First detection of hepatitis E virus in Central Argentina: environmental and serological survey

Prevalence of hepatitis E in Latin America and the Caribbean: A systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence of hepatitis E virus (HEV) infection by the presence of anti-HEV IgG antibodies in Latin America and the Caribbean (LAC).

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Systematic searches were conducted in the Medline, Lilacs and Embase databases, selecting 81 studies comprising 38,951 individuals in accordance with the PRISMA Statement. Analyses were performed by using the random-effects model. Data analysis considered study cohort and geographic location.

RESULTS

The prevalence of hepatitis E in LAC ranged from 0 % to 36 % and the overall prevalence was 9.0 %, with important heterogeneity (I2 = 97.3 %). Meta-analysis of subgroups showed prevalence of hepatitis E of 9.0 % in the general population, 6.0 % in blood donors, 9.0 % in rural population, 21.0 % in occupational exposure to pigs, 9.0 % in pregnant women, 7.0 % in immunocompromised individuals, 12.0 % in individuals with chronic liver disease and 9.0 % in individuals with acute hepatitis. According to geographic location, the prevalence of hepatitis E was 7.0 % in Argentina, 16.0 % in Bolivia, 7.0 % in Brazil, 17.0 % in Colombia and 24.0 % in Cuba. The generated funnel plot appeared asymmetric, with evidence of bias according to Egger (p = 0.000) and Begg (p = 0.003) tests. In the analysis, which included only studies with a quality score >5, the prevalence of hepatitis E was 8.0 %. When analysing studies with sample sizes greater than 200 and 500, we identified prevalences of 8.0 % and 7.0 %, respectively.

CONCLUSIONS

The information obtained in this review warns about the current consolidated prevalence of hepatitis E in LAC, which can be a tool for planning prevention strategies.

Integrated hepatitis e virus monitoring in central Argentina: a six-year analysis of clinical surveillance and wastewater-based epidemiology

Wastewater-based epidemiology (WBE) has gained prominence worldwide as a powerful tool in public health. This study aimed to monitor the circulation of Hepatitis E Virus (HEV) from wastewater samples collected during a six-year period and compare these results with clinical surveillance in the central region of Argentina. From 2017 to 2022, 1008 raw wastewater samples were analyzed, including four wastewater treatment plants from four cities (n=319), and 7 local neighborhood collector sewers in Córdoba city (n=689). Serum and/or stool samples from patients suspected of HEV infection were also analyzed (n=48). HEV molecular detection and viral load quantification were performed by real time RT-qPCR, and genetic characterization by two RT-Nested PCRs (targeting partial ORF-1 and ORF-2 genomic regions), sequencing and phylogenetic analysis. Fifty-three (5.3%) wastewater samples were RNA-HEV positive by real time RT-qPCR, with variations according to the location and year (0.0% - 21.6%). Out of these, ORF-2 genomic region was amplified in 20 samples (37.7%) and ORF-1 partial region in 12 (22.6%), and eighteen sequences were obtained. Throughout the study period, two (4.2%) HEV confirmed infections were reported, and one sequence was obtained. Phylogenetic analyses for both genomic regions showed that all the isolates were genotype HEV-3 clade abchijklm. Our study detected HEV in wastewater over a six-year period, despite a low number of clinical cases, emphasizing WBE as a valuable tool that complements clinical surveillance, by detecting pathogens' presence; identifying their transmission, circulation dynamics and excretion hotspots; and revealing changes in their genomic diversity.

The first detection of mpox virus DNA from wastewater in China

Wastewater monitoring may be a valuable early surveillance tool for studying mpox virus (MPXV) circulation in China, a country with high population density and very few mpox patients. To evaluate the effectiveness of wastewater monitoring for MPXV in detecting local hidden transmission of the epidemic in the early period, the Chinese Center for Disease Control and Prevention initiated a wastewater monitoring program for MPXV in China in July 2023. To enhance the monitoring sensitivity of the program, an MPXV monitoring point was established in a gathering place of high-risk mpox population. Three different concentration methods, PEG precipitation, ultrafiltration, and magnetic beads method were evaluated and compared. Due to its high recovery efficiency, low limit of detection, and high degree of automation, the magnetic beads method was selected for the daily surveillance of MPXV in wastewater. On September 5, 2023, MPXV DNA was detected at the MPXV monitoring point in Zibo City, marking the first instance of MPXV detection of MPXV in wastewater in China. Next-generation sequencing was conducted on the MPXV genome obtained from the positive wastewater, positive environmental samples, and the single case of mpox in Zibo in September. The results showed that the genotypes of these three genomes were different but all belong to the IIb branch of the C.1 lineage, indicating a probably hidden transmission of mpox. Wastewater monitoring is potentially an effective early surveillance tool for tracking the spread of MPXV in areas with high population density and very few mpox patients.

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.

High circulation of hepatitis E virus (HEV) in pigs from the central region of Argentina without evidence of virus occurrence in pork meat and derived products

Hepatitis E virus (HEV) is an emerging cause of viral hepatitis and pigs are considered a reservoir for the virus. HEV genotype 3 (HEV-3) has been reported in pigs, environmental matrices, and sporadic human cases in Argentina. We aimed to investigate HEV circulation in pigs from central Argentina and to assess the virus presence in pork meat and food products. Four types of samples obtained or derived from pigs collected in Córdoba province (Argentina) between 2019 and 2022, were tested: 276 serum samples were analyzed for anti-HEV antibody detection; stool (n = 20), pork meat (n = 71), and salami (n = 76) samples were studied for RNA-HEV detection, followed by sequencing and phylogenetic analyses. The positivity rate for anti-HEV antibodies was 80.1% (221/276). Eleven fecal samples (11/20) tested positive for RNA-HEV, from animals under 120 days of age. Three samples could be sequenced, and phylogenetic analyses revealed that they belonged to HEV-3 clade abchijklm, clustering close to strains previously detected in wastewater from Córdoba. None of the muscle meat or salami samples tested positive. A high HEV circulation in pigs was found, showing that these animals may play a significant role in the viral maintenance in the region, becoming a potential risk to the exposed population. Despite not detecting RNA-HEV in pork meat and salami in our study, we cannot rule out the possibility of foodborne transmission in Córdoba province.

Exploring hepatitis E virus seroprevalence and associated risk factors among the human population in Tandil, Buenos Aires, Argentina

Background

Hepatitis E virus (HEV) infection is a common cause of acute clinical hepatitis worldwide and is emerging as a disease in Argentina. It is primarily transmitted through contaminated water and food, following the fecal-oral route. Furthermore, is a zoonotic disease with swine as the primary reservoir. Prevalence of HEV infection in humans in several regions of Argentina remains unknown.

Objectives

(i) Determine the seroprevalence of HEV among the human population in Tandil, Buenos Aires, Argentina; (ii) Evaluate its association with demographic, socioeconomic and other risk exposures variables, and (iii) Describe and analyze spatial patterns related to HEV infection.

Methods

From August 2020 to July 2021, serum samples were collected from 969 individuals aged 1-80 years. Seroprevalence and 95% Confidence Interval was determined. To assess the factors associated with the presence of anti-HEV antibodies, associations between the variables and seropositivity were evaluated through bivariate and multivariate analysis. Spatial scanning for clusters of positivity was carried out. Factors associated with these clusters were also assessed.

Results

Anti-HEV antibodies were detected in 4.64% (IC 95% 3.27-6.02) of samples. Dark urine was associated with seropositivity (p = 0.02). Seropositivity was linked with the presence of natural water courses near their households (p = 0.02); the age (p = 0.04); and previous travel to Europe (p = 0.04). A spatial cluster of low rates of HEV seropositivity was detected, with greater distance of the households to water courses associated to the cluster, and male sex inversely associated to it.

