. During the hunting season 2019/2020, a total of 156 wild boar livers were collected from provided plucks at slaughterhouse in Ascoli Piceno. Nested RT-PCR was used for the viral RNA detection. Results demonstrated a positivity of 5.12% (8/156), and the circulation in the screened area of genotype 3 subtype c, which is frequently identified in Central Italy. HEV sanitary relevance and the emerging role of any food chains in its transmission impose further detailed studies. The molecular screening of hunted wild boars' livers can provide important information about virus's circulation in wild animal populations in a specific area.

Potential Zoonotic Swine Enteric Viruses: The Risk Ignored for Public Health

Swine could serve as a natural reservoir for a large variety of viruses, including potential zoonotic enteric viruses. The presence of viruses with high genetic similarity between porcine and human strains may result in the emergence of zoonotic or xenozoonotic infections. Furthermore, the globalization and intensification of swine industries exacerbate the transmission and evolution of zoonotic viruses among swine herds and individuals working in swine-related occupations. To effectively prevent the public health risks posed by zoonotic swine enteric viruses, designing, and implementing a comprehensive measure for early diagnosis, prevention, and mitigation, requires interdisciplinary a collaborative ''One Health" approach from veterinarians, environmental and public health professionals, and the swine industry. In this paper, we reviewed the current knowledge of selected potential zoonotic swine enteric viruses and explored swine intensive production and its associated public health risks.

Hepatitis E virus genotype 3 in bovine livers slaughtered in the state of Rio Grande do Sul, Brazil

Foodborne viruses are becoming a global concern as they overwhelm the health system and have the potential to spread globally. Among them, some genotypes of hepatitis E virus (HEV), which is one of the main causes of acute hepatitis in humans, have a zoonotic potential and can be found in foods of animal origin. Infected farm animals are a possible source of the virus, either by direct contact with animal excreta or meat. In the present study, 240 bovine liver samples from slaughter carried out in Rio Grande do Sul (RS), Brazil, were analyzed and tested for the presence of HEV. After performing PCR, 5.4% of positive samples were observed. One of the samples could be identified by molecular phylogenetic analysis as belonging to genotype 3, for which pigs are natural reservoirs, but has not been reported in bovine meat and products so far.

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: An emerging enigmatic and underestimated pathogen

Hepatitis E virus (HEV) is an RNA virus causing hepatitis E disease. The virus is of one serotype but has diverse genotypes infecting both humans and animals. Based on evidence from seroprevalence studies, about 2 billion people are estimated to have been infected with HEV globally. HEV, therefore, poses a significant public health and economic challenge worldwide. HEV was discovered in the 1980s and was traced back to the 1955 - 1956 outbreak of hepatitis that occurred in India. Subsequently, several HEV epidemics involving thousands of individuals have occurred nearly annually in different countries in Asia and Africa. Initially, the virus was thought to be only enterically transmitted, and endemic in developing countries. Due to the environmental hygiene and sanitation challenges in those parts of the world. However, recent studies have suggested otherwise with the report of autochthonous cases in industrialised countries with no history of travel to the so-called endemic countries. Thus, suggesting that HEV has a global distribution with endemicity in both developing and industrialised nations. Studies have also revealed that HEV has multiple risk factors, and modes of transmission as well as zoonotic potentials. Additionally, recent findings have shown that HEV leads to severe disease, particularly among pregnant women. In contrast to the previous narration of a strictly mild and self-limiting infection. Studies have likewise demonstrated chronic HEV infection among immunocompromised persons. Consequent to these recent discoveries, this pathogen is considered a re - emerging virus, particularly in the developed nations. However, despite the growing public health challenges of this pathogen, the burden is still underestimated. The underestimation is often attributed to poor awareness among clinicians and a lack of routine checks for the disease in the hospitals. Thus, leading to misdiagnosis and underdiagnosis. Hence, this review provides a concise overview of epidemiology, diagnosis, and prevention of hepatitis E.

