Sero-prevalence and mother-to-infant transmission of hepatitis E virus among pregnant women in the United Arab Emirates

Hepatitis E: latest developments in knowledge

Hepatitis E, caused by Hepatitis E virus (HEV), is a highly prevalent disease in developing countries. In developed nations, autochthonous HEV infections seem to be an emergent disease. Its clinical manifestations and epidemiology are well known for endemic countries. It has been confirmed that hepatitis E is a zoonosis and that parenteral transmission can also occur. The molecular mechanisms of HEV replication are not fully understood, mostly because there are no efficient cell culture systems. HEV can cause chronic hepatitis in organ transplant recipients and immunocompetent patients. Cases with fulminant hepatitis and other extrahepatic manifestations have also been reported. The diagnosis is based on serological studies and detection of HEV RNA in blood and feces. Treatment with ribavirin and/or pegylated-IFN-α have proven to be successful in some cases. The recently approved/marketed vaccine is a good option in order to prevent this infection.

Chronic Infection With Camelid Hepatitis E Virus in a Liver Transplant Recipient Who Regularly Consumes Camel Meat and Milk

There have been increasing reports of food-borne zoonotic transmission of hepatitis E virus (HEV) genotype 3, which causes chronic infections in immunosuppressed patients. We performed phylogenetic analyses of the HEV sequence (partial and full-length) from 1 patient from the Middle East who underwent liver transplantation, and compared it with other orthohepevirus A sequences. We found the patient to be infected by camelid HEV. This patient regularly consumed camel meat and milk, therefore camelid HEV, which is genotype 7, might infect human beings. Our finding links consumption of camel-derived food products to post-transplantation hepatitis E, which, if detected at early stages, can be cured with antiviral therapy and reduced administration of immunosuppressive agents.

Extended Microbiological Characterization of Göttingen Minipigs in the Context of Xenotransplantation: Detection and Vertical Transmission of Hepatitis E Virus

Xenotransplantation has been proposed as a solution to the shortage of suitable human donors. Pigs are currently favoured as donor animals for xenotransplantation of cells, including islet cells, or organs. To reduce the xenotransplantation-associated risk of infection of the recipient the pig donor should be carefully characterised. Göttingen minipigs from Ellegaard are often used for biomedical research and are regularly tested by their vendor for the presence of numerous bacteria, fungi, viruses and parasites. However, screening for some pathogens transmittable to humans had not been performed.The presence of microorganisms was examined in Göttingen Minipigs by PCR methods. Since zoonotic transmission of porcine hepatitis E virus HEV to humans has been demonstrated, extended search for HEV was considered as a priority. RNA from sera, islet and other cells from 40 minipigs were examined for HEV using different real-time reverse transcription (RT)-PCRs, among them two newly established. In addition, sera were examined by Western blot analysis using two recombinant capsid proteins of HEV as antigens. HEV RNA was not detected in pigs older than one year including gilts, but it was detected in the sera of three of ten animals younger than 1 year. Furthermore, HEV was also detected in the sera of three sows six days after delivery and their offspring, indicating vertical transmission of the virus. PCR amplicons were cloned, sequenced and the viruses were found to belong to the HEV genotype (gt) 3/4. Anti-HEV immunoglobulins G were detected in one sow and maternal antibodies in her six day old piglet. Since Göttingen minipigs were negative for many xenotransplantation-relevant microorganisms, they can now be classified as safe. HEV may be eliminated from the Ellegaard herd by selection of negative animals and/or by treatment of the animals.

Experimental infection of pregnant rabbits with hepatitis E virus demonstrating high mortality and vertical transmission

A high mortality rate of approximately 20% in pregnant women with hepatitis E has been reported in previous studies. However, other studies showed no difference between pregnant and nonpregnant women in the severity of hepatitis E. To determine the effects of HEV infection on pregnancy, we successfully established HEV infection in six pregnant rabbits (PR) and six nonpregnant rabbits (NPR) with a rabbit HEV isolate, taking three PR and one NPR without HEV infection as controls. Tests for HEV RNA by RT-PCR, anti-HEV antibodies by ELISA and HEV antigen via immunohistochemistry and histopathology were carried out. Two of six infected PR miscarried and three of the remaining four PR died which may be attributed to severe liver necrosis caused by HEV infection. Moreover, vertical transmission was found to be associated with the replication of HEV in placenta, indicated by the presence of HEV RNA and antigen in placenta from the infected PR. Our findings strongly suggest that HEV infection could lead to adverse outcomes in pregnancy and vertical transmission, suggesting the necessity for pregnant women at risk of HEV infection to be vaccinated.

A Study of Hepatitis E in Pregnancy: Maternal and Fetal Outcome

PURPOSE

HEV infection, a major public health concern, is known to cause large-scale epidemic and sporadic cases of acute viral hepatitis in developing countries. The infection occurs primarily in young adults and is generally mild and self-limiting; however, the case fatality rate is reportedly higher among women, especially during the second or third trimesters of pregnancy.

METHODS

This study, a prospective observational study, was conducted at the Dr. D. Y. Patil Medical College Hospital and Apple Saraswati Multispeciality hospital, in Kolhapur for over a period of 3 years (Jan 2010 to Jan 2013) to find out the prevalence and clinical outcome in a series of HEV-infected pregnant women.

RESULTS

A total of fifty-five symptomatic Anti-HEV IgM-positive women were included, and the maternal-fetal outcome was analyzed. The maternal mortality was 5 % including one antenatal death. Prematurity (80 %) and PROM (11 %) were the commonest fetal complications noted with a vertical transmission rate of 28 %.

CONCLUSION

Variations in maternal morbidity and mortality between different studies indicate a need to subtype the viral genotype according to its virulence and morbidity.

