Acute sporadic hepatitis E in Sudanese children: analysis based on a new western blot assay

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fulminant hepatitis E in an infant

Hepatitis E virus (HEV) is an enterically transmitted infection that is typically self-limited. It spreads by fecally contaminated water within endemic areas. Hepatitis E infection occurs in both sporadic and epidemic forms in developing countries. HEV infection is usually subclinical in children but in a pregnant woman, it manifests commonly as fulminant hepatic failure. A few cases of acute liver failure caused primarily by HEV infection in children have been reported. We present a case of fulminant hepatitis E in a 1-year-old child. She showed positive signs of hepatic encephalopathy, jaundice, and coagulopathy and was given symptomatic treatment for the same. She recovered due to the self-limiting nature of HEV infection and prompt symptomatic relief.

A Single Lineage of Hepatitis E Virus Causes Both Outbreaks and Sporadic Hepatitis in Sudan

Few studies have reported sporadic hepatitis E virus (HEV) infections during non-outbreak periods in Africa. In this study, the prevalence of HEV infection in Sudan was investigated in 432 patients with acute hepatitis from 12 localities in North Kordofan, and from 152 patients involved in smaller outbreaks of hepatitis in the neighbouring Darfur. HEV infection was diagnosed in 147 (25%) patients: 98 from Kordofan and 49 from Darfur. The mortality was 10%; six of the patients who died from the infection were pregnant women. HEV RNA was detected by quantitative real-time polymerase chain reaction (RT-qPCR) in 38 (26%) patients: 22 from Kordofan and 16 from Darfur. Partial open reading frame (ORF) 1 and ORF2 were sequenced from HEV from nine and three patients, respectively. Phylogenetic analysis showed that the Sudanese strains belonged to genotype 1 (HEV1), and confirmed the segregation of African HEV1 strains into one branch divergent from Asian HEV1. It also revealed that the Sudanese strains from this study and from an outbreak in 2004 formed a separate clade with a common ancestor, distinct from strains from the neighbouring Chad and Egypt. This HEV strain has thus spread in a large area of Sudan, where it has caused both sporadic hepatitis E and outbreaks from at least 2004 and onwards. These data demonstrate that hepatitis E is a constant, on-going public health problem in Sudan and that there is a need for hepatitis E surveillance, outbreak preparedness, and general improvements of the sanitation in these remote areas of the country.

Dengue and hepatitis E virus infection in pregnant women in Eastern Sudan, a challenge for diagnosis in an endemic area

Dengue fever and hepatitis E virus infection are both a public health problem in developing countries due to poor sanitation. Infection with viral hepatitis and dengue fever can present with similar clinical such and fever, headache and abortion. This study was conducted in Port-Sudan city in the eastern part of the country. ELISA and Real Time PCR tests were used to detect the infection. A total number of 39 pregnant women with a mean age 26 ±7.8 were included in the study. All of them had fever, 32 (92.3%) admitted with headache, 11 (28.2%) of them had vomiting, and abortion was reported in two cases (5.1%). The study showed that 4 (10.3%) of pregnant women were positive for the Hepatitis E virus, 5 (12.8%) positive for Dengue virus IgG, and only one sample (2.6%) was positive for IgM capture ELISA and real time PCR. Death due to hepatitis E infection was reported in one case with 7^th month of pregnancy. Most of hepatitis cases were reported in the central sector of the Portsudan city. The diagnosis of hepatitis E virus and dengue virus in an endemic area is a great challenge for health care staff working in these areas. Both Dengue virus and Hepatitis E virus infection should be considered in pregnant women especially in similar settings.

A systematic review of the epidemiology of hepatitis E virus in Africa

BACKGROUND

Hepatitis E Virus (HEV) infection is a newly recognized serious threat to global public health and Africa is suspected to be among the most severely affected regions in the world. Understanding HEV epidemiology in Africa will expedite the implementation of evidence-based control policies aimed at preventing the spread of HEV including policies for the use of available resources such as HEV vaccines.

METHODS

Here we present a comprehensive review of HEV epidemiology in Africa based on published data. We searched for articles on HEV epidemiology in Africa from online databases such as PubMed, Scopus, and ISI Web of Science and critically reviewed appropriate publications to extract consistent findings, identify knowledge gaps, and suggest future studies.

RESULTS

Taking a particularly high toll in pregnant women and their fetuses, HEV has infected human populations in 28 of 56 African countries. Since 1979, 17 HEV outbreaks have been reported about once every other year from Africa causing a reported 35,300 cases with 650 deaths.

CONCLUSIONS

In Africa, HEV infection is not new, is widespread, and the number of reported outbreaks are likely a significant underestimate. The authors suggest that this is a continent-wide public health problem that deserves the attention of local, regional and international agencies to implement control policies that can save numerous lives, especially those of pregnant women and their fetuses.

Seroprevalence of hepatitis e virus among primary school children

Objectives: To investigate the seroprevalence of anti-hepatitis E virus antibody among primary school children in the two different areas of Denizli, Turkey.

Methodology: Anti-HEV antibodies were investigated in 185 primary school children (91 from rural areas and 94 from urban areas of Denizli). The children were divided into two age groups as seven-year old group and fourteen-year old group. Samples were tested for anti-HEV Ab by an enzyme-linked immunoassay.

Results: A total of 23 primary school children were anti-HEV Ab positive, giving a prevalence of 12.4%. The seroprevalence rate was 13.1% in rural areas and 11.7% in urban areas. The difference in the seropositive rates was not statistically significant (p>0.05). Among 185 primary school children, Anti-HEV antibodies were positive 17 (18.1%) in seven-year old group, and 6 (6.6%) in fourteen-year old group. The difference in the seropositive rates was statistically significant (p<0.05).

Conclusions: There was no association between the anti-HEV Ab and gender, socioeconomic level, parental educational level, rural or urban areas. Anti-HEV Ab seroprevalence was higher in seven-year old children than fourteen-year old children.