[A case of Guillain-Barré syndrome following hepatitis E virus infection]

An 81-year-old man presented with limb weakness and dysesthesia approximately 10 days after eating pork liver. His neurological examination revealed muscle weakness predominantly centered in the lower limbs and absence of deep tendon reflex, and cerebrospinal fluid analysis showed elevated proteins with normal cell counts. Furthermore, his nerve conduction studies revealed distal motor latency prolongation and decreased motor nerve conduction velocities in the bilateral median, ulnar, tibial, and peroneal nerves. Lastly, serological analysis was performed for hepatitis E virus markers, resulting in a positive result for hepatitis E virus (HEV)-IgA antibody and HEV-RNA. Given all these findings, the patient was diagnosed with acute HEV-associated Guillain-Barré syndrome (GBS), and intravenous immunoglobulin treatment was administered for five days. Following this, muscle weakness and dysesthesia gradually improved. As observed in this report, the number of HEV-associated GBS cases has been increasing over the past several years. Therefore, HEV infection should be considered in GBS patients who have a history of pork consumption or have been suffering from liver dysfunction.

Advanced Research in Porcine Reproductive and Respiratory Syndrome Virus Co-infection With Other Pathogens in Swine

The porcine reproductive and respiratory syndrome virus (PRRSV) is the pathogen causing epidemics of porcine reproductive and respiratory syndrome (PRRS), and is present in every major swine-farming country in the world. Previous studies have demonstrated that PRRSV infection leads to a range of consequences, such as persistent infection, secondary infection, and co-infection, and is common among pigs in the field. In recent years, coinfection of PRRSV and other porcine pathogens has occurred often, making it more difficult to define and diagnose PRRSV-related diseases. The study of coinfections may be extremely suitable for the current prevention and control in the field. However, there is a limited understanding of coinfection. Therefore, in this review, we have focused on the epidemiology of PRRSV coinfection with other pathogens in swine, both in vivo and in vitro.

First molecular detection of hepatitis E virus genome in camel and pig faecal samples in Ethiopia

BACKGROUND

Hepatitis E is an enteric and zoonotic disease caused by hepatitis E virus (HEV) that is mainly transmitted via the faecal-oral route through contaminated food or the environment. The virus is an emerging infectious agent causing acute human infection worldwide. A high seroprevalence of the disease was reported in pregnant women in Addis Ababa, Ethiopia, raising significant public health concern. The presence of HEV specific antibodies were also reported in dromedary camels in the country; however, the infectious virus and/or the viral genome have not been demonstrated to date in animal samples.

METHODS

To address this gap, a total of 95 faecal samples collected from both apparently healthy pigs of uncharacterised types (50 samples) in Burayu and Addis Ababa areas and camels (Camelus dromedarius, 45 samples) in west Hararghe were screened for the presence of HEV genome using universal primers in a fully nested reverse transcription polymerase chain reaction (nRT-PCR). The protocol is capable of detecting HEV in faecal samples from both pigs and camels.

RESULTS

The nRT-PCR detected HEV genes in six (12%) pig faecal samples and one camel sample (2.2%). Therefore, the results indicate that HEV is circulating in both pigs and camels in Ethiopia and these animals and their products could serve as a potential source of infection for humans.

CONCLUSION

The detection of HEV in both animals could raise another concern regarding its public health importance as both animals' meat and camel milk are consumed in the country. Further studies to determine the prevalence and distribution of the virus in different animals and their products, water bodies, food chain, and vegetables are warranted, along with viral gene sequencing for detailed genetic characterisation of the isolates circulating in the country. This information is critically important to design and institute appropriate control and/or preventive measures.

Hepatitis E Virus in People Who Use Crack-Cocaine: A Cross-Sectional Study in a Remote Region of Northern Brazil

People who use crack-cocaine (PWUCC) have numerous vulnerabilities and pose a challenge to health and social assistance services. The exposure to pathogens and risk situations occur differently according to each individual, region and social group. This study identified the presence, genotypes and factors associated with hepatitis E virus (HEV) exposure among a community-recruited cohort of 437 PWUCC in northern Brazil. Epidemiological information was collected through community-based assessments and interviews. Thereafter, blood and fecal samples were collected and tested for HEV using an immunoenzymatic assay, and the genotype was identified by PCR. Logistic regressions were used to identify the risk factors independently associated with exposure to HEV. In total, 79 (18.1%) PWUCC were exposed to HEV: 73 (16.7%) for IgG and six for IgG + IgM. HEV RNA was detected in six fecal samples and in two blood samples from PWUCC with IgM + IgG. Subtype 3c was identified in all of the samples. The factors associated with exposure to HEV were low monthly income, unstable housing (e.g., homelessness), crack-cocaine use ≥40 months, and the shared use of crack-cocaine equipment. The current study provides unique initial insights into HEV status and risk factors among PWUCC in a remote area in Brazil, with diverse implications for urgently improved diagnosis, prevention, and treatment intervention needs.