Hepatitis E virus in the countries of the Middle East and North Africa region: an awareness of an infectious threat to blood safety

PURPOSE

Hepatitis E virus (HEV) is mainly transmitted through contaminated water supplies which make the virus endemic in developing countries including countries of the Middle East and North Africa (MENA) region. Recent reports suggest potential risk of HEV transmission via blood transfusion.

METHODS

Related articles on HEV were collected by searching through the 25 countries of the MENA region using Pubmed and Medline within the past 14 years: January 2000-August 2014.

RESULTS

One hundred articles were extracted, of which 25 were not eligible. The articles discussed the seroprevalence of HEV and HEV markers in 12 countries. Eight articles provided data on HEV in blood donors. The seroprevalence of HEV in the general MENA population ranged from 2.0 to 37.5% and was higher in males than in females. Prevalence increased with age, but exposure seems to be in early life.

CONCLUSIONS

In the MENA region, the role of HEV as an infectious threat to blood safety is under-investigated. More data are needed to quantify the risk of transmission and to assess clinical outcomes. This requires, at least, surveillance screening of donors and recipients for HEV markers using sensitive and specific serological tests. At the present time, serious consideration should be given to selective screening for certain groups of patients (e.g., immunocompromised, pregnant women and others) who commonly require blood transfusion and are at high risk of hepatic failure or chronicity from HEV infection.

High prevalence of hepatitis e virus in Swedish moose--a phylogenetic characterization and comparison of the virus from different regions

BACKGROUND

Hepatitis E virus (HEV) infects a range of species, including humans, pigs, wild boars and deer. Zoonotic transmission may contribute to the high HEV seroprevalence in the human population of many countries. A novel divergent HEV from moose (Alces alces) in Sweden was recently identified by partial genome sequencing. Since only one strain was found, its classification within the HEV family, prevalence in moose and zoonotic potential was unclear. We therefore investigated samples from 231 moose in seven Swedish counties for HEV, and sequenced a near complete moose HEV genome. Phylogenetic analysis to classify this virus within the family Hepeviridae and to explore potential host specific determinants was performed.

METHODS AND FINDINGS

The HEV prevalence of moose was determined by PCR (marker for active infection) and serological assays (marker of past infection) of sera and 51 fecal samples from 231 Swedish moose. Markers of active and past infection were found in 67 (29%) animals, while 34 (15%) were positive for HEV RNA, 43 (19%) were seropositive for anti-HEV antibodies, and 10 (4%) had both markers. The number of young individuals positive for HEV RNA was larger than for older individuals, and the number of anti-HEV antibody positive individuals increased with age. The high throughput sequenced moose HEV genome was 35-60% identical to existing HEVs. Partial ORF1 sequences from 13 moose strains showed high similarity among them, forming a distinct monophyletic clade with a common ancestor to HEV genotype 1-6 group, which includes members known for zoonotic transmission.

CONCLUSIONS

This study demonstrates a high frequency of HEV in moose in Sweden, with markers of current and past infection demonstrated in 30% of the animals. Moose is thus an important animal reservoir of HEV. The phylogenetic relationship demonstrated that the moose HEV belonged to the genotype 1-6 group, which includes strains that also infect humans, and therefore may signify a potential for zoonotic transmission of this HEV.

Xenotransplantation and Hepatitis E virus

Xenotransplantation using pig cells, tissues and organs may be associated with the transmission of porcine microorganisms to the human recipient. Some of these microorganisms may induce a zoonosis, that is an infectious disease induced by microorganisms transmitted from another species. With exception of the porcine endogenous retroviruses (PERVs), which are integrated in the genome of all pigs, the transmission of all other microorganisms can be prevented by specified or designated pathogen-free (spf or dpf, respectively) production of the animals. However, it is becoming clear in the last years that the hepatitis E virus (HEV) is one of the viruses which are difficult to eliminate. It is important to note that there are differences between HEV of genotypes (gt) 1 and gt2 on one hand and HEV of gt3 and gt4 on the other. HEV gt1 and gt2 are human viruses, and they induce hepatitis and in the worst case fatal infections in pregnant women. In contrast, HEV gt3 and gt4 are viruses of pigs, and they may infect humans, induce commonly only mild diseases, if any, and are harmless for pregnant women. The goal of this review was to evaluate the risk posed by HEV gt3 and gt4 for xenotransplantation and to indicate ways of their elimination from pigs in order to prevent transmission to the human recipient.

Association of cytokines in hepatitis E with pregnancy outcome

AIMS

The aim of this study was to evaluate tumour necrosis factor-alpha (TNF-α), interleukin (IL)-6, interferon gamma (IFN-γ) and transforming growth factor-beta1 (TGF-β1) in hepatitis E infection during pregnancy and its relation with pregnancy outcome.

METHODS

A total of 272 pregnant and 219 non-pregnant women with hepatitis and 262 age and gestational age matched healthy pregnant women and 208 age matched, healthy non-pregnant women were evaluated on the basis of history, clinical examination, liver function profile. Serological tests of hepatitis A, B, C and E and cytokines using commercially available (ELISA) kits. The patients with hepatitis E were further evaluated for viral load by Real Time PCR. All these were followed till delivery for pregnancy outcome.

RESULTS

HEV viral load in acute viral hepatitis (AVH) and fulminant hepatic failure (FHF) of pregnant women were comparatively higher than non-pregnant women. Significantly higher levels of TNF-α, IL-6, IFN-γ and TGF-β1 were present in HEV infected pregnant women compared to non-pregnant women and controls. TNF-α, IL-6 and IFN-γ had significant positive correlation with viral load, serum bilirubin and prothrombin time in pregnant women. Higher levels of all four cytokines were found in pregnant women with HEV infection having adverse pregnancy outcome compared to that of pregnant women with non-HEV infection and controls.