Hepatitis E in three immunocompromized children in southeastern France

Hepatitis E virus (HEV) causes an emerging autochthonous disease in developed countries where links with a viral porcine reservoir have been evidenced. Moreover, chronic HEV infection and associated-cirrhosis have been described in severely immunocompromized patients. Nonetheless, only few studies have focused on pediatric HEV infections worldwide and only four autochthonous cases have been reported in children in developed countries. We describe here acute hepatitis E in three immunocompromized children. Case no. 1 was a 9-year-old liver transplant recipient girl in whom H1N1 2009 flu infection was diagnosed concurrently with hepatitis E. Case no. 2 was a 12-year-old boy presenting early medullar relapse of lymphoblastic leukemia of type B and in whom HEV RNA was detected over a 29-week period. Case no. 3 was a 9-year-old boy with a rare primary immunodeficiency due to XIAP deficiency. HEV infections were all autochthonously acquired and involved different viruses classified as subtype f, c, and e of genotype 3, which are those described in autochthonous cases in Europe. These three observations prompt to consider HEV as a causative agent of hepatitis in children in developed countries, and to perform particularly HEV testing in those severely immunocompromized who may develop chronic hepatitis E.

Hepatitis E: an emerging infection in developed countries

Hepatitis E is endemic in many developing countries where it causes substantial morbidity. In industrialised countries, it is considered rare, and largely confined to travellers returning from endemic areas. However, there is now a growing body of evidence that challenges this notion. Autochthonous hepatitis E in developed countries is far more common than previously recognised, and might be more common than hepatitis A. Hepatitis E has a predilection for older men in whom it causes substantial morbidity and mortality. The disease has a poor prognosis in the context of pre-existing chronic liver disease, and is frequently misdiagnosed as drug-induced liver injury. The source and route of infection remain uncertain, but it might be a porcine zoonosis. Patients with unexplained hepatitis should be tested for hepatitis E, whatever their age or travel history.

Epidemiology of viral hepatitis in Sudan

Hepatitis virus infections are the most common cause of liver disease worldwide. Sudan is classified among the countries with high hepatitis B virus seroprevalence. Exposure to the virus varied from 47%–78%, with a hepatitis B surface antigen prevalence ranging from 6.8% in central Sudan to 26% in southern Sudan. Studies pointed to infection in early childhood in southern Sudan while there was a trend of increasing infection rate with increasing age in northern Sudan. Hepatitis B virus was the commonest cause of chronic liver disease and hepatocellular carcinoma and was the second commonest cause of acute liver failure in the Sudan. Studies of hepatitis C virus showed a low seroprevalence of 2.2%–4.8% and there was no association with schistosomiasis or with parenteral antischistosomal therapy. Hepatitis E virus was the commonest cause of acute hepatitis among pediatric, adult, and displaced populations. Recent introduction of screening of blood and blood products for hepatitis B virus and hepatitis C virus infections and the introduction of hepatitis B virus vaccine as part of the extended program of immunization is expected to reduce the infection rate of these viruses in the Sudan.

Seroprevalence of hepatitis E virus infection among institutionalized psychiatric patients in Taiwan

BACKGROUND

Hepatitis E virus infection (HEV) remains unclear in institutionalized psychiatric patients.

OBJECTIVES

To investigate the prevalence and risk factors of HEV infection in a psychiatric institution in Taiwan.

STUDY DESIGN

A total of 754 patients with psychiatric disorders were enrolled in the study. Clinical features, review of patient charts, and interviews with families were recorded for analysis. Antibody to HEV was tested using a commercial enzyme-linked immunosorbent assays.

RESULTS

The prevalence of HEV infection in institutionalized patients was as high as 14.5%. Males had higher prevalence than females. It was also found prevalence increased significantly by age group. When compared with patients 30 years old or less, those in the 31-40 year old age group had an odds ratio of 4.89 [95% confidence interval (CI), 1.15-20.82], 41-50 years old of 6.30 (95% CI, 1.48-26.83), and 50 years or older of 6.20 (95% CI, 1.44-26.74). In multivariate logistic regression analysis, age and male gender were the independent risk factors.

CONCLUSIONS

Institutionalized psychiatric patients had higher prevalence of HEV infection. In addition, there was an age-related increase in exposure to HEV with males that had a higher HEV seropositivity.

Does co-infection with multiple viruses adversely influence the course and outcome of sporadic acute viral hepatitis in children?

BACKGROUND

This study looked at the frequency of co-infection with multiple hepatotropic viruses and the effect of such infection on the course and outcome of acute sporadic viral hepatitis (AVH) and fulminant hepatic failure (FHF) in children.

METHODS

Consecutive children up to 15 years of age presenting with AVH or FHF between January 1998 and July 2002 were evaluated prospectively. The following viral markers were assessed in all children: immunoglobulin M (IgM) anti-hepatitis A virus (HAV), IgM anti-hepatitis E virus (HEV), hepatitis B surface antigen (HBsAg), IgM anti-hepatitis B core (HBc), and anti-hepatitis C virus (HCV).

RESULTS

A total of 149 children were included in the study, 122 with AVH and 27 with FHF. Co-infection with multiple viruses was detected in 30 (24.6%) AVH patients (A+E in 24, A+B in three, and E+B, A+C and A+E+B in one each) and seven (26%) FHF patients (A+E in five, and A+B and E+B in one each). The majority of single infections were due to HAV (AVH 70/92, FHF 14/20) followed by HEV (AVH 9/92, and FHF 5/20). HEV infection was associated with infection with another agent in 88% of patients with AVH (odds ratio 53, 95% confidence interval 15-186, P<0.0001). Frequency of anicteric state, prolonged cholestasis, relapsing hepatitis, ascites, hemolysis and mortality rates were similar in the single and multiple infection groups for both AVH and FHF patients.

