Acute viral hepatitis – Should the current screening strategy be modified?

Highlights of the drug-induced liver injury literature for 2021

INTRODUCTION

In 2021, over 3,000 articles on Drug-Induced Liver Injury (DILI) were published, nearly doubling the annual number compared to 2011. This review selected DILI articles from 2021 we felt held the greatest interest and clinical relevance.

AREAS COVERED

A literature search was conducted using PubMed between 1 March 2021 and 28 February 2022. 86 articles were included. This review discusses new and established cases of hepatotoxins, including new FDA approvals and COVID-19 therapeutics. Developments in biomarkers and causality assessment methods are discussed. Updates from registries are also explored.

EXPERT OPINION

DILI diagnosis and prognostication remain challenging. Roussel Uclaf Causality Assessment Method (RUCAM) is the best option for determining causality and has been increasingly accepted by clinicians. Revised Electronic Causality Assessment Method (RECAM) may be more user-friendly and accurate but requires further validation. Quantitative systems pharmacology methods, such as DILIsym, are increasingly used to predict hepatotoxicity. Oncotherapeutic agents represent many newly approved and described causes of DILI. Such hepatotoxicity is deemed acceptable relative to the benefit these drugs offer. Drugs developed for non-life-threatening disorders may not show a favorable benefit-to-risk ratio and will be more difficult to approve. As the COVID-19 landscape evolves, its effect on DILI deserves further investigation.

Hepatitis E virus infection among patients with altered levels of alanine aminotransferase

Hepatitis E virus (HEV) affects 20 million people worldwide, with 3.3 million cases and 56,000 deaths. The transmission is mainly by the fecal-oral route. Several studies have reported increased alanine aminotransferase (ALT) levels in association with viral hepatitis. This study evaluated the diagnosis of HEV infection among patients attending the emergency room (ER) of Hospital Beneficência Portuguesa (HBP) and Hospital São Paulo (HSP) in São Paulo, Brazil increased ALT levels (≥ 200 IU/L). From October 2018 to July 2019, 400 sera samples were collected from patients treated at the ER of HBP (n=200) and HSP (n=200). All samples were screened for HEV by RT-qPCR. 200 samples from HSP were tested for IgM of anti-Hepatitis A (HAV) and B (HBV) viruses, and total antibodies of Hepatitis C virus (HCV). Ninety samples (45 from each hospital), were tested for anti-HEV IgM antibodies. Patients aged under 1 to 91 years (mean = 46.29 ± 24.17, median = 48). ALT levels varied from 200 to 8,974 IU/l. 16 patients (4%) turned out positive for HEV by RT-qPCR (ALT levels = 299 to 698 IU/L). Of the 200 HSP patients, 18 (9%) were anti-HAV IgM reactive, 9 (4.5%) for anti-HBV IgM, and 7 (3.5%) for anti-HCV antibodies (ALT levels = 833 to 1918 IU/L). Two of 90 BPH patients (2.22%) were anti-HEV IgM reactive (ALT levels = 1502 to 3831 IU/L). This is the first Brazilian study evaluating patients with suspected HEV infection with increased ALT levels, which were higher than 12 and 60 times the normal upper limit, in the acute phase or for patients reactive for antibody detection, respectively. Liver damage could be minimized by implementing molecular diagnostic tests in the hospital routine.

The Unmet Needs of Hepatitis E Virus Diagnosis in Suspected Drug-Induced Liver Injury in Limited Resource Setting

Background: Currently, there are no specific biomarkers for drug-induced liver injury (DILI), and the diagnosis of DILI is based mainly on the exclusion of other causes of liver dysfunction and the recognition of potential causative drugs. Hepatitis E virus (HEV) diagnosis is not routinely enrolled in many countries, and HEV infection could be misdiagnosed as DILI.