CONCLUSION

In conclusion, severity of HEV infection and associated adverse pregnancy outcome might be mediated by cytokine in pregnancy.

Transmission, diagnosis, and management of hepatitis E: an update

Hepatitis E virus (HEV) infection is an important public health concern in many developing countries, causing waterborne outbreaks as well as sporadic autochthonous hepatitis. HEV is mainly transmitted by the fecal–oral route in endemic areas through drinking of contaminated water. However, zoonotic transmission from animal reservoirs to humans has also been suggested. Three additional routes of HEV transmission have been proposed to occur: blood borne, human to human, and vertical transmission from mother to child. Acute HEV infection is usually diagnosed by detecting specific anti-HEV antibodies. However, the performance of the available assays in different settings is not optimal. Analysis of HEV ribonucleic acid in biologic specimens such as stools, serum, and liver biopsy by using nucleic acid amplification techniques is also employed. Nonetheless, additional consensus regarding the best technologies suitable for serosurveys and diagnosis of acute HEV infection is also needed. This review article summarizes the current status of HEV infection end epidemiology with particular emphasis in transmission, diagnosis, and clinical management.

Maternal-Fetal Hepatitis E Transmission: Is It Underestimated?

Hepatitis E virus (HEV) is an enterically transmitted virus; and several modes of transmission have been proposed, including blood transfusion, person to person transmission, and transplacental transmission. HEV during pregnancy is associated with an unfavorable prognosis for mothers and in severe cases can cause acute fulminate hepatitis and death. Transplacental transmission of HEV usually results in unfavorable outcomes of pregnancy, mainly fetal loss, preterm labor, and hepatic dysfunction in neonates. In this review, we will summarize the effects of HEV on maternal-fetal health in various clinical situations.

A systematic review of hepatitis E virus infection in children

A systematic review was conducted, seeking all literature relevant to the epidemiology, clinical and laboratory features, and outcome of hepatitis E virus (HEV) infection in children. Transmission is thought to be primarily from fecal-oral transmission, with the role of transmission from animal reservoirs not being clear in children. Worldwide, seroprevalence is <10% up to 10 years of age, with the exception of 1 of 5 studies from India and the sole study from Egypt. Seroprevalence increases with age, but it is not clear if it is increasing over time. The clinical presentation of HEV infection has broad similarities to hepatitis A virus (HAV) infection, with most cases being subclinical. However, HEV differs from HAV in that infectivity is lower, perinatal transmission can result in neonatal morbidity and even mortality, and a chronic carrier state exists, accounting for chronic hepatitis in some pediatric solid organ transplant recipients.

Hepatitis E: an emerging disease

Currently, the infection with the hepatitis E virus represents the most frequent cause for acute hepatitis and jaundice in the world. According to WHO estimations, around two billion people, representing one third of the world's population, live in endemic areas for HEV and, therefore, are at risk of infection. In developed countries, the circulation of the virus in both human and animal (swine, boar, deer) sewage has been confirmed; however, the incidence rate is low compared to that of developing countries where outbreaks of acute hepatitis transmitted via the fecal-oral route are originated, more frequently in the flooding season or after natural disasters, combined with deficient sanitary conditions. There are currently 4 known genotypes of HEV. Genotypes 1 and 2 are isolated in all human epidemic outbreaks in developing countries, while genotypes 3 and 4 are isolated not only in humans but also in animals, in both developing and industrialized countries. These data support genotypes 3 and 4 having zoonotic nature. The diagnosis of this disease is based in the detection of anti-HEV IgG and IgM in blood serum using enzyme-linked immunosorbent methods. However, the method that best confirms the diagnosis is the RT-PCR, which detects HEV RNA in blood serum and also provides the genotype. The clinical course is generally that of an acute hepatitis which in some cases may require hospitalization and that, in transplant patients or HIV infected individuals can become a chronic hepatitis. Furthermore, the virus constitutes an important risk for pregnant women. The hepatitis E can present a wide range of symptoms, from a subclinical case to chronic liver disease with extrahepatic manifestations. For this reason, the diagnostic is challenging if no differential diagnosis is included. There is no specific antiviral drug for hepatitis E, but satisfactory results have been observed in some patients treated with pegylated interferon alfa2a and/or ribavirin. This revision is an update of all the molecular, epidemiological, clinic and preventive knowledge on this emergent disease up to date.

An outbreak of hepatitis E and high maternal mortality at Port Sudan, Eastern Sudan

During 4 months (November 2010-March 2011) of an outbreak of hepatitis E virus (HEV), 39 pregnant women presented at Port Sudan Hospital, Sudan, with various symptoms of viral hepatitis. The diagnosis of viral hepatitis was confirmed by serology using ELISA anti-HEV IgG and IgM. The mean (SD) maternal age and gestational age were 24·0 (4·2) years and 33·6 (3·7) weeks, respectively. Eight (20·5%) women were primigravidae. There were 11 (28·2%) maternal deaths, 14 (36·0%) intrauterine fetal deaths, and eight (20·5%) cases of postpartum haemorrhage. There were nine (23·0%) cases of preterm (<37 weeks of gestation) deliveries. Fulminant hepatitis with hepatic encephalopathy was the most common cause of death among these patients. Nine of these women died before delivery and the other two died immediately following the delivery due to severe haemorrhage. There were no significant differences in clinical and biochemical data between the women who died (11) and those who survived.

Clinicolaboratory study of mother-to-neonate transmission of hepatitis E virus in Egypt

OBJECTIVES

To study the presence of hepatitis E viremia in neonates with congenital infections.

METHODS

We included 29 neonates with clinical signs and symptoms suggesting congenital infections, along with their mothers. The control group comprised 29 healthy neonates and their mothers. Laboratory evaluations were performed for each sample for liver function profiles and virological studies for hepatitis viruses B, C, and E.