CONCLUSIONS

Co-infection with multiple viruses is observed in one-quarter of patients with sporadic AVH in childhood. Such infection does not produce a more severe disease. HEV positivity is a strong marker for multiple infections.

Health risks of enteric viral infections in children

Children are at a greater risk of infections from serious enteric viral illness than adults for a number of reasons. Most important is the immune system, which is needed to control the infection processes. This difference can lead to more serious infections than in adults, who have fully developed immune systems. There are a number of significant physiological and behavioral differences between adults and children that place children at a greater risk of exposure and a greater risk of serious infection from enteric viruses. Although most enteric viruses cause mild or asymptomatic infections, they can cause a wide range of serious and life-threatening illnesses in children. The peak incidence of most enteric viral illnesses is in children <2yr of age, although all age groups of children are affected. Most of these infections are more serious and result in higher mortality in children than adults. The fetus is also affected by enterovirus and infectious hepatitis resulting in significant risk of fetal death or serious illness. In addition to the poliovirus vaccine, the only vaccine available is for hepatitis A virus (HAV). A vaccine for rotavirus has currently been withdrawn, pending review because of potential adverse effects in infants. No specific treatment is available for the other enteric viruses. Enteric viral infections are very common in childhood. Most children are infected with rotavirus during the first 2yr of life. The incidence of enteroviruses and the viral enteric viruses ranges from 10% to 40% in children and is largely dependent on age. On average, half or more of the infections are asymptomatic. The incidence of hepatitis A virus is much lower than the enteric diarrheal viruses. There is no current evidence for hepatitis E virus (HEV) acquisition in children in the U.S. Enteric viral diseases have a major impact on direct and indirect health care costs (i.e., lost wages) and amount to several billion dollars a year in the U.S. Total direct and indirect costs for nonhospitalized cases may run from $88/case for Norwalk virus to $1,193/case for enterovirus aseptic meningitis. Direct costs of hospitalization ran from $887/case for Norwalk virus to $86,899/case for hepatitis A. These costs are based on 1997-1999 data. Generally, attack rates during drinking water outbreaks are greater for children than adults. The exception appears to be hepatitis E virus where young adults are more affected. However, pregnant women suffer a high mortality, resulting in concurrent fetal death. Also, secondary attack rates are much higher among children, probably because of fewer sanitary habits among this age group. Overall, waterborne outbreaks of viral disease have a greater impact among children than adults. To better quantify the impact on children, the literature hould be further reviewed for case studies of waterborne outbreaks where data are available on the resulting illness by age group. The EPA and/or Centers for Disease Control should attempt to collect these data as future outbreaks are documented.

HEV, TTV and GBV-C/HGV markers in patients with acute viral hepatitis

The aim of the present study was to evaluate the prevalence of HEV, TTV and GBV-C/GBV-C/HGV in patients with acute viral hepatitis A, B and non-A-C. We evaluated sera of 94 patients from a sentinel program who had acute hepatitis A (N = 40), B (N = 42) and non-A-C (N = 12); 71 blood donors served as controls. IgM and anti-HEV IgG antibodies were detected by enzyme immunoassay using commercial kits. TTV and GBV-C/HGV were detected by nested PCR; genotyping was done by sequencing and phylogenetic analysis. Anti-HEV IgG was present in 38, 10 and 17% of patients with hepatitis A, B and non-A-C. Four patients with hepatitis A and 1 with non-A-C hepatitis also had anti-HEV IgM detected in serum. TTV was detected in 21% of patients with acute hepatitis and in 31% of donors. GBV-C/HGV was detected in 9% of patients with hepatitis, and in 10% of donors. We found TTV isolates of genotypes 1, 2, 3, and 4 and GBV-C/HGV isolates of genotypes 1 and 2. Mean aminotransferase levels were lower in patients who were TTV or GBV-C/HGV positive. In conclusion, the detection of anti-HEV IgM in some acute hepatitis A cases suggests co-infection with HEV and hepatitis E could be the etiology of a few cases of sporadic non-A-C hepatitis in Salvador, Brazil. TTV genotype 1, 2, 3 and 4 isolates and GBV-C/HGV genotype 1 and 2 strains are frequent in the studied population. TTV and GBV-C/HGV infection does not appear to have a role in the etiology of acute hepatitis.

Viral diseases of the liver in children: diagnostic and differential diagnostic considerations

This review summarizes the general histologic features of acute and chronic hepatitides and highlights those morphologic findings that may suggest or be diagnostic of a specific agent or etiology. The main epidemiologic, clinical, and pathologic features of the hepatotropic viruses are discussed, with an emphasis on pediatric studies and the differential diagnosis of hepatitis in childhood.

Hepatitis E virus (HEV) capsid antigens derived from viruses of human and swine origin are equally efficient for detecting anti-HEV by enzyme immunoassay

The recombinant truncated ORF2 (capsid) antigen derived from the Meng strain of swine hepatitis E virus (HEV) differs from that of the Sar-55 strain of human HEV by approximately 5% at the amino acid level. Serial serum samples from two chimpanzees and six rhesus monkeys experimentally infected with HEV were tested with one enzyme immunoassay (EIA) based on the Sar-55 antigen and with a second EIA based on the Meng antigen. We obtained 98% agreement (kappa = 0.952) by direct comparison. The virtually identical results obtained with these antigens in detecting seroconversion following infection with HEV suggests that they were reacting with antibodies that detect the same or very similar epitopes of HEV. We then tested human and swine serum samples for anti-HEV in EIAs that utilized one or the other of the two ORF2 antigens and showed that these results were also virtually identical. The specimens tested included swine sera from the United States, Canada, China, Korea, and Thailand and sera from veterinarians, U.S. and non-U.S. volunteer blood donors, and U.S. and non-U.S. animal handlers. We tested 792 swine sera and obtained 93% agreement (kappa = 0.839). We similarly tested 882 human sera and obtained 99% agreement (kappa = 0.938). Moreover, we found virtually no difference in the levels of prevalence of anti-HEV as measured by the two tests, again suggesting that the antigens derived from human and swine HEV contain the same immunodominant epitopes.