Discussion and conclusion

This study is the first study to investigate the prevalence of HEV in the population from Tandil, Buenos Aires, Argentina. Considering HEV infection in the differential diagnosis in individuals presenting acute hepatitis is highlighted. The incorporation of HEV testing into blood screening policies should be mandatory. Factors related to the infection and spatial patterns of high and low risk were determined, and should be considered when implementing specific preventive measures.

Tracing the History of Hepatitis E Virus Infection in Mexico: From the Enigmatic Genotype 2 to the Current Disease Situation

Hepatitis E virus (HEV) is the major cause of acute viral hepatitis worldwide. This virus is responsible for waterborne outbreaks in low-income countries and zoonosis transmission in industrialized regions. Initially, considered self-limiting, HEV may also lead to chronic disease, and evidence supports that infection can be considered a systemic disease. In the late 1980s, Mexico became a hot spot in the study of HEV due to one of the first virus outbreaks in Latin America related to enterically transmitted viral non-A, non-B hepatitis. Viral stool particles recovered from Mexican viral hepatitis outbreaks represented the first identification of HEV genotype (Gt) 2 (Gt2) in the world. No new findings of HEV-Gt2 have been reported in the country, whereas this genotype has been found in countries on the African continent. Recent investigations in Mexico have identified other strains (HEV-Gt1 and -Gt3) and a high frequency of anti-HEV antibodies in animal and human populations. Herein, the potential reasons for the disappearance of HEV-Gt2 in Mexico and the advances in the study of HEV in the country are discussed along with challenges in studying this neglected pathogen. These pieces of information are expected to contribute to disease control in the entire Latin American region.

High prevalence of hepatitis A and E viruses in environmental and clinical samples from West Argentina

Environmental surveillance of water sources is important to monitoring viral hepatitis transmission in clinical settings. This study investigated the circulation of hepatitis A (HAV) and E (HEV) viruses in sewage and clinical samples from Argentina. Between 2016 and 2017, 80 raw sewage samples and 86 clinical samples (stool and serum) from suspected cases of hepatitis A and hepatitis E were obtained. HAV and HEV were tested by both real-time and nested PCR. Positive samples were sequenced for genotype determination and phylogenetic analysis. Overall, HAV was recovered in 39% of sewage samples and 61.1% of clinical samples. HEV was detected in 22.5% of sewage samples and 15.9% of clinical samples. HAV was found more frequently in sewage during the winter and in clinical samples in spring; HEV was more prevalent in sewage during summer and in clinical samples in autumn. All HAV isolates belonged to genotype IA and HEV isolates belonged to genotype 3, the most prevalent genotypes in South America. High prevalence of HAV and HEV in environmental and clinical samples in Mendoza, Argentina was observed. These findings reinforce the importance of environmental surveillance and implementation of health strategies to control the spread of HAV and HEV in developing countries.

Quantifying the relationship between sub-population wastewater samples and community-wide SARS-CoV-2 seroprevalence

Robust epidemiological models relating wastewater to community disease prevalence are lacking. Assessments of SARS-CoV-2 infection rates have relied primarily on convenience sampling, which does not provide reliable estimates of community disease prevalence due to inherent biases. This study conducted serial stratified randomized samplings to estimate the prevalence of SARS-CoV-2 antibodies in 3717 participants, and obtained weekly samples of community wastewater for SARS-CoV-2 concentrations in Jefferson County, KY (USA) from August 2020 to February 2021. Using an expanded Susceptible-Infected-Recovered model, the longitudinal estimates of the disease prevalence were obtained and compared with the wastewater concentrations using regression analysis. The model analysis revealed significant temporal differences in epidemic peaks. The results showed that in some areas, the average incidence rate, based on serological sampling, was 50 % higher than the health department rate, which was based on convenience sampling. The model-estimated average prevalence rates correlated well with the wastewater (correlation = 0.63, CI (0.31,0.83)). In the regression analysis, a one copy per ml-unit increase in weekly average wastewater concentration of SARS-CoV-2 corresponded to an average increase of 1-1.3 cases of SARS-CoV-2 infection per 100,000 residents. The analysis indicates that wastewater may provide robust estimates of community spread of infection, in line with the modeled prevalence estimates obtained from stratified randomized sampling, and is therefore superior to publicly available health data.

Wastewater Surveillance for Infectious Disease: A Systematic Review

Wastewater surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown to be a valuable source of information regarding SARS-CoV-2 transmission and coronavirus disease 2019 (COVID-19) cases. Although the method has been used for several decades to track other infectious diseases, there has not been a comprehensive review outlining all of the pathogens that have been surveilled through wastewater. Herein we identify the infectious diseases that have been previously studied via wastewater surveillance prior to the COVID-19 pandemic. Infectious diseases and pathogens were identified in 100 studies of wastewater surveillance across 38 countries, as were themes of how wastewater surveillance and other measures of disease transmission were linked. Twenty-five separate pathogen families were identified in the included studies, with the majority of studies examining pathogens from the family Picornaviridae, including polio and nonpolio enteroviruses. Most studies of wastewater surveillance did not link what was found in the wastewater to other measures of disease transmission. Among those studies that did, the value reported varied by study. Wastewater surveillance should be considered as a potential public health tool for many infectious diseases. Wastewater surveillance studies can be improved by incorporating other measures of disease transmission at the population-level including disease incidence and hospitalizations.

Hepatitis E Virus in Water Environments: A Systematic Review and Meta-analysis

Hepatitis E virus (HEV) is responsible for acute hepatitis in humans, through foodborne, zoonotic, and waterborne transmission routes. This study aimed to assess the prevalence of HEV in water matrices. Six categories were defined: untreated and treated wastewater, surface water (river, lake, and seawater), drinking water, groundwater, and other water environments (irrigation water, grey water, reservoir water, flood water, and effluent of pig slaughterhouse). We searched PubMed, Web of Science, Global Index Medicus, and Excerpta Medica Database. Study selection and data extraction were performed by at least two independent investigators. Heterogeneity (I2) was assessed using the χ2 test on the Cochran Q statistic and H parameter. Sources of heterogeneity were explored by subgroup analysis. This study is registered with PROSPERO, number CRD42021289116. We included 87 prevalence studies from 58 papers, 66.4% of which performed in Europe. The overall prevalence of HEV in water was 9.8% (95% CI 6.4-13.7). The prevalence was higher in untreated wastewater (15.1%) and lower in treated wastewater (3.8%) and in drinking water (4.7%). In surface water, prevalence was 7.4%, and in groundwater, the percentage of positive samples, from only one study available, was 8.3%. Overall, only 36.8% of the studies reported the genotype of HEV, with genotype 3 (HEV-3) prevalent (168 samples), followed by HEV-1 (148 sample), and HEV-4 (2 samples). High-income countries were the most represented with 59/87 studies (67.8%), while only 3/87 (3.5%) of the studies were performed in low-income countries. The overall prevalence obtained of this study was generally higher in industrialized countries. Risk of bias was low in 14.9% of the studies and moderate in 85.1%. The results of this review showed the occurrence of HEV in different waters environments also in industrialized countries with sanitation and safe water supplies. While HEV transmission to humans through water has been widely demonstrated in developing countries, it is an issue still pending in industrialized countries. Better knowledge on the source of pollution, occurrence, survival in water, and removal by water treatment is needed to unravel this transmission path.

