Hepatitis E

Incidence and Molecular Characterization of Hepatitis E Virus from Swine in Eastern Cape, South Africa

Hepatitis E virus-mediated infection is a serious public health concern in economically developing nations of the world. Globally, four major genotypes of HEV have been documented. Hepatitis E has been suggested to be zoonotic owing to the increase of evidence through various studies. Thus far, this paper reports on prevalence of hepatitis E virus among swine herd in selected communal and commercial farms in the Eastern Cape Province of South Africa. A total of 160 faecal samples were collected from swine herds in Amathole and Chris Hani District Municipalities of Eastern Cape Province for the presence of HEV. Of the 160 faecal samples screened, only seven were positive (4.4%) for HEV. The nucleotide sequences analyses revealed the isolates as sharing 82% to 99% identities with other strains (KX896664, KX896665, KX896666, KX896667, KX896668, KX896669, and KX896670) from different regions of the world. We conclude that HEV is present among swine in the Eastern Cape Province, albeit in low incidence, and this does have public health implications. There is a need for maintenance of high hygienic standards in order to prevent human infections through swine faecal materials and appropriate cooking of pork is highly advised.

Hepatitis E Virus and Related Viruses in Animals

Hepatitis E is an acute human liver disease in healthy individuals which may eventually become chronic. It is caused by the hepatitis E virus (HEV) and can have a zoonotic origin. Nearly 57,000 people die yearly from hepatitis E-related conditions. The disease is endemic in both developing and developed countries with distinct epidemiologic profiles. In developing countries, the disease is associated with inadequate water treatment, while in developed countries, transmission is associated with animal contact and the ingestion of raw or uncooked meat, especially liver. All human HEV are grouped into at least four genotypes, while HEV or HEV-related viruses have been identified in an increasing number of domestic and wild animal species. Despite a high genetic diversity, only one single HEV serotype has been described to date for HEV genotypes 1-4. The discovery of new HEV or HEV-related viruses leads to a continuing increase in the number of genotypes. In addition, the genome organization of all these viruses is variable with overlapping open reading frames (ORF) and differences in the location of ORF3. In spite of the role of some domestic and wild animals as reservoir, the origin of HEV and HEV-related viruses in humans and animals is still unclear. This review discusses aspects of the detection, molecular virology, zoonotic transmission and origin of HEV and HEV-related viruses in the context of 'One Health' and establishes a link between the previous and the new taxonomy of this growing virus family.

Hepatitis E virus: the current scenario

Hepatitis E infection, caused by the hepatitis E virus (HEV), is a common cause of acute hepatitis in developing countries with poor sanitation and hygiene. The virus is classified into four genotypes (1-4) with one serotype. Genotypes 1 and 2 exclusively infect humans, whereas genotypes 3 and 4 also infect other animals, particularly pigs. In endemic areas, large outbreaks of acute hepatitis caused by viruses of genotype 1 or 2 frequently occur due to fecal-oral transmission, usually through contamination of drinking water. With a high attack rate in young adults (aged 15-45 years), the disease is particularly severe among pregnant women (20-30% mortality). HEV appears to be a zoonotic disease, with transmission from pigs, wild boars, and deer, or foodborne. Chronic infections are rare, except in immunosuppressed persons, such as organ transplant recipients. A subunit vaccine has been shown to be effective in preventing the clinical disease, but is not yet commercially available. Our understanding of HEV has undergone major changes in recent years and in this article we review the currently available information with regard to the molecular biology, pathobiology, and epidemiology of HEV infection. We also review the current therapeutic interventions and strategies being used to control HEV infection, with emphasis on possible approaches that could be used to develop an effective vaccine against HEV.

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.