New perspectives on hepatitis E

The infectious agent causing epidemic non-A, non-B hepatitis was identified in 1983 from a human challenge experiment. The novel hepatitis E virus (HEV) subsequently was cloned in 1990 and the genome sequenced. HEV transmission is highly endemic in Asia, the Middle East, and Africa. Fecal contamination of drinking water is the most common mode of spread. Although usually asymptomatic, HEV infection can cause fulminant hepatitis. Recent studies indicate that hepatitis E may be a zoonotic disease, with pigs and possibly rats serving as reservoirs for human infection. A recombinant HEV vaccine is currently in phase III clinical trials. The characterization of the major types of viral hepatitis during the last 20 years illustrates how modern genetic technology has revolutionized research in infectious diseases. Within less than two decades of the discovery of HEV, its epidemiology has been described, serologic tests have been developed, and a candidate vaccine has been evaluated in clinical trials.

Spread of hepatitis E virus among different-aged pigs: two-year survey in Taiwan

Swine are reservoirs of hepatitis E virus (HEV). In this study, a 2-year survey of HEV in feces and sera of swine was conducted to determine if: 1) HEV has circulated among pigs for some time in Taiwan; 2) the spread of HEV among different-aged pigs; and 3) there exists HEV strains possibly imported through trading. From 1998-2000, 521 serum samples and 54 fecal specimens from pigs were examined by reverse transcription polymerase chain reaction. None of the 11 pigs in suckling stage (< 2 months) were serum HEV RNA positive. The highest viremia rate (4.5%) was in pigs of 2 months age, followed by 1.2% and 1.8% in pigs of growing (3-4 months) and finishing stages (5-6 months), and none in pigs older than 6 months. Viremia showed little variation in different years and areas. None of the 20 fecal samples from pigs in suckling stage were HEV RNA positive, whereas 9% of the 34 samples from pigs in growing or finishing stages were positive. Most swine HEV isolates in Taiwan clustered within the genotype 4, whereas the three HEV isolates cloned from pigs imported recently from the U.S. belonged to the genotype 3 HEV in the U.S. The results suggest that HEV may infect pigs at an early growing stage and spread unnoticed among pigs and possibly across countries through trading.

A review of hepatitis E virus

Hepatitis E virus (HEV) is a major cause of outbreaks and sporadic cases of viral hepatitis in tropical and subtropical countries but is infrequent in industrialized countries. The virus is transmitted by the fecal-oral route with fecally contaminated drinking water being the usual vehicle. Hepatitis resulting from HEV infection is a moderately severe jaundice that is self-limiting in most patients. Young adults, 15 to 30 years of age, are the main targets of infection, and the overall death rate is 0.5 to 3.0%. However, the death rate during pregnancy approaches 15 to 25%. Death of the mother and fetus, abortion, premature delivery, or death of a live-born baby soon after birth are common complications of hepatitis E infection during pregnancy. Hepatitis E virus is found in both wild and domestic animals; thus, HEV is a zoonotic virus. The viruses isolated from swine in the United States or Taiwan are closely related to human HEV found in those areas. The close genetic relationship of the swine and human virus suggests that swine may be a reservoir of HEV. In areas where swine are raised, swine manure could be a source of HEV contamination of irrigation water or coastal waters with concomitant contamination of produce or shellfish. Increasing globalization of food markets by industrialized countries has the potential of introducing HEV into new areas of the world. The purpose of this review is to cover certain aspects of hepatitis E including the causative agent, the disease, diagnosis, viral detection, viral transmission, epidemiology, populations targeted by HEV, and the role of animals as potential vectors of the virus.

Diagnosis of noncultivatable gastroenteritis viruses, the human caliciviruses

Gastroenteritis is one of the most common illnesses of humans, and many different viruses have been causally associated with this disease. Of those enteric viruses that have been established as etiologic agents of gastroenteritis, only the human caliciviruses cannot be cultivated in vitro. The cloning of Norwalk virus and subsequently of other human caliciviruses has led to the development of several new diagnostic assays. Antigen detection enzyme immunoassays (EIAs) using polyclonal hyperimmune animal sera and antibody detection EIAs using recombinant virus-like particles have supplanted the use of human-derived reagents, but the use of these assays has been restricted to research laboratories. Reverse transcription-PCR assays for the detection of human caliciviruses are more widely available, and these assays have been used to identify virus in clinical specimens as well as in food, water, and other environmental samples. The application of these newer assays has significantly increased the recognition of the importance of human caliciviruses as causes of sporadic and outbreak-associated gastroenteritis.

Approaches of the diagnosis of hepatitis viruses

Hepatitis virus infection occurs in close to a billion people worldwide at some point in their lifetimes. Hepatitis B and C viruses together account for infections in half a billion people and are considered the most carcinogenic of any known biological agent. The diagnostic approaches to detect hepatitis viruses are discussed.

Molecular characterization of a hepatitis E virus isolate from Namibia

Hepatitis E virus (HEV) causes sporadic and epidemic acute viral hepatitis in many developing countries. In Africa, hepatitis E has been documented by virus detection (reverse transcriptase polymerase chain reaction, RT-PCR) in Egypt, Chad, Algeria, Morocco and Tunisia. Cases of presumptive hepatitis E also have been documented by detection of antibody to HEV in the Sudan, Kenya, Ethiopia, Somalia, Djibouti and South Africa. Recently, we reported the recovery of 9 isolates of HEV from feces collected during an outbreak of jaundice in Namibia. These specimens were stored frozen for many years at the South African Institute for Medical Research awaiting new methods to determine the etiology of jaundice. HEV genomic sequences were detected by antigen-capture RT-PCR with primers that amplified 2 independent regions of the HEV genome (ORF-2 and ORF-3). To further characterize the HEV 83-Namibia isolates, we determined the nucleotide (nt) sequence of the 3' end of the capsid gene (296 of 1, 980 nt in ORF-2) and ORF-3 for 1 isolate. The capsid gene sequence shared 86% identity with the prototype Burma strain and up to 96% identity with other African strains at the (nt) level, and 99% identity with Burma or other Africa strains at the amino acid level. A 188 (nt) fragment amplified from ORF-3 was also highly homologous to other HEV but was too short for meaningful comparison. Phylogenetic analysis indicated that HEV 83-Namibia is closely related to other African isolates, and differs from Burmese, Mexican and Chinese HEV. These data link the HEV causing the 1983 Namibia outbreak to more recent HEV transmission in northern and sub-Saharan Africa, suggesting this subgenotype of HEV is firmly established throughout the continent.