Hepatitis E virus in blood donors from Argentina: A possible source of viral infection?

BACKGROUND

The hepatitis E virus (HEV) causes acute hepatitis, which can progress to chronicity in immunosuppressed patients. It is transmitted mainly by the fecal-oral or zoonotic routes, but there is current evidence that it can be transmitted by blood transfusions. The objective of the study was to investigate HEV infections in blood donors in Argentina, within the framework of a hemovigilance program.

METHODS

A total of 547 samples from Argentinean blood donors, collected in 2016, 2019 and 2020 was studied for IgG and IgM anti-HEV by ELISA (Diapro) and RNA HEV by RT-real time PCR and RT-Nested-PCR.

RESULTS

The prevalence of IgG anti-HEV was 3.47% (19/547). No significant differences were registered according to the year studied, sex or age. The presence of RNA HEV was observed in 0.18% (1/547) of the donors studied without serological evidence of infection.

CONCLUSIONS

This is the first molecular detection in blood donors from Argentina, showing a molecular prevalence within the range described for RNA-HEV in blood donors from other non-endemic countries, in which immunocompetent RNA-HEV positive donors without serological evidence of infection were identified. The presence of viraemic donors could imply transfusion transmission, which deserves further attention and study.

Seroprevalence of hepatitis E virus infection in the Americas: Estimates from a systematic review and meta-analysis

Background

Hepatitis E virus (HEV) infection is responsible for inflammatory liver disease and can cause severe health problems. Because the seroprevalence of HEV varies within different population groups and between regions of the continent, we conducted a systematic review on the topic in order to provide evidence for targeted prevention strategies.

Methods

We performed a systematic review in PubMed, SCIELO, LILACS, EBSCO, and Cochrane Library and included reports up to 25 May 2021 (PROSPERO registration number: CRD42020173934). We assessed the risk of bias, publication bias, and heterogeneity between studies and conducted a random-effect meta-analysis for proportions using a (binomial-normal) generalized linear mixed model (GLMM) fitted by Maximum Likelihood (ML). We also reported other characteristics like genotype and risk factors.

Results

Of 1212 identified records, 142 fulfilled the inclusion criteria and were included in the qualitative analysis and 132 in the quantitative analysis. Our random-effects GLMM pooled overall estimate for past infection (IgG) was 7.7% (95% CI 6.4%–9.2%) with high heterogeneity (I2 = 97%). We found higher seroprevalence in certain population groups, for example in people with pig related exposure for IgG (ranges from 6.2%–28% and pooled estimate of 13.8%, 95% CI: 7.6%–23.6%), or with diagnosed or suspected acute viral hepatitis for IgM (ranges from 0.3%–23.9% and pooled estimate of 5.5%, 95% CI: 2.0%–14.1%). Increasing age, contact with pigs and meat products, and low socioeconomic conditions are the main risk factors for HEV infection. Genotype 1 and 3 were documented across the region.

Conclusion

HEV seroprevalence estimates demonstrated high variability within the Americas. There are population groups with higher seroprevalence and reported risk factors for HEV infection that need to be prioritized for further research. Due to human transmission and zoonotic infections in the region, preventive strategies should include water sanitation, occupational health, and food safety.

Zoonotic transmission of hepatitis E virus in a pig farmer from Argentina: A case report

Hepatitis E virus (HEV) is a public health concern due to its zoonotic transmission to human, being pigs a highly recognized reservoir. We previously demonstrated HEV genotype 3 infections in pig herds from the highest commercial active region from Argentina. Here, we present a case of acute symptomatic hepatitis E in an elderly man with occupational exposure to pigs who referred regular consumption of pork and sausages. HEV infection in this patient was demonstrated by serological methods, as well as by HEV RNA detection in serum and stool samples using the HEV/MS2 duplex RT-qPCR, formerly optimized in our laboratory. We further detected HEV RNA in pig faeces from the patient´s farm. To confirm the potential role of swine in the transmission, we performed a phylogenetic analysis of all HEV RNA derived from both, the patient and the pig samples. A 303 nt region within the HEV 5 'ORF2 was amplified by nested RT-PCR and subsequently sequenced. Phylogenetic analysis showed that the strains isolated from the farmer and from his pigs presented a nucleotide identity of 100%. These results support the zoonotic transmission of circulating HEV strains and confirm this epidemiological association for the first time in Argentina.

Environmental surveillance of SARS-CoV-2 RNA in wastewater systems and related environments in Wuhan: April to May of 2020

Wastewater-based epidemiology (WBE) has emerged as an effective environmental surveillance tool in monitoring fecal-oral pathogen infections within a community. Congruently, SARS-CoV-2, the etiologic agent of COVID-19, has been demonstrated to infect the gastrointestinal tissues, and be shed in feces. In the present study, SARS-CoV-2 RNA was concentrated from wastewater, sludge, surface water, ground water, sediment, and soil samples of municipal and hospital wastewater systems and related environments in Wuhan during the COVID-19 middle and low risk periods, and the viral RNA copies quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR). From the findings of this study, during the middle risk period, one influent sample and three secondary effluents collected from waste water treatment plant 2, as well as two samples from Jinyintan Hospital wastewater system influent were SARS-CoV-2 RNA positive. One sludge sample collected from Guanggu Branch of Tongji Hospital, which was obtained during the low risk period, was also positive for SARS-CoV-2 RNA. These study findings demonstrate the significance of WBE in continuous surveillance of SARS-CoV-2 at the community level, even when the COVID-19 prevalence is low. Overall, this study can be used as an important reference for contingency management of wastewater treatment plants and COVID-19 prevention and control departments of Wuhan.

Environmental surveillance of SARS-CoV-2 RNA in wastewater systems and related environments in Wuhan: April to May of 2020

Wastewater-based epidemiology (WBE) has emerged as an effective environmental surveillance tool in monitoring fecal-oral pathogen infections within a community. Congruently, SARS-CoV-2, the etiologic agent of COVID-19, has been demonstrated to infect the gastrointestinal tissues, and be shed in feces. In the present study, SARS-CoV-2 RNA was concentrated from wastewater, sludge, surface water, ground water, sediment, and soil samples of municipal and hospital wastewater systems and related environments in Wuhan during the COVID-19 middle and low risk periods, and the viral RNA copies quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR). From the findings of this study, during the middle risk period, one influent sample and three secondary effluents collected from waste water treatment plant 2, as well as two samples from Jinyintan Hospital wastewater system influent were SARS-CoV-2 RNA positive. One sludge sample collected from Guanggu Branch of Tongji Hospital, which was obtained during the low risk period, was also positive for SARS-CoV-2 RNA. These study findings demonstrate the significance of WBE in continuous surveillance of SARS-CoV-2 at the community level, even when the COVID-19 prevalence is low. Overall, this study can be used as an important reference for contingency management of wastewater treatment plants and COVID-19 prevention and control departments of Wuhan.

Proposed approaches for coronaviruses elimination from wastewater: Membrane techniques and nanotechnology solutions

Since the beginning of the third Millennium, specifically during the last 18 years, three outbreaks of diseases have been recorded caused by coronaviruses (CoVs). The latest outbreak of these diseases was Coronavirus Disease 2019 (COVID-19), which has been declared by the World Health Organization (WHO) as a pandemic. For this reason, current efforts of the environmental, epidemiology scientists, engineers, and water sector professionals are ongoing to detect CoV in environmental components, especially water, and assess the relative risk of exposure to these systems and any measures needed to protect the public health, workers, and public, in general. This review presents a brief overview of CoV in water, wastewater, and surface water based on a literature search providing different solutions to keep water protected from CoV. Membrane techniques are very attractive solutions for virus elimination in water. In addition, another essential solution is nanotechnology and its applications in the detection and protection of human and water systems.