Methodology: We retrospectively analyzed plasma samples (n = 80) collected from suspected DILI for HEV markers such as anti-HEV IgM, anti-HEV IgG, and HEV RNA. Anti-HEV antibodies were assessed using commercial ELISA kits. HEV RNA was tested by RT-qPCR targeting HEV ORF2/3, the receiver operating characteristic (ROC) curve was plotted, and a putative threshold for liver function parameters was determined.

Results: Out of 80 samples, 12 samples were positive for anti-HEV IgM and anti-HEV IgG, and HEV RNA was detected in seven samples. The median viral load was 3.46 × 10³ IU/ml, and the isolated viruses belonged to HEV genotype 1. The level of liver enzymes such as alanine transaminase (ALT) and aspartate transaminase (AST), but not alkaline phosphatase (ALP), was significantly higher in HEV confirmed cases than in non-HEV confirmed cases. We identified a plasma ALT level of at least 415.5 U/L and AST level of at least 332 U/L; ALT/ALP ratio of at least 5.08 could be used as a guide for the patients diagnosed as DILI to be tested for HEV infection. The previous liver function parameters showed high sensitivity and good specificity.

Conclusion: Hepatitis E virus was detected in suspected DILI cases. The diagnosis of DILI is not secure until HEV testing is done. Liver function parameters can be used as a guide for HEV testing in suspected DILI cases in countries with limited resources.

Systematic Review of Hepatitis E Virus in Brazil: A One-Health Approach of the Human-Animal-Environment Triad

Simple Summary

Hepatitis E virus (HEV) is an important causative agent of acute and chronic hepatitis worldwide. Originally identified in epidemics associated with flooding in Asia, it nowadays shows very distinct genetic and epidemiological patterns. While HEV genotypes (HEV-) 1 and 2 are associated with the original outbreaks (waterborne diseases), HEV-3 and HEV-4 present a zoonotic pattern (associated with consumption of meat from infected animals), HEV-5 and 6 have been found only in wild boar in Japan, and HEV-7 and 8 have been detected in camels and dromedary seldom affecting humans. Brazil, with a precarious sanitary structure and being an important world meat producer, was the focus of this study in order to identify patterns of occurrence of HEV. After reviewing scientific studies, it was identified that the only genotype found in Brazil is HEV-3 and the area where there were more reports was the South region of the country. This is the region that produces more pork. These results indicate that HEV-3 is widespread in the country and sanitary surveillance is essential in the national production of pigs, as well as the implementation of monitoring protocols in hospitals.

Abstract

Brazil is the fifth largest country in the world with diverse socioeconomic and sanitary conditions, also being the fourth largest pig producer in the world. The aim of the present systematic review was to collect and summarize all HEV published data from Brazil (from 1995 to October 2020) performed in humans, animals, and the environment, in a One Health perspective. A total of 2173 papers were retrieved from five search databases (LILACs, Mendeley, PubMed, Scopus, and Web of Science) resulting in 71 eligible papers after application of exclusion/inclusion criteria. Data shows that HEV genotype 3 (HEV-3) was the only retrieved genotype in humans, animals, and environment in Brazil. The South region showed the highest human seroprevalence and also the highest pig density and industry, suggesting a zoonotic link. HEV-1 and 2 were not detected in Brazil, despite the low sanitary conditions of some regions. From the present review we infer that HEV epidemiology in Brazil is similar to that of industrialized countries (only HEV-3, swine reservoirs, no waterborne transmission, no association with low sanitary conditions). Hence, we alert for the implementation of HEV surveillance systems in swine and for the consideration of HEV in the diagnostic routine of acute and chronic hepatitis in humans.

Etiologies and Features of Acute Viral Hepatitis in Spain

BACKGROUND AND AIM

Etiologies of acute viral hepatitis in high-income countries change with migration of populations, lifestyle changes, and emergence of new pathogens. We analyzed etiologies, characteristics, and outcomes of patients with acute viral hepatitis at a tertiary hospital in Spain.