RESULTS

The most common viral markers in mothers were for hepatitis C immunoglobulin G (IgG) (41%), followed by hepatitis B surface antigen (34%) and hepatitis E virus (HEV) IgG (31%). The most common presentations in neonates were respiratory distress syndrome, followed by preterm birth and signs of sepsis (both 41%) and hepatosplenomegaly (13%).

CONCLUSIONS

This study highlights the occurrence of HEV infection among other etiological conditions causing congenital infections. Vertical transmission from mothers was common in our patients. Although HEV ran a milder course, more studies are needed.

Hepatitis e and acute liver failure in pregnancy

Hepatitis E virus is a positive strand RNA virus with three open reading frames which is transmitted predominantly through the fecal contamination of water and food. It is the most common cause of acute liver failure in endemic areas. Pregnant women especially from the Indian subcontinent and Africa are at increased risk of contracting acute HEV infection as well as developing severe complications including ALF. Transmission of HEV occurs from mother to unborn child. Both maternal and fetal complications may occur, including abortion, fetal demise, preterm labor and maternal or neonatal death. The precise reasons for increased susceptibility to HEV infection during pregnancy and associated severe disease are still an enigma. Management is supportive and termination of pregnancy is not recommended as a general rule. Prevention of infection is of vital importance, as availability of clean drinking water can reduce the burden of this disease in the community. There is a need for future research to focus on prevention of ALF in pregnancy and to study the disease pathogenesis, which is not explicitly understood at present. The availability of a vaccine may alter the natural course of the disease in this select population which is at risk.

Epidemiology of mammalian hepatitis E virus infection

Mammalian hepatitis E virus (HEV), the etiological agent of hepatitis E in humans, is a recently discovered infectious agent. It was identified for the first time in 1983 using electron microscopy on a faecal specimen of a person infected with non-A, non-B enterically-transmitted hepatitis. Based on retrospective and prospective studies, HEV was long described as one of the leading causes of acute viral hepatitis in tropical and subtropical countries, whereas in developed countries hepatitis E was considered an imported disease from HEV hyperendemic countries. Data from studies conducted during the past decade have greatly shifted our knowledge on the epidemiology and clinical spectrum of HEV. Recently, it has been shown that contrary to previous beliefs, hepatitis E is also an endemic disease in several developed countries, particularly in Japan and in Europe, as evidenced by reports of high anti-HEV immunoglobulin G prevalence in healthy individuals and an increasing number of non-travel-related acute hepatitis E cases. Moreover, a porcine reservoir and growing evidence of zoonotic transmission have been reported in these countries. This review summarizes the current knowledge on the epidemiology and prevention of transmission of mammalian HEV.

Liver disease in pregnancy

Changes in the liver biochemical profile are normal in pregnancy. However, up to 3% to 5% of all pregnancies are complicated by liver dysfunction. It is important that liver disease during pregnancy is recognized because early diagnosis may improve maternal and fetal outcomes, with resultant decreased morbidity and mortality. Liver diseases that occur in pregnancy can be divided into 3 different groups: liver diseases that are unique to pregnancy, liver diseases that are not unique to pregnancy but can be revealed or exacerbated by pregnancy, and liver diseases that are unrelated to but occur coincidentally during pregnancy.

Prevalence of hepatitis e virus in swine fed on kitchen residue

The aim of this study was to investigate the prevalence of swine hepatitis E virus (HEV) in pigs fed different feedstuffs (kitchen residue or mixed feeds) and genetic identification of HEV isolated in Hebei province, China. Serum and fecal samples were collected from adult swine. Anti-HEV antibody was evaluated by double sandwich antigen enzyme immunoassay. HEV RNA was extracted from fecal samples and amplified by nested RT-PCR. The reaction products were sequenced, and the sequence analyzed. Virus-like particles were distinguishable by negative staining in the electron microscope. Histopathological observation and immunohistochemical localization were used in the animal models. Overall, the anti-HEV positive percentage of serum samples from pigs fed on kitchen residue was 87.10% (27/31), and 53.06% (130/245) from pigs fed on complete feed. The HEV RNA positivity rate of fecal samples from pigs fed on kitchen residue was 61.54% (8/13), but zero for pigs fed on complete feed. Sequence analysis of these eight samples and comparison with the published sequence showed that there were eight groups that belonged to genotype 4 d and the nucleotide identity was 95.6–99.3%. swHE11 is most closely related to strain CCC220, and the other seven HEV isolates were most closely related to strains swGX40, SwCH189 and V0008ORF3, which are isolates from human and pigs. Histopathological observation showed that there was liver damage in the experimental group, and immunohistochemistry indicated that the HEV antigens were strongly positive at 7 days after infection. The results demonstrated that the prevalence of HEV in pigs fed on kitchen residue was higher than in those fed on complete feed (P<0.05).

Fatal outbreaks of jaundice in pregnancy and the epidemic history of hepatitis E

Space-time clustering of people who fall acutely ill with jaundice, then slip into coma and death, is an alarming phenomenon, more markedly so when the victims are mostly or exclusively pregnant. Documentation of the peculiar, fatal predisposition of pregnant women during outbreaks of jaundice identifies hepatitis E and enables construction of its epidemic history. Between the last decade of the 18th century and the early decades of the 20th century, hepatitis E-like outbreaks were reported mainly from Western Europe and several of its colonies. During the latter half of the 20th century, reports of these epidemics, including those that became serologically confirmed as hepatitis E, emanated from, first, the eastern and southern Mediterranean littoral and, thereafter, Southern and Central Asia, Eastern Europe, and the rest of Africa. The dispersal has been accompanied by a trend towards more frequent and larger-scale occurrences. Epidemic and endemic hepatitis E still beset people inhabiting Asia and Africa, especially pregnant women and their fetuses and infants. Their relief necessitates not only accelerated access to potable water and sanitation but also vaccination against hepatitis E.