Assessment of Microbiological Quality of Fresh Vegetables and Oysters Produced in Buenos Aires Province, Argentina

Fresh vegetables and shellfish are prone to microbial contamination through irrigation or breeding with sewage-polluted waters, as well as by infected food handlers. In this work, we studied the presence of human and bovine polyomaviruses and human norovirus in fresh lettuces, strawberries and oysters produced in Buenos Aires province, Argentina. In oysters, we also investigated F-specific RNA bacteriophages, indicator Escherichia coli (E. coli) and pathogen bacteria of concern (Salmonella spp., Vibrio spp.). Within vegetables, we found viral contamination of human origin given the presence of human-associated polyomaviruses -MCPyV, HPyV6, JCPyV, and SV40- in lettuce and strawberry samples (16 and 10%, respectively), probably coming from irrigation waters and food handling. Among oysters, human (MCPyV, 4.2%) and bovine (BPyV1, 8.4%) polyomaviruses were detected even with low counts of E. coli. Bacteriophages (n = 3) and Salmonella spp. (n = 1) were also found, while Vibrio spp. was not detected. These results may indicate that the contamination in oysters comes from human and animal excreta, probably present in breeding waters. Norovirus was not detected in any food sample. To our knowledge, this is the first description of SV40 in lettuces and MCPyV and BPyV1 in oysters. The detection of different viral contaminants encourages further studies to evaluate the need for including viral indicators in microbiological standards. The identification of possible sources and routes of contamination using viral markers during routine microbiological controls, such as the polyomaviruses used in this work, would be useful to focus attention on the most hazardous stages of the food production chain.

Seroprevalence of hepatitis E virus in Argentinean blood donors

BACKGROUND

Hepatitis E virus (HEV) is the main cause of enteric acute viral hepatitis worldwide. In this epidemiological framework, it has become a threat to blood safety and a relevant issue for blood transfusions. However, there is a paucity of data regarding prevalence of HEV infection. The aim of this study was to determine HEV seroprevalence in blood donors from different regions from Argentina.

MATERIAL AND METHODS

Serum samples from 391 individuals attending five blood donor centers located in different regions from Argentina were analyzed for anti-HEV IgG and anti-HEV IgM.

RESULTS

Overall, anti-HEV IgG was detected in 44 out of 391 (11.3%) samples. HEV prevalence ranged from 5.1 to 20.0% among different country regions. A significant difference in blood donors' age was observed between anti-HEV IgG positive and negative individuals [44 (37-51) vs. 35 (27-43), P < 0.001, respectively]. Anti-HEV IgM was detected in 8 out of 44 (18.2%) anti-HEV IgG positive cases.

CONCLUSION

Anti-HEV IgG was detected in blood donor samples from five analyzed Argentinean regions, highlighting the wide distribution of the virus in the country. HEV prevalence was variable among different regions and significantly higher in older donors. Given the evidence of anti-HEV IgM presence in blood donors, suggesting a potential risk of transfusion-transmitted HEV, screening for HEV in blood units to be used in vulnerable population would be desirable. Molecular studies for detection of viremic donors and donor-recipients follow-up are necessary to certainly determine the risk of transfusion-transmitted HEV in Argentina.

Viral hepatitis update: Progress and perspectives

Viral hepatitis, secondary to infection with hepatitis A, B, C, D, and E viruses, are a major public health problem and an important cause of morbidity and mortality. Despite the huge medical advances achieved in recent years, there are still points of conflict concerning the pathogenesis, immune response, development of new and more effective vaccines, therapies, and treatment. This review focuses on the most important research topics that deal with issues that are currently being solved, those that remain to be solved, and future research directions. For hepatitis A virus we will address epidemiology, molecular surveillance, new susceptible populations as well as environmental and food detections. In the case of hepatitis B virus, we will discuss host factors related to disease, diagnosis, therapy, and vaccine improvement. On hepatitis C virus, we will focus on pathogenesis, immune response, direct action antivirals treatment in the context of solid organ transplantation, issues related to hepatocellular carcinoma development, direct action antivirals resistance due to selection of resistance-associated variants, and vaccination. Regarding hepatitis D virus, we describe diagnostic methodology, pathogenesis, and therapy. Finally, for hepatitis E virus, we will address epidemiology (including new emerging species), diagnosis, clinical aspects, treatment, the development of a vaccine, and environmental surveillance.

Prevalence of hepatitis E virus in children from Northeast of Argentina

The aim of this study was to assess the prevalence of hepatitis E virus (HEV) in a young population from the Northeast region of Argentina. Four hundred and twelve patients under 18 years old, from rural areas of Chaco Province, were tested for anti-HEV immunoglobulin G (IgG) using enzyme-linked immunosorbent assay. Anti-HEV IgG antibodies were detected in 7 out of 412 patients, accounting for an overall 1.7% prevalence. HEV infection in developing countries is associated to lack of clean drinking water. Consequently, the seroprevalence observed in children in rural areas of Chaco, Argentina, where the access to tap water is less than 15%, was unexpectedly low.

Phylogeography and evolutionary history of hepatitis E virus genotype 3 in Argentina

BACKGROUND

Few studies about the evolutionary history of the hepatitis E virus (HEV) have been conducted. The aim of our work was to investigate and make inferences about the origin and routes of dispersion of HEV-3 in Argentina.

METHODS

Phylogenetic, coalescent and phylogeographic analyses were performed using a 322-bp ORF2 genomic fragment of all HEV-3 sequences with known date and place of isolation published at GenBank until May 2018 (n=926), including 16 Argentinian sequences (isolated from pigs, water and humans).

RESULTS

Phylogenetic analysis revealed two clades within HEV-3: abchij and efg. All Argentinian samples were grouped intermingled within clade 3abchij. The coalescent analysis showed that the most recent common ancestor for the clade 3abchij would have existed around the year 1967 (95% highest posterior density (HPD): 1963-1970). The estimated substitution rate was 1.01×10-2 (95%HPD: 9.3×10-3-1.09×10-2) substitutions/site/y, comparable with the rate previously described. The phylogeographic approach revealed a correspondence between phylogeny and place of origin for Argentinian samples, suggesting many HEV introductions in the country, probably from Europe and Japan.

CONCLUSIONS

This is the first evolutionary inference of HEV-3 that includes Argentinian strains, showing the circulation of many HEV-3 subtypes, obtained from different sources and places, with recent diversification processes.

ACCESSION NUMBERS

[KX812460], [KX812461], [KX812462], [KX812465], [KX812466], [KX812467], [KX812468], [KX812469].