Shift of hepatitis E virus RNA from hepatocytes to biliary epithelial cells during acute infection of rhesus monkey

Hepatitis E virus (HEV) has been considered to be the major cause of enterically transmitted non-A, non-B hepatitis in developing countries. However, little is known about viral replication and localization in the liver. The aim of this study was to examine the distribution of HEV-infected cells in experimentally infected animals. Seven captured wild rhesus monkeys were inoculated intravenously with faecal extract derived from a Myanmar strain of HEV. Animals were killed at different time-points of clinical illness: during early infection, during prehepatitis with viral-like particles in bile, during acute hepatitis and during convalescence. Intrahepatic localization of HEV was analysed using non-isotopic thymine dimer in situ hybridization (NITDISH). Both plus and minus strands of HEV RNA were found in hepatocytes during the early infection period. Staining in the submembranous cytoplasmic region of hepatocytes was observed. In the prehepatitis period, both plus and minus strand HEV RNAs appeared in the canalicular side of isolated bile epithelial cells. Subsequently, HEV RNA became universally distributed in the cytoplasm of medium-size bile epithelial cells. After recovery, HEV RNA disappeared.

Hepatitis E infection in children: study of an outbreak

BACKGROUND

Hepatitis E virus (HEV) is responsible for most of the hepatitis epidemics in the developing world and it frequently affects young adults. Therefore, common perception is that it does not affect children.

METHODS

A group of 20 school children (13 years old) were possibly exposed to hepatitis E virus infection during a 2 day trekking trip. Epidemiological and clinical information was correlated to the presence of the hepatitis E virus genome and antibodies to HEV structural and non-structural proteins found in the blood of the children, using polymerase chain reaction and line immunoassay techniques.

RESULTS

Ten children developed icteric hepatitis, seven prodrome-like illness without jaundice while three remained asymptomatic. Immunoglobulin M (IgM) antibodies to open reading frame (ORF)2 protein (pORF2) were detected in all 19 children tested, whereas 11 and 10 of the children were positive for IgM antibodies against ORF1 (pORF1) and ORF3 (pORF3) proteins, respectively. The rate of HEV infection was found to be 85%. Viraemia was observed in 11 children and was present in four of the seven anicteric patients (55%) compared with six of the nine (66%) icteric patients. One child without any symptom also had viraemia.

CONCLUSIONS

The data obtained indicate a high susceptibility of children for HEV infection and a frequently prolonged viraemia in those infected.

The impact of traveling to endemic areas on the spread of hepatitis E virus infection: epidemiological and molecular analyses

Traveling to endemic areas carries a risk of hepatitis E virus (HEV) infection, but no molecular analysis to document sources of infection is available. Eighteen (38%) of 47 patients with acute non-A, non-B, non-C hepatitis were positive for antibody to HEV (anti-HEV), and 9 (50%) of these were also positive for serum HEV RNA by polymerase chain reaction following reverse transcription. Only 1 (5%) of the 21 patients with acute hepatitis A was positive for HEV RNA. Travel to endemic areas (mostly to China; odds ratio, 22.2; 95% confidence interval, 4.7-105.8) and deeper jaundice (odds ratio, 5.2; 95% confidence interval, 1.01-27.2) were the only factors associated with HEV infection in multivariate analysis. The two HEV isolates from two patients who had traveled to China and the HEV isolate from a patient whose travel history was obscure formed a monophyletic group with the isolates from Guangzhou. The HEV isolates from our patients show a homology of 72% to 78% in nucleotide sequence with the Burma, Beijing, India, Pakistan, and Xiangjiang strains; a homology of 81% to 91% with the Guangzhou strains; and a homology of 76% with the Mexico strain. The close relationship between the Taiwan isolates and the Guangzhou strains was further supported by the short Kimura's two-parameter distances among them. In summary, HEV infection does occur in this area. Epidemiological and molecular analyses strongly indicate that most cases of HEV infection originated from travel to HEV-endemic areas.

Seroepidemiological study of an acute hepatitis E outbreak in Morocco

This study clearly shows that hepatitis E virus (HEV) was the major aetiological virus in an outbreak in the south of Morocco, in 1994. Acute hepatitis E was diagnosed using recombinant antigen-based enzyme immunoassays and reverse transcription polymerase chain reaction in 77.3% of patients. In the west of Morocco, 6.1% of controls were positive for anti-HEV IgG. The anti-HEV prevalence in patients was significantly higher than that of controls (84.0% vs. 6.1%) (P < 0.001). In healthy contacts residing in southern Morocco, 10.4% had anti-HEV IgG, indicating past HEV infection. Furthermore, HEV-specific IgM was associated with subclinical HEV infection in 9 contacts and was noted in 10 others who were convalescent. Faecal contamination of drinking water samples collected from the epidemic city was observed. It also appeared that primary infection with HEV accounted for more than 86% of the cases. A longitudinal study showed waning of anti-HEV antibodies in patients and healthy contacts six months after the initial testing. Subclinical HEV infection was significantly prevalent in a paediatric population younger than 10 years (P < 0.05). Our results also showed that anti-HEV IgG in healthy contacts decreased significantly after 30 years of age (P < 0.01), whereas the clinical acute HEV infection incidence increased significantly with age (P < 0.01). From this study, it appears that HEV is present in both the west and the south of Morocco.