Liver disease in pregnancy

This article briefly discusses gestational physiologic changes and thereafter reviews liver diseases during pregnancy, which are divided into 3 main categories. The first category includes conditions that are unique to pregnancy and generally resolve with the termination of pregnancy, the second category includes liver diseases that are not unique to the pregnant population but occur commonly or are severely affected by pregnancy, and the third category includes diseases that occur coincidentally with pregnancy and in patients with underlying chronic liver disease, with cirrhosis, or after liver transplant who become pregnant.

The incidence of hepatitis E virus infection in the general population of the USA

Hepatitis E virus (HEV) infection is as an emerging disease of global importance because it is one of the major causes of acute hepatitis worldwide. There are few reports on the incidence of HEV in the USA. For better assessing the burden of primary HEV infection as well as understanding the epidemiology of HEV in the US population this analysis was conducted to estimate the force of infection of HEV in the USA. HEV force of infection in the general US population was calculated using catalytic models as cumulative markers of past infection from HEV seroprevalence data from the NHANES Survey. In the US population the force of infection was seven infections per 1000 susceptible persons per year. This study shows that in the USA HEV can be acquired locally and from developing countries. HEV is circulating more frequently in the non-Hispanic White racial/ethnic group and those who consume fish more frequently.

Seroepidemiology of hepatitis A and hepatitis E viruses in Aden, Yemen

The burden of hepatitis A (HAV) and hepatitis E (HEV) infection is unknown in Aden, Yemen. This survey describes the prevalence of antibodies against HAV and HEV among individuals attending primary health care facilities in Aden, Yemen. Five hundred and thirty eight participants, stratified by age and district population size, were enrolled and screened for anti-HAV and 356 for anti-HEV antibodies. The age-standardized seroprevalence of antibodies was 86.6% (95% CI 83.7-89.5) for anti-HAV and 10.7% (95% CI 7.5-13.9) for anti-HEV. The prevalence of anti-HAV and anti-HEV ranged from 53% and 0% in infants to 100% and 15.3% in participants >18 years old, respectively (P<0.001). Viral hepatitis remains a major public health problem in Aden with trends of hyperendemicity for both infections. Priority should be given to improve water quality, sanitation coverage, and food hygiene and increase public health awareness concerning the risk of contracting infection.

Liver disease in pregnancy

Severe liver disease in pregnancy is rare. Pregnancy-related liver disease is the most frequent cause of liver dysfunction in pregnancy and provides a real threat to fetal and maternal survival. A rapid diagnosis differentiating between liver disease related and unrelated to pregnancy is required in women who present with liver dysfunction during pregnancy. Research has improved our understanding of the pathogenesis of pregnancy-related liver disease, which has translated into improved maternal and fetal outcomes. Here, we provide an overview of liver diseases that occur in pregnancy, an update on the key mechanisms involved in their pathogenesis, and assessment of available treatment options.

Infections in Pregnancy

Despite advances in peripartum care, maternal morbidity and mortality associated with infections in pregnancy are increasing even in developed countries. Recently published data from the Center for Disease Control's Pregnancy Mortality Surveillance System indicates that although maternal mortality from hemorrhage, embolism, and anesthesia has declined in the United States, the proportion of maternal deaths due to infections has increased. During 1991–7 infection accounted for 13.2% of pregnancy-related deaths overall and 36.3% of abortion-related deaths. The greatest infection risk is found in blacks, older women, women without prenatal care, and women with multiple pregnancy. In the United States pregnancy rates are stable or increasing in these groups. Infection is also a major cause of morbidity and mortality for the fetus and newborn. Many perinatal infections are associated with intra-uterine growth retardation and low birthweight, or cause fetal and neonatal brain injury. Infections, particularly bacterial vaginosis and chorioamnionitis, can result in preterm delivery of live-born infants (delivery before 37 weeks gestation), or stillbirth. A multitude of immunologic, endocrinologic, metabolic, physiologic, and anatomic changes influence the likelihood and course of many infections during pregnancy. Some of these changes are intrinsic, and occur in all normal pregnancies, while others occur to varying degrees in normal and abnormal pregnancies.

Hepatitis E virus infection is highly prevalent among pregnant women in Accra, Ghana

Background

Hepatitis E virus (HEV) is highly endemic in several African countries with high mortality rate among pregnant women. The prevalence of antibodies to HEV in Ghana is not known. Therefore we evaluated the prevalence of anti-HEV IgG and anti-HEV IgM among pregnant women seen between the months of January and May, 2008 at the Obstetrics and Gynaecology Department, Korle-Bu Teaching Hospital, Accra, Ghana.

Results

One hundred and fifty-seven women provided blood samples for unlinked anonymous testing for the presence of antibodies to HEV. The median age of participants was 28.89 ± 5.76 years (range 13–42 years). Of the 157 women tested, HEV seroprevelance was 28.66% (45/157). Among the seropositive women, 64.40% (29/45) tested positive for anti-HEV IgM while 35.60% (16/45) tested positive to HEV IgG antibodies. HEV seroprevalence was highest (46.15%) among women 21–25 years of age, followed by 42.82% in = 20 year group, then 36.84% in = 36 year group. Of the 157 women, 75.79% and 22.92% were in their third and second trimesters of pregnancy, respectively. Anti-HEV antibodies detected in women in their third trimester of pregnancy (30.25%) was significantly higher, P < 0.05, than in women in their second trimester of pregnancy (25.0%).

Conclusion

Consistent with similar studies worldwide, the results of our studies revealed a high prevalence of HEV infection in pregnant women.