Serologic evidence of the circulation of the hepatitis E virus and the prevalence of antibodies against hepatitis A in an indigenous population in northern Argentina

In 2005 a universal vaccination program against hepatitis A was introduced in Argentina. Nevertheless, there are still some unvaccinated marginal population groups. There are no data about the seroprevalence of hepatitis E in the northern region of Argentina mainly because of lack of awareness of this emergent pathogen. We aimed to determine the seroprevalence of hepatitis A, and hepatitis E in an indigenous population in northern Argentina. One hundred and twenty six (126) donor serum samples collected near San Salvador de Jujuy were analyzed for anti-HAV IgG and HEV IgG and IgM, alkaline phosphatase and transaminase values. Volunteers were interviewed about their living conditions, animal farming, consumption of tap water or river water, and level of education. Seroprevalence of specific anti-HAV antibodies was high (80.2%, 95% confidence interval, 72.1-86.7%) in children under 5 years of age, indicating early infection in life. Seroprevalence of anti-HEV antibodies was 5.6% (95% CI: 2.3-11.2%), being slightly higher than the values found in healthy patients from other regions of the country. Although we could not characterize the genotype of the circulating HEV strain, the clear epidemiological difference between seroprevalence of HAV and HEV in a community with poor sanitary conditions suggest that the circulating HEV strains spread through a different transmission route than HAV. Furthermore a significant correlation between anti-HEV IgG and swine farming was found (p<0.05), which supports a zoonotic transmission path. We reassessed the epidemiological pattern of HAV infection and reported evidence of HEV infection for the first-time in a community belonging to the Guarani ethnic group, highlighting the need to include hepatitis E testing in routine diagnostics in the region.

First detection of SARS-CoV-2 in untreated wastewaters in Italy

Several studies have demonstrated the advantages of environmental surveillance through the monitoring of sewage for the assessment of viruses circulating in a given community (wastewater-based epidemiology, WBE). During the COVID-19 public health emergency, many reports have described the presence of SARS-CoV-2 RNA in stools from COVID-19 patients, and a few studies reported the occurrence of SARS-CoV-2 in wastewaters worldwide. Italy is among the world's worst-affected countries in the COVID-19 pandemic, but so far there are no studies assessing the presence of SARS-CoV-2 in Italian wastewaters. To this aim, twelve influent sewage samples, collected between February and April 2020 from Wastewater Treatment Plants in Milan and Rome, were tested adapting, for concentration, the standard WHO procedure for Poliovirus surveillance. Molecular analysis was undertaken with three nested protocols, including a newly designed SARS-CoV-2 specific primer set. SARS-CoV-2 RNA detection was accomplished in volumes of 250 ml of wastewaters collected in areas of high (Milan) and low (Rome) epidemic circulation, according to clinical data. Overall, 6 out of 12 samples were positive. One of the positive results was obtained in a Milan wastewater sample collected a few days after the first notified Italian case of autochthonous SARS-CoV-2. The study confirms that WBE has the potential to be applied to SARS-CoV-2 as a sensitive tool to study spatial and temporal trends of virus circulation in the population.

First detection of SARS-CoV-2 in untreated wastewaters in Italy

Several studies have demonstrated the advantages of environmental surveillance through the monitoring of sewage for the assessment of viruses circulating in a given community (wastewater-based epidemiology, WBE). During the COVID-19 public health emergency, many reports have described the presence of SARS-CoV-2 RNA in stools from COVID-19 patients, and a few studies reported the occurrence of SARS-CoV-2 in wastewaters worldwide. Italy is among the world's worst-affected countries in the COVID-19 pandemic, but so far there are no studies assessing the presence of SARS-CoV-2 in Italian wastewaters. To this aim, twelve influent sewage samples, collected between February and April 2020 from Wastewater Treatment Plants in Milan and Rome, were tested adapting, for concentration, the standard WHO procedure for Poliovirus surveillance. Molecular analysis was undertaken with three nested protocols, including a newly designed SARS-CoV-2 specific primer set. SARS-CoV-2 RNA detection was accomplished in volumes of 250 ml of wastewaters collected in areas of high (Milan) and low (Rome) epidemic circulation, according to clinical data. Overall, 6 out of 12 samples were positive. One of the positive results was obtained in a Milan wastewater sample collected a few days after the first notified Italian case of autochthonous SARS-CoV-2. The study confirms that WBE has the potential to be applied to SARS-CoV-2 as a sensitive tool to study spatial and temporal trends of virus circulation in the population.

Hepatitis E virus infection in pregnant women, Argentina

Background

Hepatitis E virus (HEV) infection is an important cause of acute hepatitis worldwide. In pregnant women, HEV can cause more severe symptoms, with high rates of fatal hepatic failure in endemic countries. However, HEV prevalence and circulation among pregnant women from South America is almost unknown. We aimed to investigate HEV infection in pregnant women for the first time in Argentina.

Methods

IgG and IgM anti-HEV antibodies and RNA-HEV were investigated (by ELISA assays and RT-Nested-PCR, respectively) in 202 serum samples from pregnant women collected in the central region of Argentina between 2015 and 2017. A control group of 155 non-pregnant women was included (year 2018).

Results

The IgG anti-HEV positivity rate was 8.4% (17/202), higher than the 2.6% (4/155) obtained for the non-pregnant women control group, and showing association between pregnancy and HEV infection (p = 0.023, OR = 3.5, CI95% = 1.1–10.5). Women younger than 25 years old presented higher levels of antibodies, and there were no differences in the prevalences between trimesters of pregnancy. Two samples were reactive for IgM anti-HEV, showing recent infections, although no symptoms were registered in these patients. All samples were negative for RNA-HEV amplification.

Conclusions

HEV produces infections in pregnant women from Argentina, alerting health teams to consider it as a possible cause of liver disease.

The study of seroprevalence of hepatitis E virus and an investigation into the lifestyle behaviours of the aborigines in Malaysia

Malaysia is a non-endemic country for hepatitis E virus (HEV) infection. However, seroprevalence as high as 50% among samples of aboriginal people were reported over two decades ago. A total of 207 samples collected from seven aboriginal villages in rural settlements across two states in Malaysia were analysed for anti-HEV IgG and IgM by an enzyme-linked immunoassay. Following the detection of anti-HEV seroprevalence, we organized health outreach to inform and educate the community. Qualitative interviews were conducted with individuals tested positive for anti-HEV antibodies. Data derived from interviews and observations were used to investigate possible lifestyle behaviours associated with HEV infection. Anti-HEV IgG was detected in six samples (5.9%) from the village of Dusun Kubur. Qualitative inquiry and observation study revealed poor dietary and household hygiene, contaminated food and water, contact with animal faeces, unsanitary and domestic waste disposal, and wildlife reservoirs could be the contributing factors for transmission and acquisition of HEV infection. Investigation during health outreach is important to provide insights for future empirical research and implementation for improvement of lifestyle behaviours among the aborigines. Managing the risk of HEV infection in the aborigines may reduce the risk of HEV transmission to the local communities.

Nine-Year Nationwide Environmental Surveillance of Hepatitis E Virus in Urban Wastewaters in Italy (2011-2019)

Hepatitis E virus (HEV) is an emerging causative agent of acute hepatitis worldwide. To provide insights into the epidemiology of HEV in Italy, a large-scale investigation was conducted into urban sewage over nine years (2011-2019), collecting 1374 sewage samples from 48 wastewater treatment plants located in all the 20 regions of Italy. Broadly reactive primers targeting the ORF1 and ORF2 regions were used for the detection and typing of HEV, followed by Sanger and next generation sequencing (NGS). Real-time RT-qPCR was also used to attempt quantification of positive samples. HEV RNA detection occurred in 74 urban sewage samples (5.4%), with a statistically significant higher frequency (7.1%) in central Italy. Fifty-six samples were characterized as G3 strains and 18 as G1. While the detection of G3 strains occurred in all the surveillance period, G1 strains were mainly detected in 2011-2012, and never in 2017-2019. Typing was achieved in 2 samples (3f subtype). Viral concentrations in quantifiable samples ranged from 1.2 × 103 g.c./L to 2.8 × 104 g.c./L. Our results suggest the considerable circulation of the virus in the Italian population, despite a relatively small number of notified cases, a higher occurrence in central Italy, and a noteworthy predominance of G3 strains.