DNA inoculation with a plasmid vector carrying the hepatitis E virus structural protein gene induces immune response in mice

The plasmid construct, pJHEV, containing the full-length open reading frame 2 (ORF-2) of hepatitis E virus (HEV) gene, expresses the HEV structural protein ORF-2 in Cos-7 cells under the control of a hCMV promoter. No ORF-2 protein could be detected in Cos-7 cells transfected with either vector alone or with a vector containing the ORF-2 of HEV in the incorrect orientation. The successful construct was further tested in BALB/c (H-2d) mice for the induction of an ORF-2 specific immune response. Intramuscular (i.m.) immunization of mice pretreated 24 h earlier with bupivacaine with the naked DNA construct elicited a humoral immune response in 80% and 100% of two separate groups of mice, respectively. No anti-ORF-2 responses were observed in mice immunized with the vector only. Sera from mice injected with pJHEV specifically recognized HEV ORF-2 structural protein expressed in recombinant baculovirus in an enzyme-linked-immunosorbent assay (ELISA) and Western blot. Anti-ORF-2 serum titers peaked at ca 1:5000 in the ELISA and 1:1000 in the Western blot. These titers have remained constant for over 12 months after the last boost of pJHEV. To our knowledge, this is the first report of the use of DNA-based immunization for the generation of an immune response to a HEV structural protein.

The role of hepatitis E virus infection among patients with acute viral hepatitis in southern Saudi Arabia

We investigated the etiology of acute sporadic viral hepatitis in southern Saudi Arabia in a series of 132 patients admitted with acute viral hepatitis. Of these cases, 108 (81.8%) were due to acute hepatitis A virus infection, of which 11 (8.3%) patients had been previously exposed to hepatitis E virus, and another 10 (7.6%) were chronic carriers of hepatitis B virus. Three cases (2.3%) were acute hepatitis B virus infection. The overall prevalence of hepatitis E IgG antibodies was found to be 9.1%. The remaining 21 (15.9%) patients were tested for hepatitis E IgM, EBV-VCA IgM and hepatitis C IgG antibodies by sensitive enzyme immunoassays. In none of them could hepatitis E IgM, EBV-VCA IgM or hepatitis C IgG antibodies be demonstrated, and these patients were thus considered as acute non-A, non-B hepatitis. Acute hepatitis C virus infection, however, could not be ruled out from this group. We therefore concluded that the majority of clinically apparent viral hepatitis cases were due to HAV, while HBV accounted for a small proportion of the cases. Clinically apparent HEV infection does not appear to be common in the population studied, since even those with serologic evidence of previous exposure to HEV did not recall a history suggestive of acute viral hepatitis.

Consecutive evaluation of immunoglobulin M and G antibodies against hepatitis E virus

Hepatitis E virus (HEV) infection is sporadic in the Guangzhou city southern China. However, the evaluation of antibodies to HEV during consecutive time periods after infection has not been reported. We utilized enzyme immunosorbent assay (ELISA) to defect IgM and IgG anti-HEV in consecutive serum specimens from patients with acute hepatitis E and compared that data with detection rates of IgM and IgG anti-HAV in patients with acute hepatitis A. IgM anti-HEV can be detected as early as 4 days after onset of disease symptoms in some patients. The detection rate of IgM anti-HEV is significantly higher in specimens collected within 4 weeks (95%) of onset than in those specimens collected 4 to 18 weeks after onset (67.6%) (P < 0.005). IgM anti-HEV had a similar pattern to IgM anti-HAV and can be used as a marker of acute HEV infection. In contrast with IgG anti-HAV, 56.8% of the specimens did not contain detectable levels of IgG anti-HEV (P < 0.005). One should be cautioned against making a diagnosis of HEV infection solely by the currently available assays for IgG anti-HEV. In conclusion, IgM anti-HEV can be used as a reliable and sensitive marker for recent HEV infection, but serum specimens should be collected within 4 weeks after onset of symptoms to avoid false-negative results. In contrast, we should be aware of the failure to develop IgG anti-HEV in some patients. These patients carry the risk of reinfection.

Hepatitis E

Hepatitis E has a world-wide distribution and causes substantial morbidity and mortality in some developing countries, particularly among pregnant women. Hepatitis E virus (HEV) has recently been cloned and sequenced, and new diagnostic tests have been developed. These tests have been used to begin to characterize the natural history and epidemiological features of HEV infection. Experimental vaccines have also been developed that offer the potential to prevent hepatitis E. However, much remains to be learned about HEV, including the mechanisms of transmission, the reservoir(s) of the virus, and the natural history of protective immunity in order to develop effective strategies to prevent this disease.

Acute viral hepatitis types E, A, and B singly and in combination in acute liver failure in children in north India

The aetiological agents responsible for, and the outcome of, acute liver failure were investigated prospectively in 44 children (29 males, 15 females) attending a tertiary health care facility in India. The children were between the ages of 2 months and 13 years. Studies for viral infections and other etiologies could be carried out in 40 patients. Specific aetiological labels were possible in 35 (87.5%) patients. Thirty (75%) had evidence of acute viral hepatitis. Acute hepatitis E virus (HEV) infection was found in a total of 18 children, with hepatitis A (HAV) in 16, hepatitis B in 5, and C in 1. Seven had isolated infection with hepatitis E, five with A, and four with B. Nine had both E and A infection. Superinfection of HEV was observed in a child with Indian childhood cirrhosis (ICC). Acute HEV infection was confirmed by immunoblot assay in all the patients and in eight of these, HEV-RNA was also detected in the serum. HAV was involved in 37.5% of cases with isolated infection in 10% (4 of 40). The aetiological factors associated with acute liver failure, apart from HAV and HEV, were other hepatotropic viruses (22.5%), Wilson's disease (5%), ICC (5%), and hepatotoxic drugs (7.5%). In five patients, no serological evidence of acute viral hepatitis could be found, neither did the metabolic screen yield any result. It was observed that enterically transmitted hepatitis viruses (HAV and HEV) were associated with 60% of acute hepatic failure in children. Mixed infection of HAV and HEV formed the single largest aetiological subgroup. In developing countries, where hepatitis A and E infections are endemic, severe complications can arise in the case of mixed infection. This may contribute to most of the mortality from acute liver failure during childhood.