Clinical course and duration of viremia in vertically transmitted hepatitis E virus (HEV) infection in babies born to HEV-infected mothers

Infection with the hepatitis E virus (HEV) causes a self-limiting acute hepatitis. However, prolonged viremia and chronic hepatitis has been reported in organ transplant recipients. Vertically transmitted HEV infection is known to cause acute hepatitis in newborn babies. The clinical course and duration of viremia in vertically transmitted HEV infection in neonates in not known. We studied 19 babies born to HEV infected mothers. Babies were studied at birth and on a monthly basis to evaluate clinical profile, pattern of antibody response and duration of viremia in those infected with HEV. Fifteen (78.9%) babies had evidence of vertically transmitted HEV infection at birth (IgM anti-HEV positive in 12 and HEV RNA reactive in 10) and three had short-lasting IgG anti-HEV positivity because of trans-placental antibody transmission. Seven HEV-infected babies had icteric hepatitis, five had anicteric hepatitis and three had high serum bilirubin with normal liver enzymes. Seven babies died in first week of birth (prematurity 1, icteric HEV 3, anicteric HEV 2 and hyperbilirubinemia 1). Nine babies survived and were followed up for clinical, biochemical, serological course and duration of viremia. Five of 9 babies who survived were HEV RNA positive. HEV RNA was not detectable by 4 weeks of birth in three babies, by 8 weeks in one and by 32 weeks in one. All surviving babies had self-limiting disease and none had prolonged viremia. Thus HEV infection is commonly transmitted from mother-to-foetus and causes high neonatal mortality. HEV infection in survivors is self-limiting with short lasting viremia.

Hepatitis E: a complex and global disease

Thirty years after its discovery, the hepatitis E virus (HEV) continues to represent a major public health problem in developing countries. In developed countries, it has emerged as a significant cause of non-travel-associated acute hepatitis. HEV infects a wide range of mammalian species and a key reservoir worldwide appears to be swine. Genomic sequence similarity between some human HEV genotypes and swine HEV strains has been identified and we know that humans can acquire HEV infection from animals. Although for the most part the clinical course of HEV infection is asymptomatic or mild, significant risk of serious disease exists in pregnant women and those with chronic liver disease. In addition, there are data on the threat of chronic infections in immunocompromised patients. Beyond management of exposure by public health measures, recent data support that active immunisation can prevent hepatitis E, highlighting the need for vaccination programmes. Here we review the current knowledge on HEV, its epidemiology, and the management and prevention of human disease.

Hepatitis E and pregnancy: understanding the pathogenesis

Hepatitis E virus (HEV) is a single-stranded RNA virus that causes large-scale epidemics of acute viral hepatitis, particularly in developing countries. In men and non-pregnant women, the disease is usually self-limited and has a case-fatality rate of less than <0.1%. However, in pregnant women, particularly from certain geographical areas in India, HEV infection is more severe, often leading to fulminant hepatic failure and death in a significant proportion of patients. In contrast, reports from Egypt, Europe and the USA have shown that the course and severity of viral hepatitis during pregnancy is not different from that in non-pregnant women. The reasons for this geographical difference are not clear. The high mortality rate in pregnancy has been thought to be secondary to the associated hormonal (oestrogen and progesterone) changes during pregnancy and consequent immunological changes. These immunological changes include downregulation of the p65 component of nuclear factor (NF-kappaB) with a predominant T-helper type 2 (Th2) bias in the T-cell response along with host susceptibility factors, mediated by human leucocyte antigen expression. Thus far, researchers were unable to explain the high HEV morbidity in pregnancy, why it is different from other hepatitis viruses such as hepatitis A with similar epidemiological features and the reason behind the difference in HEV morbidity in pregnant women in different geographical regions. The recent developments in understanding the immune response to HEV have encouraged us to review the possible mechanisms for these differences. Further research in the immunology of HEV and pregnancy is required to conquer this disease in the near future.

Hepatitis E and pregnancy: understanding the pathogenesis

Hepatitis E virus (HEV) is a single-stranded RNA virus that causes large-scale epidemics of acute viral hepatitis, particularly in developing countries. In men and non-pregnant women, the disease is usually self-limited and has a case-fatality rate of less than <0.1%. However, in pregnant women, particularly from certain geographical areas in India, HEV infection is more severe, often leading to fulminant hepatic failure and death in a significant proportion of patients. In contrast, reports from Egypt, Europe and the USA have shown that the course and severity of viral hepatitis during pregnancy is not different from that in non-pregnant women. The reasons for this geographical difference are not clear. The high mortality rate in pregnancy has been thought to be secondary to the associated hormonal (oestrogen and progesterone) changes during pregnancy and consequent immunological changes. These immunological changes include downregulation of the p65 component of nuclear factor (NF-kappaB) with a predominant T-helper type 2 (Th2) bias in the T-cell response along with host susceptibility factors, mediated by human leucocyte antigen expression. Thus far, researchers were unable to explain the high HEV morbidity in pregnancy, why it is different from other hepatitis viruses such as hepatitis A with similar epidemiological features and the reason behind the difference in HEV morbidity in pregnant women in different geographical regions. The recent developments in understanding the immune response to HEV have encouraged us to review the possible mechanisms for these differences. Further research in the immunology of HEV and pregnancy is required to conquer this disease in the near future.

Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm

The objective of the present study was to determine the pattern of Hepatitis E virus (HEV) infection in a naturally infected, farrow-to-finish herd. For that purpose, a prospective study was conducted in randomly selected 19 sows and 45 piglets. Blood samples were collected from sows at 1 week post-farrowing and from piglets at 1, 3, 6, 9, 12, 15, 18 and 22 weeks of age. Furthermore 3 or 5 animals were necropsied at each bleeding day (but at 1 week of age), and serum, bile, liver, mesenteric lymph nodes and faeces taken. HEV IgG, IgM and IgA antibodies were determined in serum and viral RNA was analysed in all collected samples by semi-nested RT-PCR. Histopathological examination of mesenteric lymph nodes and liver was also conducted. From 13 analysed sows, 10 (76.9%) were positive to IgG, one to IgA (7.7%) and two to IgM (15.4%) antibodies specific to HEV. In piglets, IgG and IgA maternal antibodies lasted until 9 and 3 weeks of age, respectively. IgG seroconversion occurred by 15 weeks of age while IgM and IgA at 12. On individual basis, IgG was detectable until the end of the study while IgM and IgA antibody duration was of 4-7 weeks. HEV RNA was detected in serum at all analysed ages with the highest prevalence at 15 weeks of age. HEV was detected in faeces and lymph nodes for the first time at 9 weeks of age and peaked at 12 and 15 weeks of age. This peak coincided with the occurrence of hepatitis as well as with HEV detection in bile, liver, mesenteric lymph nodes and faeces, and also with highest IgG and IgM OD values at 15 weeks. Finally, different HEV sequences from this farm were obtained, which they clustered within 3 different groups, together with other Spanish sequences, all of them of genotype 3. Moreover, the present study also indicates that the same pig can be infected with at least two different strains of HEV during its productive life. This is the first study characterizing HEV infection in naturally infected pigs with chronological virus detection and its relationship with tissue lesions throughout the productive life of the animals.

Hepatitis E virus: molecular virology, clinical features, diagnosis, transmission, epidemiology, and prevention

Hepatitis E virus (HEV), the sole member of the genus Hepevirus in the family of Hepeviridae, is the major cause of several outbreaks of waterborne hepatitis in tropical and subtropical countries and of sporadic cases of viral hepatitis in endemic and industrialized countries. Transmission of HEV occurs predominantly by the fecal-oral route although parenteral and perinatal routes have been implicated. The overall death rate among young adults and pregnant women is 0.5-3% and 15-20%, respectively. HEV is a small non-enveloped particle that consists of a polyadenylated single-strand RNA molecule containing three discontinuous and partially overlapping open reading frames. There are four major genotypes of HEV and a single serotype. At present, there are approximately 1,600 sequences of HEV that are already available at INSDC of both human and animal isolates. Diagnostic and molecular assays have been described for the accurate differentiation of ongoing from remote infection of HEV. Identification and characterization of swine HEV in the United States, Japan, and many other countries and their close relationship to locally characterized human HEV found in the same geographic areas prove that HEV is indeed a zoonotic virus and that domestic swine, wild deer, and boars are reservoirs of HEV in nature. A cell culture system for the propagation of the virus has been described, and a very successful phase 2 vaccine trial has been completed. This review summarizes the current knowledge on the molecular biology, clinical features, transmission, diagnosis, epidemiology, and prevention of HEV.

Hepatitis E virus

Hepatitis E virus (HEV) is the aetiological agent of non-HAV enterically transmitted hepatitis. It is the major cause of sporadic as well as epidemic hepatitis, which is no longer confined to Asia and developing countries but has also become a concern of the developed nations. In the Indian subcontinent, it accounts for 30-60% of sporadic hepatitis. It is generally accepted that hepatitis E is mostly self-limited and never progresses to chronicity. It has a higher mortality in pregnant women where the disease condition is accentuated with the development of fulminant liver disease. Currently, no antiviral drug or vaccine is licensed for HEV, although a vaccine candidate is in clinical trials. HEV genome is 7.2kb in size with three open reading frames (ORFs) and 5' and 3' cis acting elements, which have important roles to play in HEV replication and transcription. ORF1 codes for methyl transferase, protease, helicase and replicase; ORF2 codes for the capsid protein and ORF3 for a protein of undefined function. HEV has recently been classified in the genus Hepevirus of the family Hepeviridae. There are four major recognised genotypes with a single known serotype. The absence of a reliable in vitro propagation system is an obstacle to deciphering HEV biology. The genome of HEV has been cloned, sequenced and the infectious nature of these replicons has been established. However, questions related to replication, transcription, virus-host interactions and pathogenesis remain to be answered. This comprehensive review summarises the progress made so far in HEV research, and addresses some of the unanswered questions.

Egg whites from eggs of chickens infected experimentally with avian hepatitis E virus contain infectious virus, but evidence of complete vertical transmission is lacking

Avian hepatitis E virus (HEV) is genetically and antigenically related to human HEV. Vertical transmission of HEV has been reported in humans, but not in other animals. In this study, we showed that avian HEV could be detected in chicken egg-white samples. Subsequently, avian HEV in egg white was found to be infectious, as evidenced by the appearance of viraemia, faecal virus shedding and seroconversion in chickens inoculated with avian HEV-positive egg white, but not in chickens inoculated with HEV-negative egg white. To further assess the possibility of vertical transmission of avian HEV, batches of embryonated eggs from infected hens were hatched, and hatched chicks were monitored for evidence of avian HEV infection. However, no virus was detected in samples collected from the hatched chicks throughout this study, suggesting that avian HEV could not complete the vertical transmission cycle. The possible implications of our findings are also discussed.

Congenital infections associated with international travel during pregnancy

With the overall increase in international travel, there is likely to be an increase in travel during pregnancy as well. In developing countries, pregnant women face exposures that can add significant risk for neonatal morbidity and mortality. Infections that can occur in utero or in the early neonatal period include malaria, yellow fever, tuberculosis, hepatitis, human immunodeficiency virus, leishmaniasis, toxoplasmosis, filariasis, Japanese encephalitis, rubella, typhoid fever, leptospirosis, dengue fever, Helicobacter pylori, and trypanosomiasis. When travel and potential exposure cannot be avoided, preventive measures are usually effective. Pretravel consultation should include careful discussion of length of travel, antimalarial prophylaxis, insect avoidance, food and water hygiene, vaccination, and body fluid precautions.