METHODS

We analyzed data from all patients with acute hepatitis (n = 100; 71% male; median age, 42 years; 72% Spanish nationals), older than 16 years, diagnosed in the emergency department of an academic hospital in Barcelona, Spain, from January 2014 through December 2018. Blood samples were collected and patients with serum levels of alanine aminotransferase more than 10-fold the upper limit of normal and markers viral infection were considered to have acute viral hepatitis. We collected clinical information from patients, and samples were analyzed for IgM antibody to hepatitis B (HB) core antigen, HB surface antigen, antibody against hepatitis C virus (HCV), HCV RNA, IgM against hepatitis E virus (HEV), HEV RNA, and IgM against hepatitis A virus (HAV). Patients were followed until resolution of infections or evidence of chronic infection.

RESULTS

The most common etiologies of acute hepatitis were HBV infection (28%), HEV infection (18%), HCV infection (17%), and HAV infection (14%). The main risk factors of the cohort were sexual risk contact and intravenous drug use; 79% of cases of HAV had sexual risk behavior. Twenty-nine percent of patients with acute HAV infection and 29% of patients with HBV infection were immigrants to Spain. Fifty-four patients were hospitalized; jaundice and HCV infection were associated with hospital admission. Three patients died (2 from acute liver failure related to acute HBV infection or HBV and HDV co-infection). Chronic infections developed in 5/28 patients (18%) with acute HBV infection and 7/17 patients (41%) with acute HCV infection.

CONCLUSIONS

Despite universal vaccination against HBV in Spain, HBV remains the most frequent cause of acute viral hepatitis in our emergency department. Almost one-third of cases of acute HBV and HAV infections were immigrants, possibly from countries with suboptimal vaccination programs. A high proportion of patients with acute hepatitis have HEV infection (18%); acute HAV infection was associated with sexual risk behavior.

Development of machine learning model for diagnostic disease prediction based on laboratory tests

The use of deep learning and machine learning (ML) in medical science is increasing, particularly in the visual, audio, and language data fields. We aimed to build a new optimized ensemble model by blending a DNN (deep neural network) model with two ML models for disease prediction using laboratory test results. 86 attributes (laboratory tests) were selected from datasets based on value counts, clinical importance-related features, and missing values. We collected sample datasets on 5145 cases, including 326,686 laboratory test results. We investigated a total of 39 specific diseases based on the International Classification of Diseases, 10th revision (ICD-10) codes. These datasets were used to construct light gradient boosting machine (LightGBM) and extreme gradient boosting (XGBoost) ML models and a DNN model using TensorFlow. The optimized ensemble model achieved an F1-score of 81% and prediction accuracy of 92% for the five most common diseases. The deep learning and ML models showed differences in predictive power and disease classification patterns. We used a confusion matrix and analyzed feature importance using the SHAP value method. Our new ML model achieved high efficiency of disease prediction through classification of diseases. This study will be useful in the prediction and diagnosis of diseases.

Kynurenic Acid Protects against Thioacetamide-Induced Liver Injury in Rats

Acute liver failure (ALF) is a life-threatening disorder of liver function. Kynurenic acid (KYNA), a tryptophan metabolite formed along the kynurenine metabolic pathway, possesses anti-inflammatory and antioxidant properties. Its presence in food and its potential role in the digestive system was recently reported. The aim of this study was to define the effect of KYNA on liver failure. The Wistar rat model of thioacetamide-induced liver injury was used. Morphological and biochemical analyses as well as the measurement of KYNA content in liver and hepatoprotective herbal remedies were conducted. The significant attenuation of morphological disturbances and aspartate and alanine transaminase activities, decrease of myeloperoxidase and tumor necrosis factor-α, and elevation of interleukin-10 levels indicating the protective effect of KYNA in thioacetamide (TAA) - induced liver injury were discovered. In conclusion, the hepatoprotective role of KYNA in an animal model of liver failure was documented and the use of KYNA in the treatment of ALF was suggested.

Changes in acute viral hepatitis epidemiology in the Turkish adult population: A multicenter study

BACKGROUND/AIMS

The present study aimed to determine the changes in the epidemiology of hepatitis in recent years in an adult Turkish population.