Seroprevalence of Hepatitis E Virus Infection among Blood Donors in Bulgaria

Hepatitis E virus (HEV) infection is widespread among domestic pigs, industrial swine, and wild boars in Bulgaria. The aim of the current research was to present the HEV seroprevalence among blood donors in Bulgaria. In the present study, 555 blood donors (479 males and 76 females) were enrolled from five districts in the country (Shumen, Pleven, Stara Zagora, Plovdiv, and Sofia districts). All blood samples were tested for anti-HEV IgG using the recomWell HEV IgG ELISA test (Mikrogen GmbH, Neuried, Germany). Each participating donor completed a short, structured, and specific questionnaire to document data on the current study. Anti-HEV IgG positive results were detected in 144 (25.9%) blood donors, including 129 (26.9%) males and 15 (19.7%) females. The established HEV seropositivity was 28.8% (23/80) in Shumen district, 23.2% (22/95) in Pleven district, 27.1% (38/140) in Stara Zagora district, 27.5% (44/160) in Plovdiv district, and 21.3% (17/80) in Sofia district. A high HEV seroprevalence was found for persons who declared that they were general hunters (48.7%; 19/39; p = 0.001) and hunters of wild boars (51.6%; 16/31; p = 0.001). We present the first seroprevalence rates of HEV infection in blood donors from Bulgaria. The results of our research showed high HEV seropositivity among blood donors.

Occurrence of Human Enteric Viruses in Water Sources and Shellfish: A Focus on Africa

Enteric viruses are a diverse group of human pathogens which are primarily transmitted by the faecal-oral route and are a major cause of non-bacterial diarrhoeal disease in both developed and developing countries. Because they are shed in high numbers by infected individuals and can persist for a long time in the environment, they pose a serious threat to human health globally. Enteric viruses end up in the environment mainly through discharge or leakage of raw or inadequately treated sewage into water sources such as springs, rivers, dams, or marine estuaries. Human exposure then follows when contaminated water is used for drinking, cooking, or recreation and, importantly, when filter-feeding bivalve shellfish are consumed. The human health hazard posed by enteric viruses is particularly serious in Africa where rapid urbanisation in a relatively short period of time has led to the expansion of informal settlements with poor sanitation and failing or non-existent wastewater treatment infrastructure, and where rural communities with limited or no access to municipal water are dependent on nearby open water sources for their subsistence. The role of sewage-contaminated water and bivalve shellfish as vehicles for transmission of enteric viruses is well documented but, to our knowledge, has not been comprehensively reviewed in the African context. Here we provide an overview of enteric viruses and then review the growing body of research where these viruses have been detected in association with sewage-contaminated water or food in several African countries. These studies highlight the need for more research into the prevalence, molecular epidemiology and circulation of these viruses in Africa, as well as for development and application of innovative wastewater treatment approaches to reduce environmental pollution and its impact on human health on the continent.

Infection dynamics and persistence of hepatitis E virus on pig farms - a review

Background

Hepatitis E virus (HEV) genotype 3 and 4 is a zoonosis that causes hepatitis in humans. Humans can become infected by consumption of pork or contact with pigs. Pigs are the main reservoir of the virus worldwide and the virus is present on most pig farms.

Main body

Though HEV is present on most farms, the proportion of infected pigs at slaughter and thus the level of exposure to consumers differs between farms and countries. Understanding the cause of that difference is necessary to install effective measures to lower HEV in pigs at slaughter. Here, HEV studies are reviewed that include infection dynamics of HEV in pigs and on farms, risk factors for HEV farm prevalence, and that describe mechanisms and sources that could generate persistence on farms. Most pigs become infected after maternal immunity has waned, at the end of the nursing or beginning of the fattening phase. Risk factors increasing the likelihood of a high farm prevalence or proportion of actively infected slaughter pigs comprise of factors such as farm demographics, internal and external biosecurity and immunomodulating coinfections. On-farm persistence of HEV is plausible, because of a high transmission rate and a constant influx of susceptible pigs. Environmental sources of HEV that enhance persistence are contaminated manure storages, water and fomites.