Hepatitis E: an overview

Hepatitis E has a worldwide distribution and causes substantial morbidity and mortality in some developing countries, particularly among pregnant women. Hepatitis E virus (HEV) has recently been cloned and sequenced and new diagnostic tests have been developed; these tests have been used to begin to characterize the natural history and epidemiologic features of HEV infection. Experimental vaccines have also been developed that offer the potential to prevent hepatitis E. However, to develop effective strategies to prevent this disease, much remains to be learned about HEV, including the vehicles of transmission, the reservoir(s) of the virus, and the natural history of protective immunity.

Short-term IgM and IgG antibody responses to hepatitis E virus infection

53 adult patients with acute hepatitis caused by hepatitis E virus were identified by the presence of IgM antibody to hepatitis E virus, and followed for 12 months to evaluate the kinetics of anti-HEV antibodies. All but 1 female Kuwaiti patient were expatriate workers from the Indian subcontinent, temporarily working in Kuwait. Follow-up samples obtained at 1, 3, 6 and 12 months were evaluated for IgM and IgG antibodies to hepatitis E virus. IgM-class antibodies to hepatitis E virus were detectable in 12/27 (44%) patients at 1 months, in 0/26 at 3 months, in 0/8 at 6 months and 0/6 at 12 months. IgG antibodies to hepatitis E virus were detectable in 46/47 (98%) at onset, 26/27 (96%) at 1 month, in 26/29 (90%) at 3 months, 16/16 (100%) at 6 months and 8/8 (100%) at 12 months of follow-up. This study suggests that IgM antibodies to hepatitis E virus decline rapidly after an acute infection but IgG antibodies to hepatitis E virus persists for at least 1 year in many patients.

Seroepidemiology of hepatitis E virus in the Egyptian Nile Delta

The seroendemicity of hepatitis E virus (HEV) in an entire village population located in the Egyptain Nile Delta is described. Serum specimens were obtained from 68% of the total population of 1,850 villagers. The lack of serum specimen was greatest in the youngest age group (< 5). Commercially available enzyme immunoassays (EIA) for antibody to hepatitis A virus (anti-HAV), to hepatitis B virus core antigen (anti-HBc), to second-generation hepatitis C virus (anti-HCV) core and nonstructural antigen, and to hepatitis E virus (HEV) were used. Only repeated reactive sera were coded as positive. Stool specimens were examined for Schistosoma mansoni by the Kato method and standard methods for the examination of the liver and spleen by ultrasonography were used. Unadjusted for nonrespone, the seroprevalence of anti-HEV was 17.2% (SE +/- 1.1). Anti-HEV seroprevalence increased by age and was not associated statistically with any of the other viral markers including HCV. Anti-HAV seroprevalence was consistently > 95%, even in the youngest age group (< 5). The overall sero-endemicity of HEV was higher than reported elsewhere and appears not to have been introduced into the village population recently.

Hepatitis E virus infection in hemophiliacs

Israel is endemic for hepatitis E virus (HEV), the causative agent of enteric non-A, non-B hepatitis. Transmission is via the feco-oral route but the possibility of transmission through blood transfusion has been raised. This question was addressed by examining sera from 188 hemophilic patients in Israel, screening was performed with an enzyme immunoassay (EIA) for antibody against hepatitis E virus (anti-HEV) and confirmed with a neutralization test. Sixteen patients (9%) were seropositive for anti-HEV. A statistically significant difference was not found between the seroprevalence in this group and that of a healthy Israeli control population, matched for sex and age. The anti-HEV-seropositive hemophiliacs had the same seroprevalence of antibodies to hepatitis B and C virus and to HIV and the same number of cases with chronic hepatitis as among the anti-HEV-seronegative patients. The seroprevalence of antibodies to hepatitis A virus (anti-HAV) was, on the other hand, higher in the anti-HEV-seropositive group. This study indicates that HEV is not transmitted by cryoprecipitate or lyophilized factor concentrates. High prevalence of coinfection with hepatitis A supports our conclusion that HEV infection in Israeli hemophiliacs was due mainly to feco-oral transmission.

Risk factors and prevalence of hepatitis E in German immigrants from the former Soviet Union

Worldwide there is only limited information on the epidemiology of hepatitis E virus (HEV) and its association with other hepatotropic viruses. Endemic regions have been described in some Asian countries, whereas in Europe only sporadic cases have been reported. The prevalence of HEV and a series of other viral hepatitis infections was investigated in a group of 1,025 individuals immigrating into Germany from the former Soviet Union. Serum samples were tested for anti-HEV by a commercial enzyme immunoassay (EIA) based on recombinant proteins, and by peptide EIA and immunoblot. Risk factors and other demographic information were investigated using a questionnaire and a short interview. The overall prevalence of anti-hepatitis E antibodies (anti-HEV) was 2.05%. The following risk factors for HEV infection were identified: age of > 65 years, resident in the south-west part of the former Soviet Union, history of hepatitis B virus (HBV) infection, and employment in health care professions. HEV prevalence is not strikingly different from that observed in Western European countries. However, the different rates found for HEV vs. hepatitis A virus (HAV) are intriguing, since similar routes of transmission (fecal-oral) are well documented for both viruses. Exposure to HBV is surprisingly high, and the number of hepatitis C virus (HCV)-positive individuals was also higher than those reported from Western European areas.