A Novel In-House Enzyme-Linked Immunosorbent Assay for Genotype 3 Hepatitis E Virus Reveals High Seroprevalence in Blood Donors in Northern Argentina

The Hepatitis E virus (HEV) is an emergent virus that causes acute hepatitis in immunocompetent hosts and chronic hepatitis in immunocompromised hosts. In Latin America, the main circulating genotype HEV-3 is usually of zoonotic origin. Diagnosis and seroprevalence studies mainly rely on the detection of specific antibodies. There are scarce data on the seroprevalence of HEV infection in Latin America mainly due to the lack of awareness of HEV circulation. Furthermore, in some countries, like Argentina, HEV testing is not included in routine assays. In order to provide tools to deepen the knowledge on HEV epidemiology in South America, we designed a new in-house ELISA based on the native recombinant protein ORF2 aa112–608 and demonstrated its potential for detecting anti-HEV immunoglobulin G (IgG) in human serum samples. The following conditions were determined: an optimal antigen concentration of 0.25 μg/ml, a serum dilution of 1:80, gelatin as a blocking agent, and a secondary antibody dilution of 1:2000. A relative sensitivity of 93.33% (95% CI: 77.9–99.2%) and a relative specificity of 99.4% (95% CI: 96.7–100%) were determined using a panel of previously characterized sera and a gold standard (HEV IgG ELISA, DIA.PRO, Italy). Further, we obtained a very good agreement (κ index = 0.94, 95% CI: 0.87–1.00) with the gold standard. We screened 813 blood donor samples with this newly developed ELISA and found a seroprevalence of 9.23% (95% confidence interval, 7.33–11.43%). We show for the first time evidence of past HEV infection in Tucuman, the most populated city in northern Argentina. We expect that this study will raise the interest of health decision makers who should intercede to include indirect testing of HEV in regular diagnostic protocols. In conclusion, the in-house ELISA developed in this work shows a very good agreement with an already licensed commercial HEV IgG ELISA (DIA.PRO, ITALY), which can be used as an epidemiologic tool for HEV surveillance.

Unexpected high seroprevalence of hepatitis E virus in patients with alcohol-related cirrhosis

INTRODUCTION

Little is known about hepatitis E virus (HEV) infection in patients with cirrhosis. The aim of the present study was to describe the frequency of HEV infection and associated risk factors in patients with cirrhosis from Argentina.

MATERIALS AND METHODS

We evaluated HEV seroprevalence (IgG anti-HEV) and acute infections (IgM and RNA) in patients with cirrhosis (n = 140) vs. healthy controls (n = 300). Additionally, we compared the same outcomes in individuals with alcohol-related cirrhosis (n = 43) vs. patients with alcohol use disorder (without cirrhosis, n = 72).

RESULTS

The overall HEV seroprevalence in the cohort of subjects with cirrhosis was 25% (35/140), compared to 4% in the healthy control group [12/300; OR = 8; (95% CI = 4-15.99); p<0.05]. HEV seropositivity was significantly higher in alcohol-related cirrhosis compared to other causes of cirrhosis [39.5% vs. 12.4%; OR = 4.71; (95% CI = 1.9-11.6); p<0.05] and to healthy controls [OR = 15.7; (95% CI = 6.8-36.4); p = 0.0001]. The HEV seroprevalence in alcoholic-related cirrhosis vs. with alcohol use disorder was 39.5% vs. 12.5% [OR = 4.58; (95% CI = 1.81-11.58); p<0.001].

CONCLUSION

We found a high seroprevalence of HEV in patients with cirrhosis and in individuals with alcohol use disorder. The simultaneous presence of both factors (cirrhosis + alcohol) showed more association to HEV infection. Larger studies with prospective follow up are needed to further clarify this interaction.

Detection of HEV in naturally infected swine from central Argentina by an optimized HEV/MS2 duplex RT-qPCR

Hepatitis E virus (HEV) is currently considered as a global health concern due to the recognition of its zoonotic transmission to humans, mainly from swine, and its association with the development of severe cases of hepatitis in human risk populations. The lack of updated data on HEV state of infection in swineherds of Argentina, and the necessity of robust technologies for its detection in complex biological samples, positions HEV as an emerging issue in public health. Here, we have optimized a RT-qPCR with internal control for a more precise and accurate HEV RNA detection in swine stool samples. We implemented this optimized molecular tool to analyse the current epidemiological scenario of HEV infection in swine from the core region of commercial activity of Argentina. A total of 135 stool samples were collected from 16 different farms and tested for HEV presence, resulting in 11 positive cases (8.1%). Phylogenetic analysis demonstrated that all of them correspond to HEV genotype 3 and that different subtypes circulate in the region. Moreover, two of the detected strains presented a high nucleotide similarity with a previously identified isolate from human sewage discharges, suggesting the zoonotic transmission of HEV to humans. Collectively, this work provides a better understanding of HEV epidemiology in Argentina while contributes to the improvement of HEV detection technologies.

Environmental hepatitis E virus detection supported by serological evidence in the northwest of Argentina

Background

Hepatitis E virus (HEV) is an emergent cause of acute hepatitis worldwide. Water contamination is a possible source of viral infection. In South America, particularly in Argentina, little is known about environmental HEV circulation, including recreational water. The aim of this work was to provide evidence of current environmental and human circulation of HEV in northern Argentina.

Methods

Molecular detection of HEV in water samples from the Arias-Arenales River in the city of Salta by nested polymerase chain reaction (ORF2 region) and anti-HEV immunoglobulin G (IgG) and IgM detection in the general population by enzyme-linked immunosorbent assay was carried out.

Results

HEV RNA was detected in 1.6% (3/189) of the environmental samples. All sequences belonged to HEV genotype 3 and were very similar to those previously detected in the country. The prevalence of IgG anti-HEV was 9% (13/143) and three samples were positive for specific IgM.

Conclusions

Circulation of HEV in the northwest of Argentina was demonstrated for the first time, showing viral presence in environmental samples and infections in people who attended health care centres for routine control. These findings show that recreational waters are a possible source of virus and highlight the need to carry out HEV detection when a case of hepatitis occurs.

Transmission of hepatitis E virus by water: An issue still pending in industrialized countries

Hepatitis E virus (HEV) is an enteric virus divided into eight genotypes. Genotype 1 (G1) and G2 are specific to humans; G3, G4 and G7 are zoonotic genotypes infecting humans and animals. Transmission to humans through water has been demonstrated for G1 and G2, mainly in developing countries, but is only suspected for the zoonotic genotypes. Thus, the water-related HEV hazard may be due to human and animal faeces. The high HEV genetic variability allows considering the presence in wastewater of not only different genotypes, but also quasispecies adding even greater diversity. Moreover, recent studies have demonstrated that HEV particles may be either quasi-enveloped or non-enveloped, potentially implying differential viral behaviours in the environment. The presence of HEV has been demonstrated at the different stages of the water cycle all over the world, especially for HEV G3 in Europe and the USA. Concerning HEV survival in water, the virus does not have higher resistance to inactivating factors (heat, UV, chlorine, physical removal), compared to viral indicators (MS2 phage) or other highly resistant enteric viruses (Hepatitis A virus). But the studies did not take into account genetic (genogroups, quasispecies) or structural (quasi- or non-enveloped forms) HEV variability. Viral variability could indeed modify HEV persistence in water by influencing its interaction with the environment, its infectivity and its pathogenicity, and subsequently its transmission by water. The cell culture methods used to study HEV survival still have drawbacks (challenging virus cultivation, time consuming, lack of sensitivity). As explained in the present review, the issue of HEV transmission to humans through water is similar to that of other enteric viruses because of their similar or lower survival. HEV transmission to animals through water and how the virus variability affects its survival and transmission remain to be investigated.