Conclusion

As HEV is persistently present on most pig farms, current risk mitigation should focus on lowering transmission within farms, especially between farm compartments. Yet, one should be aware of the paradox of increasing the proportion of actively infected pigs at slaughter by reducing transmission insufficiently. Vaccination of pigs may aid HEV control in the future.

Towards the Improved Accuracy of Hepatitis E Diagnosis in Vulnerable and Target Groups: A Global Perspective on the Current State of Knowledge and the Implications for Practice

The hepatitis E virus (HEV) is a positive single-stranded, icosahedral, quasi-enveloped RNA virus in the genus Orthohepevirus of the family Hepeviridae. Orthohepevirus A is the most numerous species of the genus Orthohepevirus and consists of eight different HEV genotypes that can cause infection in humans. HEV is a pathogen transmitted via the fecal-oral route, most commonly by consuming fecally contaminated water. A particular danger is the HEV-1 genotype, which poses a very high risk of vertical transmission from the mother to the fetus. Several outbreaks caused by this genotype have been reported, resulting in many premature births, abortions, and also neonatal and maternal deaths. Genotype 3 is more prevalent in Europe; however, due to the openness of the market, i.e., trade-in animals which represent a natural reservoir of HEV (such as pigs), there is a possibility of spreading HEV infections outside endemic areas. This problem is indeed global and requires increased hygiene measures in endemic areas, which entails special care for pregnant women in both endemic and non-endemic regions. As already highlighted, pregnant women could have significant health consequences due to the untimely diagnosis of HEV infection; hence, this is a population that should be targeted with a specific combination of testing approaches to ensure optimal specificity and sensitivity. Until we advance from predominantly supportive treatment in pregnancy and appraise the safety and efficacy of a HEV vaccine in this population, such screening approaches represent the mainstay of our public health endeavors.

Hepatitis E should be a global public health priority: recommendations for improving surveillance and prevention

INTRODUCTION

Hepatitis E virus (HEV) is an important cause of enterically transmitted viral hepatitis and a significant contributor to maternal mortality in endemic regions around the world, yet the global response has been limited. HEV is a disease of poverty, and the populations experiencing the greatest burden of HEV-associated illness are not benefitting from existing interventions, including WASH strategies and immunization.

AREAS COVERED

Though a vaccine exists (HEV 239, Hecolin®, Xiamen Innovax Biotech, China), it is only licensed and available in the private market in China and has yet to be prequalified by the WHO for use in endemic settings and outbreaks. This review of the current state of HEV disease and subsequent recommendations for a coordinated public health response are intended to guide the global health community towards breaking the current 'vicious cycle,' in which a lack of data prevents actions that would improve health outcomes.

EXPERT OPINION

Vaccine implementation in future outbreaks, targeted studies assessing vaccine effectiveness and immunogenicity in endemic regions and populations, improved understanding of the global burden, and improvements in diagnostic and epidemiologic tools are urgently needed. Strategies for implementing routine vaccination programs, improving water, sanitation, and hygiene in endemic regions.

Circulating non-coding RNAs as potential diagnostic biomarkers in liver diseases

The liver plays a principal role in the human body as a metabolic and detoxifying unit. Liver diseases are the world's major health problems and affect millions of people worldwide. Early detection of liver diseases is certainly effective in timely treatment and prevention of their progression. Liver injury is associated with significant alterations in immune responses and pattern changes in various tissue-related gene expressions and cytokine production. Increasing or decreasing the specific spectrum of non-coding RNAs in different phases of liver disease can be a criterion for diagnosis. Novel diagnostic biomarkers are needed for liver diseases. Currently, micro-RNAs (miRNAs) are known to play important roles in the diagnosis of liver diseases. Circulating biomarkers such as miRNA-assisted diagnosis can conceivably be helpful for the early treatment of liver diseases. In this review, we look at miRNAs and their potential applications in liver diseases as diagnostic biomarkers were investigated.