MATERIALS AND METHODS

Overall, 852 patients with acute viral hepatitis from 17 centers were included in this study. Their sociodemographic characteristics, clinical courses, treatments, and laboratory findings were retrospectively analyzed.

RESULTS

The most commonly found microorganisms were the hepatitis B virus (55.2%) and hepatitis A virus (37.6%), and the types of acute viral hepatitis differed significantly according to the age group (p≤0.001). The most frequently reported symptom was fatigue (73.7%), and the most common complications were cholecystitis (0.4%) and fulminant hepatitis (0.4%). The median hospital stay was 9 days (range 1-373). In total, 40.8% patients with acute hepatitis B virus developed immunity.

CONCLUSION

In Turkey, there are significantly large adolescent and adult populations susceptible to acute viral hepatitis. Therefore, larger vaccination programs covering these age groups should be implemented.

Hepatitis E virus - key points for the clinical haematologist

In recent years there has been a paradigm shift in our understanding of the epidemiology and clinical features of hepatitis E virus (HEV) infection. Once classically described as an acute hepatitis associated with waterborne outbreaks in areas of poor sanitation, HEV is now recognised to be endemic in Europe and is probably zoonotic in origin. Evidence for transfusion-transmitted HEV has prompted the introduction of blood donor screening in a number of countries, but the risk to the haematology patient from food sources remains. The aim of this review therefore, is to equip the clinical haematologist with the knowledge required to diagnose HEV infection and to aid decision-making in patient management. The article also provides information on addressing patient concerns about their risk of acquiring hepatitis E and how this risk can be mitigated.

The added value of hepatitis E diagnostics in determining causes of hepatitis in routine diagnostic settings in the Netherlands

OBJECTIVES

Hepatitis E virus (HEV) genotype 3 is endemic in Europe and an underdiagnosed and emerging (public) health issue. In recent years commercial enzyme immunoassays (EIAs) that detect antibodies to HEV more adequately, became available. We investigated the added value of this HEV serology in the diagnostic work flow to detect viral causes of recent hepatitis.

METHODS

During a 2-year period (May 2013 to May 2015), HEV serology was added to the hepatitis work flow, consisting of serological detection of hepatitis viruses A, B and C (HAV, HBV, HCV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Samples positive for HEV IgM were also analysed using PCR to detect HEV RNA. If positive, HEV sequencing was performed for genotyping purposes.

RESULTS

In 235 out of 2521 patients (9.3%), a viral cause for hepatitis was found. Recent HAV, HBV, HCV, EBV or CMV infections were serologically diagnosed in 3, 34, 10, 69 and 42 patients, respectively. Seventy-eight patients (3.1%) had a recent HEV infection. In 49 of them, sufficient HEV RNA was present for genotyping. All patients were infected with HEV genotype 3.

CONCLUSIONS

In our region, an HEV infection is the most frequently diagnosed viral cause for recent hepatitis. These results indicate that, in a country where HEV is endemic, serological HEV diagnostics should be added to the standard work-up for viral hepatitis.

Investigation of liver dysfunction: who should we test for hepatitis E?

AIM

Hepatitis E virus (HEV) is endemic in developed countries, but unrecognized infection is common. Many national guidelines now recommend HEV testing in patients with acute hepatitis irrespective of travel history. The biochemical definition of 'hepatitis' that best predicts HEV infection has not been established. This study aimed to determine parameters of liver biochemistry that should prompt testing for acute HEV.

METHODS

This was a retrospective study of serial liver function tests (LFTs) in cases of acute HEV (n=74) and three comparator groups: common bile duct stones (CBD, n=87), drug-induced liver injury (DILI, n=69) and patients testing negative for HEV (n=530). To identify the most discriminating parameters, LFTs from HEV cases, CBD and DILI were compared. Optimal LFT cutoffs for HEV testing were determined from HEV true positives and HEV true negatives using receiver operating characteristic curve analysis.