Seroprevalence of hepatitis E in adults in Brazil: a systematic review and meta-analysis

BACKGROUND

Hepatitis E virus (HEV) is a member of the Hepeviridae family; it has four main genotypes and one serotype. While genotypes 1 and 2 cause epidemic hepatitis and are transmitted via water and the fecal-oral route, genotypes 3 and 4 are zoonotic. In the various seroprevalence studies of hepatitis E in Brazil, the numbers reported vary widely and are difficult to interpret. The aim of this study was to analyze existing seroprevalence studies of hepatitis E in adults in Brazil.

MAIN TEXT

We searched the PubMed, Latin American and Caribbean Health Sciences and Embase databases for studies published from inception to May 12, 2018 concerning infection by HEV in Brazil without time period or language restrictions. We included studies that presented data concerning hepatitis E seroprevalence in adults in Brazil, had a sample size ≥50 patients and whose method used for the detection of anti-HEV was standardized and commercialized. We also evaluated the quality of the articles using a list of criteria that totalized 9 items. Of the 20 studies ultimately analyzed, 10 (50%) were from the southeast region of Brazil, 3 (15%) were from the central-west region, 3 (15%) were from the northern region, 2 (10%) were from the northeast region and 2 (10%) were from the southern region. Regarding the quality evaluation of the studies, the mean score was 5.6 (range: 4-8). The estimated overall seroprevalence of HEV infection in the adult population was 6.0% (95% CI: 5.0-7.0); in subgroup analyses, we observed that the prevalence of anti-HEV antibodies in blood donors was 7.0% (95% CI: 5.0-8.0), whereas in the general population, it was 3.0% (95% CI: 2.0-4.0).

CONCLUSIONS

The results of this systematic review indicate that there should be national investment in the prevention of hepatitis E virus infection in Brazil, including the implementation of improvements in basic sanitation and guidance regarding the appropriate handling of animal waste and the optimal cooking of vegetables, meat and their derivatives.

Hepatitis E seroprevalence in the Americas: A systematic review and meta-analysis

BACKGROUND & AIMS

While hepatitis E virus infections are a relevant topic in Europe, knowledge about epidemiology of hepatitis E virus infections in the USA and Latin America is still limited. Aim of this study was to estimate anti-hepatitis E virus IgG seroprevalence in the Americas and to assess whether low socioeconomic status is associated with hepatitis E virus exposure.

METHODS

We performed a systematic review and meta-analysis. Literature search was performed in PubMed for articles published 01/1994-12/2016. Prevalence was estimated using a mixed-effects model and reported in line with PRISMA reporting guidelines.

RESULTS

Seroprevalence was significantly higher in the USA than in Latin America, independently of assay, patient cohort, methodological quality or study year (OR: 1.82 (1.06-3.08), P = .03). Patients in the USA had a more than doubled estimated seroprevalence (up to 9%, confidence interval 5%-15.6%) than those in Brazil (up to 4.2%, confidence interval 2.4%-7.1%; OR: 2.27 (1.25-4.13); P = .007) and Mixed Caribbean (up to 1%, OR: 8.33 (1.15-81.61); P = .04). A comparison with published data from Europe demonstrated that anti-hepatitis E virus seroprevalence in the USA and Europe did not differ significantly (OR: 1.33 (0.81-2.19), P = .25), while rate in South America was significantly lower than that in Europe (OR: 0.67 (0.45-0.98), P = .04).

CONCLUSIONS

Hepatitis E virus is common in the USA. Surprisingly, the risk of hepatitis E virus exposure was low in many South American countries. Seroprevalence did not differ significantly between Europe and the USA. Hence, hepatitis E virus is not limited to countries with low sanitary standards, and a higher socioeconomic status does not protect populations from hepatitis E virus exposure.

Tracking enteric viruses in green vegetables from central Argentina: potential association with viral contamination of irrigation waters

Consumption of green vegetable products is commonly viewed as a potential risk factor for infection with enteric viruses. The link between vegetable crops and fecally contaminated irrigation water establishes an environmental scenario that can result in a risk to human health. The aim of this work was to analyze the enteric viral quality in leafy green vegetables from Córdoba (Argentina) and its potential association with viral contamination of irrigation waters. During July-December 2012, vegetables were collected from peri-urban green farms (n = 19) and its corresponding urban river irrigation waters (n = 12). Also, urban sewage samples (n = 6) were collected to analyze the viral variants circulating in the community. Viruses were eluted and concentrated by polyethylene glycol precipitation and then were subject to Reverse Transcription Polymerase Chain Reaction to assess the genome presence of norovirus, rotavirus and human astrovirus. The concentrates were also inoculated in HEp-2 (Human Epidermoid carcinoma strain #2) cells to monitor the occurrence of infective enterovirus. The frequency of detection of the viral groups in sewage, irrigation water and crops was: norovirus 100%, 67% and 58%, rotavirus 100%, 75% and 5%, astrovirus 83%, 75% and 32% and infective enterovirus 50%, 33% and 79%, respectively. A similar profile in sewage, irrigation water and green vegetables was observed for norovirus genogroups (I and II) distribution as well as for rotavirus and astrovirus G-types. These results provide the first data for Argentina pointing out that green leafy vegetables are contaminated with a broad range of enteric viruses and that the irrigation water would be a source of contamination. The presence of viral genomes and infective particles in food that in general suffer minimal treatment before consumption underlines that green crops can act as potential sources of enteric virus transmission. Public intervention in the use of the river waters as irrigation source is needed.

Hiding in Plain Sight? It's Time to Investigate Other Possible Transmission Routes for Hepatitis E Virus (HEV) in Developed Countries

Historically in developed countries, reported hepatitis E cases were typically travellers returning from countries where hepatitis E virus (HEV) is endemic, but now there are increasing numbers of non-travel-related ("autochthonous") cases being reported. Data for HEV in New Zealand remain limited and the transmission routes unproven. We critically reviewed the scientific evidence supporting HEV transmission routes in other developed countries to inform how people in New Zealand may be exposed to this virus. A substantial body of indirect evidence shows domesticated pigs are a source of zoonotic human HEV infection, but there is an information bias towards this established reservoir. The increasing range of animals in which HEV has been detected makes it important to consider other possible animal reservoirs of HEV genotypes that can or could infect humans. Foodborne transmission of HEV from swine and deer products has been proven, and a large body of indirect evidence (e.g. food surveys, epidemiological studies and phylogenetic analyses) support pig products as vehicles of HEV infection. Scarce data from other foods suggest we are neglecting other potential sources of foodborne HEV infection. Moreover, other transmission routes are scarcely investigated in developed countries; the role of infected food handlers, person-to-person transmission via the faecal-oral route, and waterborne transmission from recreational contact or drinking untreated or inadequately treated water. People have become symptomatic after receiving transfusions of HEV-contaminated blood, but it is unclear how important this is in the overall hepatitis E disease burden. There is need for broader research efforts to support establishing risk-based controls.