Hepatitis E viruses in humans and animals

Hepatitis E virus (HEV) is an emerging pathogen belonging to a newly recognized family of RNA viruses (Hepeviridae). HEV is an important enterically transmitted human pathogen with a worldwide distribution. It can cause sporadic cases as well as large epidemics of acute hepatitis. Epidemics are primarily waterborne in areas where water supplies are contaminated with HEV of human origin. There is increasing evidence, however, that many animal species are infected with an antigenically similar virus. A recently isolated swine virus is the best candidate for causing a zoonotic form of hepatitis E. The virus is serologically cross-reactive with human HEV and genetically very similar, and the human and swine strains seem to be cross-infective. Very recent evidence has also shown that swine HEV, and possibly a deer strain of HEV, can be transmitted to humans by consumption of contaminated meat. In this review, we discuss the prevalence, pathogenicity, diagnosis and control of human HEV, swine HEV, the related avian HEV and HEV in other hosts and potential reservoirs.

Liver disease in pregnancy

Liver dysfunction during pregnancy can be caused by conditions that are specific to pregnancy or by liver diseases that are not related to pregnancy itself. This review attempts to summarize the epidemiology, pathophysiology, and management of the different pregnancy-related liver diseases, and to review different liver diseases not related to pregnancy and how they may affect or be effected by pregnancy. Some of the liver diseases specific to pregnancy can cause significant morbidity and mortality both to the mother and to the fetus, while most of the liver diseases not specific to pregnancy do not have a deleterious effect on the pregnancy itself.

Hepatitis E in pregnancy

OBJECTIVES

To study the spectrum and the clinical and biochemical course of viral hepatitis E during pregnancy.

METHODS

In this prospective study, sera of 62 pregnant women having jaundice in the third trimester of pregnancy were analyzed for markers of hepatitis A, B, C and E viruses. The cord blood samples of hepatitis E virus (HEV)-positive pregnant women at the time of delivery were tested for IgM anti-HEV antibodies by enzyme-linked immunosorbent assay and HEV-RNA by reverse transcriptase polymerase chain reaction.

RESULTS

Of the 62 patients, 45.2% had HEV infection and nine developed fulminant hepatic failure (FHF). Eighty-one percent of FHF cases and 37.25% of acute viral hepatitis cases were caused by HEV. Approximately two-thirds of the pregnant women with HEV infection had preterm deliveries. The mortality rate among the HEV-positive pregnant women was 26.9%. Vertical transmission was observed in 33.3% of cases.

CONCLUSIONS

One-third of the pregnant women with HEV infection had a severe form of hepatitis in the third trimester of pregnancy, i.e. FHF. Hepatitis E in pregnancy is associated with high rates of preterm labor and mortality.

Investigation of the incidence of hepatitis E virus among pregnant women in Turkey

AIM

The aim of our study was to determine the prevalence of hepatitis E virus (HEV) among pregnant and non-pregnant women in Middle Anatolia, identify the factors that affect being HEV positive and to study the effects of HEV positivity on mother and fetus.

METHODS

The study included 245 pregnant women who applied to various health centers and 76 cases in the same age range as the control. Blood samples taken from the cases were tested in terms of anti-HEV, IgM and IgG using the microELISA method.

RESULTS

None of the blood samples tested revealed anti-HEV IgM positive, an indicator of acute infection, while 31 pregnant women (12.6%) and nine cases in the control group (11.8%) were found to have anti-HEV IgG positive (P > 0.05). It was seen that in pregnant women such factors as advanced age, lower educational and income levels and rural residence were correlated with higher anti-HEV IgG positive values (P < 0.05). HEV infection is endemic in Afyon and its vicinity. There were no statistical differences between pregnant women and non-pregnant women at similar ages in terms of HEV seropositivity.

CONCLUSION

It can be suggested that pregnancy does not constitute a predisposition to HEV infection.

Genetic characterization and sequence heterogeneity of a canadian isolate of Swine hepatitis E virus

Swine hepatitis E virus (HEV) is a newly identified potentially zoonotic agent that is possibly transmitted to humans from pigs. Swine HEV is prevalent in pig populations and does not cause abnormal clinical symptoms in infected pigs, further implicating a likelihood of a risk of transmission to humans by normal contact. To date in North America, only one strain of swine HEV (strain US swine) has been fully sequenced. In the present study, we identified a swine HEV isolate from pigs in Canada, designated the Arkell strain, and determined the full length of the genomic sequence. The genome of Canadian strain Arkell consisted of 7,242 nucleotides, excluding the poly(A) tail of at least 15 A residues. The genome contained three open reading frames (ORFs), ORF1, ORF2, and ORF3, which had coding capacities for proteins of 1,708, 660, and 122 amino acids, respectively. Comparative analysis of the full-length genomic sequence indicated that the sequence of strain Arkell was distinct from those of all other known HEV isolates by 13 to 27% and shared the highest degrees of identity with human HEV isolates US-1 and US-2, HEV isolate US swine, and the human and swine HEV isolates recently isolated in Japan. On the basis of sequence similarities and phylogenetic analyses, HEV strain Arkell was grouped into genotype 3. The sequence of the Arkell swine HEV isolate differed from those of HEV isolate US swine and HEV isolate Japan swine by 13 and 14%, respectively. To date, two isolates of swine HEV (isolates Arkell and SK3 [D. Yoo et al., Clin. Diagn. Lab. Immunol. 8:1213-1219, 2001]) have been identified in Canadian pigs, and their sequences also differ from each other by 11.8%. Our studies indicate that, as with human HEV strains, swine HEV isolates exhibit extensive genetic heterogeneity.