RESULTS

Compared with CBD and DILI, HEV cases had a significantly higher maximum alanine aminotransferase (ALT) (P<0.001) and ALT/alkaline phosphatase (ALKP) ratio (P<0.001). For HEV cases/patients testing negative for HEV, area under receiver operating characteristic curve was 0.805 for ALT (P<0.001) and 0.749 for the ALT/ALKP ratio (P<0.001). Using an ALT of at least 300 IU/l to prompt HEV testing has a sensitivity of 98.6% and a specificity of 30.3% compared with an ALT/ALKP ratio higher than or equal to 2 (sensitivity 100%, specificity 9.4%).

CONCLUSION

Patients with ALT higher than or equal to 300 IU/l should be tested for HEV. This is simple, detects nearly all cases and requires fewer samples to be tested than an ALT/ALKP ratio higher than or equal to 2. Where clinically indicated, patients with an ALT less than 300 IU/l should also be tested, particularly if HEV-associated neurological injury is suspected.

First Directly Sequenced Genome of Hepatitis E Virus from the Serum of a Patient from the United Kingdom

Hepatitis E virus (HEV) genotype 3 is endemic in the United Kingdom but the complete sequence of HEV, generated directly from a clinical sample, is lacking. We report a near full-length genome sequence of genotype 3 HEV from the serum of a patient with acute hepatitis.

Hepatitis E virus as a Cause of Acute Hepatitis in The Netherlands

BACKGROUND

Recent studies indicate that 27% of Dutch blood donors have evidence of past infection with HEV. However, the low number of diagnosed HEV infections indicates either an asymptomatic course or under diagnosis.

OBJECTIVES

We investigated whether HEV is a cause of acute hepatitis in Dutch patients and which diagnostic modality (serology or PCR) should be used for optimal detection.

STUDY DESIGN

Serum samples were retrospectively selected from non-severely immuno-compromised patients from a university hospital population, suspected of having an infectious hepatitis. Criteria were: elevated alanine aminotransferase (ALT> 34 U/l) and request for antibody testing for CMV, EBV or Hepatitis A (HAV).

RESULTS

All samples were tested for HEV using ELISA and PCR. Ninety patients/sera were tested, of which 22% were HEV IgG positive. Only one serum was IgM positive. HEV PCR was positive in two patients: one patient was both HEV IgM and IgG positive, the other patient was only IgG positive. Both HEV RNA positive samples belonged to genotype 3. Evidence of recent infection with CMV, EBV and HAV was found in 13%, 10% and 3% respectively.

CONCLUSIONS

Although our study is limited by small numbers, we conclude that HEV is a cause of acute hepatitis in hospital associated patients in The Netherlands. Moreover, in our study population the prevalence of acute HAV (3%) was almost similar to acute HEV (2%). We propose to incorporate HEV testing in panels for acute infectious hepatitis. Negative results obtained for HEV IgM in a HEV PCR positive patient, indicates that antibody testing alone may not be sufficient and argues for PCR as a primary diagnostic tool in hospital associated patients. The high percentage of HEV IgG seropositivity confirms earlier epidemiological studies.

Assessment of a Flavone-Polysaccharide Based Prescription for Treating Duck Virus Hepatitis