Hepatitis E virus in South America: The current scenario

Hepatitis E virus (HEV) is one of the most frequent causes of acute viral hepatitis of enteric transmission worldwide. In South America the overall epidemiology has been little studied, and the burden of the disease remains largely unknown. A research of all scientific articles about HEV circulation in South America until November 2017 was carried out. Human seroprevalences of HEV varied according to the studied population: blood donors presented prevalence rates ranging from 1.8% to 9.8%, while reports from HIV-infected individuals, transplant recipients and patients on hemodialysis showed higher prevalence rates. Only 2 cases of chronic hepatitis in solid-organ transplant patients from Argentina and Brazil have been described. Detection of HEV in the swine population is widely prevalent in the region. Anti-HEV antibodies have also been recently documented in wild boars from Uruguay. Although scarce, studies focused on environmental and food HEV detection have shown viral presence in these kind of samples, highlighting possible transmission sources of HEV in the continent. HEV genotype 3 was the most frequently detected in the region, with HEV genotype 1 detected only in Venezuela and Uruguay. HEV is widely distributed throughout South America, producing sporadic cases of acute hepatitis, but as a possible agent of chronic hepatitis. Finding the virus in humans, animals, environmental samples and food, show that it can be transmitted through many sources, alerting local governments and health systems to improve diagnosis and for the implementation of preventive measures.

Enteric Viruses in Surface Waters from Argentina: Molecular and Viable-Virus Detection

Water resources contaminated with wastewater are an important source for the dissemination of enteric viruses with an impact on the health of the population. The aim of the study was to assess the viral contamination of freshwater from a dam in Argentina by using infectious enterovirus detection, viral RNA amplification, and a genetic characterization of five enteric viruses associated with diarrhea and hepatitis. Enterovirus infectivity (iEV) was evaluated by cell culture and direct immunofluorescence. The detection of the viral genome of rotavirus (RV), human astrovirus (HAstV), norovirus (NoV), hepatitis A virus (HAV), and hepatitis E virus (HEV) was performed by reverse transcriptase PCR (RT-PCR). A total of 48 water samples from 4 monitoring points on the body of the dam from January to December 2012 and 66 water samples from 3 tourist beaches on the edge of the dam from October 2013 to October 2015 were collected monthly. During the first period, the overall viral frequency detection was 52.1% for group A RV, 50% for HAstV, 60.4% for NoV, 22.9% for HAV, 2.1% for HEV, and 64.6% for iEV. The overall frequency detection for the second sampling was 18.2% for RV and HAstV, 31.8% for NoV, 7.57% for HEV, and 66.7% for iEV. There was no detection of HAV during this period. The genotypes and genogroups detected through the study correlated with the most common genomic variants associated with human gastrointestinal and hepatitis illnesses. The results obtained could alert the health systems and environmental sanitation to make decisions for viral control and prevention in our environment.IMPORTANCE The study shows the impact of anthropic contamination of one of the most important tourist water resources in Argentina. This course of recreational water would be a favorable scenario for infection, as well as a reservoir for the enteric viruses, creating a risk for the population exposed to these waters. The results obtained could alert the health systems and environmental sanitation to make decisions for the control and prevention of viral diseases in this environment.

Hepatitis E: Update on Prevention and Control

Hepatitis E virus (HEV) is a common etiology of acute viral hepatitis worldwide. Recombinant HEV vaccines have been developed, but only one is commercially available and licensed in China since 2011. Epidemiological studies have identified genotype 3 as the major cause of chronic infection in immunocompromised individuals. Ribavirin has been shown to be effective as a monotherapy to induce HEV clearance in chronic patients who have undergone solid organ transplant (SOT) under immunosuppressive therapy. Efforts and improvements in prevention and control have been made to reduce the instances of acute and chronic hepatitis E in endemic and nonendemic countries. However, this review shows that further studies are required to demonstrate the importance of preventive vaccination and treatment worldwide, with emphasis on hepatitis E infection in the public health system.

First evidence of the Hepatitis E virus in environmental waters in Colombia

Hepatitis E virus (HEV) is one of the main causes of acute viral hepatitis of enteric transmission. HEV has been detected in environmental samples in several countries from Europe and Asia, constituting a risk factor for waterborne infection. In Colombia, HEV has been identified in samples obtained from patients as well as from swine, but no environmental studies have been carried out. To determine if HEV is present in environmental waters, samples from the main source of drinking water plant and of wastewater system of eight municipalities and two villages of Antioquia state (North West Colombia), were collected between December 2012 and April 2014. The HEV genome was detected by RT-PCR in 23.3% (7/30) of the samples from the main source of drinking water plants and in 16.7% (5/30) from sewage. Viral concentrates obtained from three positive sewage samples were used to inoculate HepG2 cell cultures that were followed for one month; however, the viral genome was not detected in any cell culture. This study demonstrates the circulation of HEV in both source of drinking water plants and wastewater in Antioquia state, Colombia. The presence of HEV in environmental waters could be a risk for waterborne transmission in this population. The findings of the present study, together with the evidence of HEV circulation in human and swine in Colombia, should be consider by public health authorities for the development of surveillance programs and the inclusion of HEV infection diagnosis in the guidelines of viral hepatitis in the country. This is the first report of HEV in environmental samples in Colombia and the second one in Latin America.

A novel subgenotype 3a hepatitis E virus isolated from pigs in China

Hepatitis E virus (HEV) infection is an emerging disease with zoonotic transmission that represents a serious public health concern, especially in developing countries. Here we characterize a novel HEV strain CCST-517, which possesses a complete genome sequence of 7284 bp with typical HEV genome organization including 5' and 3' non-coding regions and three open reading frames. The sequence identities of CCST-517 with known HEV genotype 1, 2, 3, and 4 were 73.4-73.7, 73.2, 80.4-90.4, and 75.1-75.7%, respectively. Phylogenetic analysis clustered CCST-517 to the clade of HEV genotype 3a, together with the Japanese human HEV isolate (HE-JA10) and United States human HEV isolate (HEV-US2). Similarity plot analysis indicated that the fragment extending from 4500 to 5500 nt included evidence of one intra-genotype recombination event in the genome sequence of the CCST-517 strain. To our knowledge, this is the first report of HEV genotype 3a with its complete genome sequence revealed in China. Our findings revealed a close phylogenetic relationship of CCST-517 to human HEV-US2 and HE-JA10, implying cross-species transmission of HEV between pigs and humans.

Increased Hepatitis E Virus Seroprevalence Correlates with Lower CD4+ Cell Counts in HIV-Infected Persons in Argentina

Hepatitis E virus (HEV) is a single-stranded RNA virus that can cause hepatitis in an epidemic fashion. HEV usually causes asymptomatic or limited acute infections in immunocompetent individuals, whereas in immunosuppressed individuals such as transplant recipients, HEV can cause chronic infections. The risks and outcomes of HEV co-infection in patients infected with human immunodeficiency virus (HIV) are poorly characterized. We used a third generation immunoassay to measure serum IgG antibodies specific for HEV in 204 HIV-infected individuals from Argentina and a control group of 433 HIV-negative individuals. We found 15 of 204 (7.3%, 95%CI 3.74-10.96%) individuals in the HIV-positive group to have positive HEV IgG levels suggestive of previous infection, compared to 19 of 433 (4.4%, 95% CI 2.5-6.3%) individuals in the HIV-negative control group (p = 0.12). Among HIV-positive individuals, those with HEV seropositivity had lower CD4 counts compared to those that were HEV seronegative (average CD4 count of 234 vs 422 mm3, p = 0.01), indicating that patients with lower CD4 counts were more likely to be HEV IgG positive. Moreover, HEV seropositivity in patients with CD4 counts <200 mm3 was 16%, compared to 4.5% in those with CD4 counts >200 mm3 (p = 0.012). We found a positive PCR result for HEV in one individual. Our study found that increased seroprevalence of HEV IgG correlated with lower CD4 counts in HIV-infected patients in Argentina.