The global trends and regional differences in incidence of HEV infection from 1990 to 2017 and implications for HEV prevention

BACKGROUND/AIMS

Hepatitis E virus (HEV) infection is an important cause of acute viral hepatitis worldwide, but it is long-neglected. We aimed to understand the global trends and regional differences in the incidence of HEV infection, thereby making global tailored prevention strategies.

METHODS

This study is a post-hoc analysis of the data from Global Burden of Disease Study 2017. Annual HEV incident cases and incidence rates from 1990 to 2017 were collected. Changes in incident cases and estimated annual percentage changes (EAPCs) of age-standardized incidence rates (ASRs) were calculated to quantify the temporal trends of HEV infection.

RESULTS

Globally, HEV ASRs decreased by an average 0.16% (95% CI: 0.14%-0.17%) per year from 279.79 per 100 000 in 1990 to 269.70 per 100 000 in 2017; however, the number of HEV incident cases increased by 17.63% from 16.53 million in 1990 to 19.44 million in 2017. Against the global trend of ASR falling, an increasing trend was reported in Oceania (EAPC = 0.03; 95% CI: 0.03-0.04) and Western Europe (EAPC = 0.02; 95% CI: 0.01-0.03). The number of HEV incident cases increased remarkably in low (63.07%) and low-middle (37.46%) Socio-Demographic Index (SDI) regions between 1990 and 2017. Additionally, the number of HEV incident cases increased by 4.63% in high SDI regions, mainly in 40 plus age group. Surprisingly, more than 40% of HEV incident cases in Western Europe in 2017 were over 40 years old.

CONCLUSIONS

HEV is still pending in hyperendemic regions, and it is emerging in low endemic regions, suggesting more efforts should be done to make targeted prevention strategies.

Current Paradigm of Hepatitis E Virus Among Pediatric and Adult Patients

Hepatitis E virus (HEV) infection is a polymorphic condition, present throughout the world and involving children and adults. Multiple studies over the last decade have contributed to a better understanding of the natural evolution of this infection in various population groups, several reservoirs and transmission routes being identified. To date, acute or chronic HEV-induced hepatitis has in some cases remained underdiagnosed due to the lower accuracy of serological tests and due to the evolutionary possibility with extrahepatic manifestations. Implementation of diagnostic tests based on nucleic acid analysis has increased the detection rate of this disease. The epidemiological and clinical features of HEV hepatitis differ depending on the geographical areas studied. HEV infection is usually a self-limiting condition in immunocompetent patients, but in certain categories of vulnerable patients it can induce a sudden evolution toward acute liver failure (pregnant women) or chronicity (immunosuppressed patients, post-transplant, hematological, or malignant diseases). In acute HEV infections in most cases supportive treatment is sufficient. In patients who develop chronic hepatitis with HEV, dose reduction of immunosuppressive medication should be the first therapeutic step, especially in patients with transplant. In case of unfavorable response, the initiation of antiviral therapy is recommended. In this review, the authors summarized the essential published data related to the epidemiological, clinical, paraclinical, and therapeutic aspects of HEV infection in adult and pediatric patients.

Review of Hepatitis E Virus in Rats: Evident Risk of Species Orthohepevirus C to Human Zoonotic Infection and Disease

Hepatitis E virus (HEV) (family Hepeviridae) is one of the most common human pathogens, causing acute hepatitis and an increasingly recognized etiological agent in chronic hepatitis and extrahepatic manifestations. Recent studies reported that not only are the classical members of the species Orthohepevirus A (HEV-A) pathogenic to humans but a genetically highly divergent rat origin hepevirus (HEV-C1) in species Orthohepevirus C (HEV-C) is also able to cause zoonotic infection and symptomatic disease (hepatitis) in humans. This review summarizes the current knowledge of hepeviruses in rodents with special focus of rat origin HEV-C1. Cross-species transmission and genetic diversity of HEV-C1 and confirmation of HEV-C1 infections and symptomatic disease in humans re-opened the long-lasting and full of surprises story of HEV in human. This novel knowledge has a consequence to the epidemiology, clinical aspects, laboratory diagnosis, and prevention of HEV infection in humans.