Because polysaccharide and flavone ingredients display good antiviral activity, we developed a flavone/polysaccharide-containing prescription that would be effective against duck viral hepatitis (DVH) and investigated its hepatoprotective effects. Flavones were derived from Hypericum japonicum (HJF) (entire herb of Hypericum japonicum Thunb) and Salvia plebeia (SPF) (entire herb of Salvia plebeia R. Br.), and polysaccharides were derived from Radix Rehmanniae Recens (RRRP) (dried root of Rehmannia glutinosa Libosch). This prescription combination was based on the theory of syndrome differentiation and treatment in traditional Chinese veterinary medicine. In vitro and in vivo experiments were conducted using the three single ingredients compared to the combined HRS prescription to determine their anti-duck hepatitis A viral (anti-DHAV) activity. The results showed that all experimental conditions displayed anti-DHAV activity, but the HRS prescription presented the best effect. To further investigate the hepatoprotective effect of the HRS prescription on DHAV-induced hepatic injury, we tested the mortality rate, the hepatic pathological severity score, plasma biochemical indexes of hepatic function, blood DHAV gene expression levels and peroxidation damage evaluation indexes and then analyzed correlations among these indexes. The results demonstrated that the HRS prescription significantly decreased the mortality rate, reduced the severity of hepatic injury, decreased the hepatic pathological severity score, depressed blood DHAV gene expression levels, and returned the indexes of hepatic function and peroxidation almost to a normal level. These results indicate that the HRS prescription confers an outstanding hepatoprotective effect, and we expect that it will be developed into a new candidate anti-DHAV drug.

Hepatitis E virus is the leading cause of acute viral hepatitis in Lothian, Scotland

Acute viral hepatitis affects all ages worldwide. Hepatitis E virus (HEV) is increasingly recognized as a major cause of acute hepatitis in Europe. Because knowledge of its characteristics is limited, we conducted a retrospective study to outline demographic and clinical features of acute HEV in comparison to hepatitis A, B and C in Lothian over 28 months (January 2012 to April 2014). A total of 3204 blood samples from patients with suspected acute hepatitis were screened for hepatitis A, B and C virus; 913 of these samples were also screened for HEV. Demographic and clinical information on patients with positive samples was gathered from electronic patient records. Confirmed HEV samples were genotyped. Of 82 patients with confirmed viral hepatitis, 48 (59%) had acute HEV. These patients were older than those infected by hepatitis A, B or C viruses, were more often male and typically presented with jaundice, nausea, vomiting and/or malaise. Most HEV cases (70%) had eaten pork or game meat in the few months before infection, and 14 HEV patients (29%) had a recent history of foreign travel. The majority of samples were HEV genotype 3 (27/30, 90%); three were genotype 1. Acute HEV infection is currently the predominant cause of acute viral hepatitis in Lothian and presents clinically in older men. Most of these infections are autochthonous, and further studies confirming the sources of infection (i.e. food or blood transfusion) are required.

Hepatitis E virus infection: an emerging occupational risk?

BACKGROUND

Hepatitis E virus (HEV) infection is endemic in many developing countries, causing substantial morbidity. Transmission is primarily faeco-oral and is associated with both sporadic infections and epidemics in areas where poor sanitation and weak public health infrastructures exist. Recently, it has become clear that HEV is also an endemic disease in industrialized countries. Moreover, a porcine reservoir and growing evidence of zoonotic transmission have been reported in these countries, suggesting the possibility of occupational transmission to man.

AIMS

To summarize the current knowledge on the epidemiology and prevention of transmission of HEV infection in occupational settings.

METHODS

The following key words were used to explore PubMed: hepatitis E, disease, epidemiology, profession(al), occupation(al).

RESULTS

After screening of the results, 107 publications were retained. In non-endemic regions, seroprevalence varied from a few per cent (2-7.8%) in Europe, Japan and South America to 18.2-20.6% in the USA, Russia, UK, southern France and Asia. A meta-analysis of 12 cross-sectional studies evaluating HEV immunoglobulin G (IgG) seroprevalence in individuals occupationally exposed to swine showed greater odds of seropositivity in the exposed group but also a high degree of heterogeneity. A funnel plot suggested publication bias.

CONCLUSIONS

There was a significant association between occupational exposure to swine and HEV IgG seroprevalence, but the level of prevalence detected depended also on the type of HEV IgG kits used. Further research, including on mechanisms and risk factors for infection, as well as the development of better serological tests for identification of infection, is required.