Serological evidence for hepatitis E virus infection in Israel

Israel is suspected to be endemic for hepatitis E virus (HEV) because of its geographic location and the large-scale immigration from endemic countries. Although no cases of local HEV infection have been diagnosed, a serological survey would provide indirect evidence for such infection. We examined sera from 1,416 healthy subjects, including 1,139 Jews from various regions of Israel and 277 Arabs, most of whom reside in the West Bank of the Jordan River. In addition, we tested 13 non-A, non-B, and non-C viral hepatitis patients. Sera were screened for antibody to hepatitis E virus (anti-HEV) by a newly developed enzyme immunoassay (EIA) and by immunoblots for both IgG and IgM anti-HEV activity. Positive samples were confirmed by neutralization. The seroprevalence found by EIA was 2.81% and 1.81% in the Jewish and Arab populations, respectively. More than a 2-fold higher prevalence in males compared to females and an increase with age were found in both populations. However, these differences were nonsignificant. The geographical distribution was even throughout the country, except for two clusters of 3 and 4 seropositive individuals possibly reflecting past foci of infection. Eight of 37 EIA-positive sera were positive for IgG, and 3 were positive for IgM by the immunoblot assay. Among hepatitis patients (9 acute and 4 chronic), one patient with chronic hepatitis was positive for both IgG and IgM. Our study provides indirect evidence that Israel is endemic for HEV.(ABSTRACT TRUNCATED AT 250 WORDS)

Etiology of acute sporadic hepatitis in adults in Senegal and Tunisia

Markers for acute hepatitis A, B, C and E virus infections were examined in the sera of 72 patients suffering from acute hepatitis in Senegal and Tunisia. Hepatitis B was responsible for 36% and hepatitis C for 21% of the cases. Acute hepatitis A was not diagnosed. HEV infection was not observed in Senegal and represents only 4% of the acute hepatitis cases in Tunisia.

Hepatitis E: A newcomer to the hepatitis alphabet - Case report and review of the literature

The first Canadian case of hepatitis E is described in a patient who travelled to Asia for a six-month period and spent most of his time in India. Hepatitis E shares some similarities with hepatitis A, notably the mode of transmission and the absence of chronic course. However, a few important differences have been noted, including a higher mortality rate and a high fatality rate in pregnant women. Hepatitis E is very common in developing countries and should be suspected more often in individuals with gastrointestinal complaints returning from endemic areas.

The role of hepatitis E virus in acute sporadic non-A, non-B hepatitis

Hepatitis E virus (HEV) is the cause of enterically transmitted non-A, non-B (NANB) hepatitis. Water-borne epidemics have been reported in many developing countries primarily affecting young and middle-aged adults. To determine the role of HEV in acute sporadic NANB hepatitis, we have studied the profiles of anti-HEV IgG in the sera of patients previously diagnosed for NANB hepatitis. We tested the sera of 53 patients with acute NANB hepatitis and 100 healthy people as a control group for anti-HEV IgG. Thirty-nine of the 53 patients (73.3%) and none of the control group were positive for HEV infection, according to results shown by ELISA. This result suggests that HEV is a common cause of acute sporadic NANB hepatitis in Turkey. Further studies are needed in the other regions to determine the true prevalence of HEV infection in Turkey.

Viral hepatitis in children with renal disease

Specific and sensitive diagnostic tests are now available to identify type A, B, C, D and E hepatitis. Hepatitis A and E which cause only acute, very rarely fulminant, hepatitis are spread largely by the faecal-oral route, having a brief viraemic phase. Hepatitis B, C and D which are transmitted parenterally and via secretions are often associated with chronic viraemia. Patients with chronic renal disease are at particular risk. Impaired immunity due to disease or drugs increases the propensity to develop a chronic carrier state which may progress to cirrhosis and hepatocellular carcinoma. Limited reports indicate that hepatitis C infection may cause cirrhosis more rapidly than hepatitis B. The emergence of mutants to both hepatitis B and C is a cause for concern. Treatment with interferon is of limited efficacy. Screening of blood products for viral markers and prudent handling of potentially infected materials to avoid contamination of damaged skin or mucous membrane are the best strategies to prevent infection. Hepatitis B vaccination of all newborns, young adolescents and those at risk is the most effective means of reducing the carrier frequency.

Acute sporadic hepatitis E in Kuwait

Fifty-seven adult patients with acute hepatitis and 34 comparison patients without liver disease were evaluated using a newly developed Western blot assay for IgM antibody to hepatitis E virus. The mean age of patients with hepatitis was 32 years (range, 18-55 years); 88% were male. Among patients with acute hepatitis, hepatitis A (anti-HAV IgM positive) was diagnosed in two (4%), hepatitis B (anti-HBc IgM positive) in three (5%), and hepatitis E (anti-HEV IgM positive) in 34 (60%). One hepatitis patient had CMV IgM, another had EBV IgM, and 16 others (28%) were negative for all serologic markers of acute viral hepatitis. No patient with acute hepatitis A or B and none of the comparison patients without acute hepatitis had anti-HEV IgM. All but one case of acute hepatitis E were found among expatriates of Asian origin, and acute hepatitis E was associated significantly with recent travel to the Indian subcontinent. These data suggest that acute hepatitis E is common among foreign workers in Kuwait but that little HEV transmission is occurring directly in Kuwait.

Three cases of acute hepatitis E virus infection imported into Norway

We report 3 cases of acute hepatitis E virus (HEV) infection imported from Asia. All 3 patients had fever and upper abdominal discomfort preceding jaundice which lasted 2-3 weeks with maximum bilirubin levels of 141-254 mmol/l. The ALT values peaked between 1,347 and 3,690 U/l. Both values normalized within 1-2 months. During the acute phase of the disease, all patients had high levels of IgG and IgM antibodies against HEV (anti-HEV) recombinant and synthetic peptides. The duration of the anti-HEV IgM was about 1-2 months.