Prevalence and risks of hepatitis E virus infection in blood donors from the Western Cape, South Africa

BACKGROUND

Transfusion-transmitted hepatitis E virus (HEV) infection is a potential risk to recipients of blood transfusions. Infection with HEV poses a high risk to immunocompromised recipients with an increased likelihood of developing chronic infection. The aims of this study were to determine the prevalence of past and active HEV infections in donors from the Western Cape and to identify the risk factors associated with infection.

MATERIALS AND METHODS

We prospectively tested 10 250 blood donors for HEV infection. A risk factor sub-study investigated 250 donors who completed a questionnaire, and plasma samples were tested for HEV IgG antibodies and pooled for HEV RNA detection. The demographic and risk factors associated with HEV infection were assessed. The molecular study tested 10 000 individual donations using a commercial assay to detect viraemia. HEV viral load and genotype were also determined.

RESULTS

The overall anti-HEV IgG seroprevalence was 42·8% (107/250) among donors participating in the risk factor sub-study. The likelihood of past HEV infection was higher with an increase in age. Of the 10 000 donor samples individually tested for HEV RNA, one sample was positive with a viral load of 7·9 x 10⁴ IU/ml and belonged to HEV genotype 3.

CONCLUSION

We found a high seroprevalence of anti-HEV IgG but a low HEV RNA prevalence among donors in the Western Cape, South Africa. The study provides evidence for a potential risk of HEV contamination in the blood supply in South Africa. A cost-benefit analysis is needed before considering the introduction of routine donor screening in our setting.

Evaluation of a non-invasive screening approach to determine hepatitis E virus status of pig farms

BACKGROUND

Identifying pig farms infected with hepatitis E virus (HEV) is a key aspect to implement surveillance programmes for this emerging zoonotic agent. Detection of HEV in blood has several drawbacks, including animal handling, economic costs and animal stress. The objective of this study was to evaluate the effectiveness of a non-invasive screening approach for determining the HEV status of pig farms under different management systems.

METHODS

Forty stool samples randomly collected from the pen floor of 17 intensive pig farms and the yard of nine extensive ones were tested for HEV RNA. The invasive method used to confirm the HEV status of the farm was HEV RNA analysis of serum samples randomly collected from 40 animals on each farm.

RESULTS

Twenty-one HEV-positive farms were detected by invasive and non-invasive methods. No positive serum or stool samples were detected on five intensive farms. A high intertest agreement (K=1; P<0.00001) was observed between both methodologies, showing the stool screening approach a 100 per cent of sensitivity and specificity with respect to the invasive method. Likewise, a significant negative relationship was observed between the HEV within-farm prevalence and the number of the first HEV-positive stool sample found (Spearman's rho=-0.64; P=0.0004). This negative relationship was higher in intensively managed farms.

CONCLUSION

This non-invasive screening approach could be reliably applied in a large-scale surveillance programme for determining the HEV status of pig farms under different management systems.

Assessment of the Presence of Hepatitis E virus in Surface Water and Drinking Water in Portugal

Hepatitis E virus (HEV) is a non-enveloped single-stranded positive-sense RNA virus, belonging to the Hepeviridae family, resistant to environmental conditions, and transmitted by the consumption of contaminated water. This virus is responsible for both sporadic and epidemic outbreaks, leading to thousands of infections per year in several countries, and is thus considered an emerging disease in Europe and Asia. This study refers to a survey in Portugal during 2019, targeting the detection and eventual quantification of enteric viruses in samples from surface and drinking water. Samples positive for HEV RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR), in both types of matrix. The infectivity of these samples was evaluated in cultured Vero E6 cells and RNA from putative viruses produced in cultures evidencing cytopathic effects and was subjected to RT-qPCR targeting HEV genomic RNA. Our results evidenced the existence of samples positive either for HEV RNA (77.8% in surface water and 66.7% in drinking water) or for infectious HEV (23.0% in surface water and 27.7% in drinking water). These results highlight the need for effective virological control of water for human consumption and activities.

Detection and genomic characterization of hepatitis E virus genotype 3 from pigs in Ghana, Africa

BACKGROUND

Hepatitis E virus (HEV) is a major cause of human hepatitis worldwide. Zoonotic genotypes of the virus have been found in diverse animal species with pigs playing a major role. Putative risk of zoonotic infection from livestock particularly swine in Sub-Saharan Africa including Ghana is poorly understood due to scarcity of available data, especially HEV sequence information.