Hepatitis E in developed countries: current status and future perspectives

Hepatitis E virus (HEV) was for many years thought to be found almost exclusively in developing countries, where it is a major health issue. Recent studies have shown that HEV causes acute and chronic infection in developed countries. In these geographical settings, HEV is primarily a porcine zoonosis caused by genotypes 3 (HEV3) and 4 (HEV4). The clinical phenotype of hepatitis E continues to emerge, and recent data show that HEV is associated with a range of neurological syndromes including Guillain-Barré syndrome and neuralgic amytrophy.

Detection of Hepatitis E Virus Antibodies in Dogs in the United Kingdom

Hepatitis E virus (HEV) genotypes 3 and 4 are zoonotic pathogens, with pigs predominantly implicated in disease transmission. The rapid rise in human cases in developed countries over the past decade indicates a change in epidemiology of HEV, and it has been suggested that additional animal species may be involved in transmission of infection. Multiple studies have identified contact with dogs as a risk factor for HEV infection in industrialised nations, and a low seroprevalence to HEV has previously been reported in dogs in low-income countries. In this study we aimed to evaluate the possibility that dogs are susceptible to HEV, and determine the frequency with which this occurs. Serum samples from UK dogs with and without hepatitis were screened for HEV-specific antibodies, and canine liver and stool samples were analysed by qPCR for the presence of HEV RNA. We describe evidence to show HEV infection occurs at low levels in dogs in the UK, but the strain of origin is undetermined. The low seroprevalence level of HEV in dogs implies the risk of zoonotic disease transmission is likely to be limited, but further investigations will be required to determine if HEV-infected dogs can transmit HEV to man.

Hepatitis E virus: do locally acquired infections in Australia necessitate laboratory testing in acute hepatitis patients with no overseas travel history?

Hepatitis E virus (HEV) is emerging as a global public health threat. Water-borne HEV outbreaks are common in developing countries and are associated with genotypes 1 and 2. In industrialised countries, sporadic cases of zoonotic transmission associated with genotypes 3 and 4 are increasingly being reported. Transfusion- and transplantation-transmitted HEV have been documented, although ingestion of contaminated food is thought to be the major transmission route. Severe disease is possible and chronic hepatitis infection occurs in solid-organ-transplant recipients and in patients with immunosuppressive disorders. In Australia, HEV cases are mainly travellers returning from disease endemic countries. Indeed, there are few reported cases of locally acquired HEV. Pigs in Australia have been shown to be infected with HEV, which indicates the possibility of zoonotic transmission. The extent of locally acquired infection is not known, however it may be greater than expected and may necessitate laboratory testing in patients reporting no overseas travel.

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

BACKGROUND

The hepatitis E virus (HEV) is an emergent causative agent of acute hepatitis worldwide, transmitted by fecal-oral route. In Argentina it is considered rare, so differential laboratory testing is not routinely performed. Besides, in Argentina's central area epidemiological and molecular characteristics of HEV are still unknown.

OBJECTIVES

Provide evidence of local circulation of HEV by molecular detection on environmental samples and by serological survey in healthy adult population of Córdoba city, Argentina.

STUDY DESIGN

Environmental surveillance was conducted in river and sewage samples collected between 2007 and 2009-2011. Viral detection was performed by RT-Nested PCR of ORF-1 and ORF-2 partial regions. Anti-HEV IgG was determined by EIA in 433 serum samples collected between 2009 and 2010.

RESULTS

HEV was detected in 6.3% of raw sewage samples and in 3.2% of riverine samples. Nucleotide sequencing analyses revealed that all isolates belonged to genotype 3, subtypes a, b and c. The prevalence of IgG anti-HEV was 4.4%. Seroprevalence increased with the age of the individuals (OR: 3.50; 95% CI 1.39-8.87; p=0.0065) and, although the prevalence was higher in low income population, no statistical relation was found between anti-HEV and socioeconomic level.

CONCLUSIONS

The environmental findings added to serological results, demonstrate that HEV circulates in central Argentina. Contamination of water with HEV could represent a route of transmission for local populations, which have a high number of susceptible individuals. This fact alerts local health care systems in order to include detection of HEV in the diagnostic algorithm of viral hepatitis.