METHODS

Serum samples were collected from cattle, sheep, goats and pigs from Kumasi in the Ashanti region of Ghana. Samples were subjected to nested RT-PCR screening and quantification of HEV RNA-positive samples using real-time RT-PCR and the World Health Organization International Standard for HEV. Testing of all pig samples for antibodies was done by ELISA. Sanger sequencing and genotyping was performed and one representative complete genome was generated to facilitate genome-wide comparison to other available African HEV sequences by phylogenetic analysis.

RESULTS

A total of 420 samples were available from cattle (n = 105), goats (n = 124), pigs (n = 89) and sheep (n = 102). HEV Viral RNA was detected only in pig samples (10.1%). The antibody detection rate in pigs was 77.5%, with positive samples from all sampling sites. Average viral load was 1 × 10⁵ (range 1.02 × 10³ to 3.17 × 10⁵) International Units per mL of serum with no statistically significant differences between age groups (≤ 6 month, > 6 months) by a T-test comparison of means (t = 1.4272, df = 7, p = 0.1966). Sequences obtained in this study form a monophyletic group within HEV genotype 3. Sequences from Cameroon, Ghana, Burkina Faso and Madagascar were found to share a most recent common ancestor; however this was not the case for other African HEV sequences.

CONCLUSION

HEV genotype 3 is highly endemic in pigs in Ghana and likely poses a zoonotic risk to people exposed to pigs. HEV genotype 3 in Ghana shares a common origin with other virus strains from Sub-Saharan Africa.

Methyltransferase of a cell culture-adapted hepatitis E inhibits the MDA5 receptor signaling pathway

Hepatitis E virus (HEV) is a causative agent of acute hepatitis and jaundice. The number of human infections is approximated to be over 20 million cases per year. The transmission is mainly via the fecal-oral route and contaminated water and food are considered to be a major source of infection. As a mouse model is not available, a recent development of a cell culture-adapted HEV strain (47832c) is considered as a very important tools for molecular analysis of HEV pathogenesis in cells. Previously, we demonstrated that HEV-encoded methyltransferase (MeT) encoded by the 47832c strain inhibits MDA5- and RIG-I-mediated activation of interferon β (IFN-β) promoter. Here, we report that MeT impairs the phosphorylation and activation of interferon regulatory factor 3 and the p65 subunit of NF-κB in a dose-dependent manner. In addition, the MeT encoded by the 47832c, but not that of HEV clinical or field isolates (SAR-55, Mex-14, KC-1, and ZJ-1), displays the inhibitory effect. A deeper understanding of MeTmediated suppression of IFN-β expression would provide basis of the cell culture adaptation of HEV.

Why all blood donations should be tested for hepatitis E virus (HEV)

Background

Hepatitis E is a liver disease caused by a small RNA virus known as hepatitis E virus (HEV). Four major genotypes infect humans, of which genotype 1 and 2 (HEV-1, HEV-2) are endemic mainly in Asia and responsible for waterborne epidemics. HEV-3 and HEV-4 are widely distributed in pigs and can be transmitted to humans mainly by undercooked meat, and contact with pigs. HEV-3 is the main genotype in industrialised countries with moderate climate conditions and object of this debate.

Main text

Whereas an HEV-3 infection in healthy humans is mostly asymptomatic, HEV-3 can induce chronic infection in immunocompromised individuals and acute-on-chronic liver failure (ACLF) in patients with underlying liver diseases. The number of reported cases of HEV-infections in industrialised nations increased significantly in the last years. Since HEV-3 has been transmitted by blood transfusion to other humans, testing of blood donors has been introduced or introduction is being discussed in some industrialised countries. In this article we summarise the arguments in favour of testing all blood donations for HEV-3.

Conclusion

The number of HEV infection in the population and the possibility of HEV transmission by blood transfusion are increasing. Transmission by blood transfusion can be dangerous for the recipients considering their immunosuppressive status, underlying disease or other circumstances requiring blood transfusion. This argues in favour of testing all blood donations for HEV-3 to prevent transmission.