The ORF3 protein of hepatitis E virus interacts with liver-specific alpha1-microglobulin and its precursor alpha1-microglobulin/bikunin precursor (AMBP) and expedites their export from the hepatocyte

Hepatitis E virus (HEV), a plus-stranded RNA virus contains three open reading frames. Of these, ORF1 encodes the viral nonstructural polyprotein; ORF2 encodes the major capsid protein and ORF3 codes for a phosphoprotein of undefined function. Using the yeast two-hybrid system to screen a human cDNA liver library we have isolated, an N-terminal deleted protein, alpha(1) -microglobulin/bikunin precursor (AMBP) that specifically interacts with the ORF3 protein of HEV. Independently cloned, full-length AMBP was obtained and tested positive for interaction with ORF3 using a variety of in vivo and in vitro techniques. AMBP, a liver-specific precursor protein codes for two different unrelated proteins alpha(1)-microglobulin (alpha(1)m) and bikunin. alpha(1) m individually interacted with ORF3. The above findings were validated by COS-1 cell immunoprecipitation, His(6) pull-down experiments, and co-localization experiments followed by fluorescence resonance energy transfer analysis. Human liver cells showing co-localization of ORF3 with endogenously expressing alpha(1) m showed a distinct disappearance of the protein from the Golgi compartment, suggesting that ORF3 enhances the secretion of alpha(1)m out of the hepatocyte. Using drugs to block the secretory pathway, we showed that alpha m was not degraded in the presence of ORF3. Finally, (1)pulse labeling of alpha(1)m showed that its secretion was expedited out of the liver cell at faster rates in the presence of the ORF3 protein. Hence, ORF3 has a direct biological role in enhancing alpha(1)m export from the hepatocyte.

Hepatitis C, E, F, G, and non-A-G

Inflammation of the liver is known as hepatitis. Six or seven viruses, hepatitis viruses A through G, are responsible for most cases of viral hepatitis. In this second of a series of three articles, current knowledge regarding hepatitis C, E, F, G, and non-A-G is reviewed. Up to 80% of patients infected with hepatitis C progress to chronic liver disease. Hepatitis E is an enteric hepatitis that is endemic in Asia. Hepatitis F may be a mutant hepatitis C. Hepatitis G is a posttransfusion hepatitis. Non-A-G hepatitis consists of all of the hepatitis viruses awaiting identification. Up-to-date information regarding each of these types of hepatitis viruses is presented herein, because every phase of patient care improves when health care professionals are knowledgeable regarding the illnesses of their clients.

The unique riverine ecology of hepatitis E virus transmission in South-East Asia

The ecology of hepatitis E virus (HEV) transmission in South-East Asia was assessed from a review of 6 published and 3 unpublished NAMRU-2 reports of hepatitis outbreak investigations, cross-sectional prevalence studies, and hospital-based case-control studies. Findings from Indonesia and Viet Nam show epidemic foci centred in jungle, riverine environments. In contrast, few cases of acute, clinical hepatitis from cities in Indonesia, Viet Nam and Laos could be attributed to HEV. When communities in Indonesia were grouped into areas of low (< 40%), medium (40-60%), and high (> 60%) prevalence of anti-HEV antibodies, uses of river water for drinking and cooking, personal washing, and human excreta disposal were all significantly associated with high prevalence of infection. Conversely, boiling of river drinking water was negatively associated with higher prevalence (P < 0.01). The protective value of boiling river water was also shown in sporadic HEV transmission in Indonesia and in epidemic and sporadic spread in Viet Nam. Evidence from Indonesia indicated that the decreased dilution of HEV in river water due to unusually dry weather contributed to risk of epidemic HEV transmission. But river flooding conditions and contamination added to the risk of HEV infection in Viet Nam. These findings attest to a unique combination of ecological and environmental conditions predisposing to epidemic HEV spread in South-East Asia.

Changes in immune activation markers during pregnancy and postpartum

Changes in CD4 + cell levels and other immune parameters have been reported to occur during pregnancy but the timing of these alterations and their relationship to changes in immune function have not been well characterized. In addition, the influence of sociodemographic, obstetric, and other covariates on these relationships is largely unknown. We measured three immune activation markers, soluble interleukin-2 receptor (sIL-2Ralpha), soluble CD8 antigen (sCD8), and neopterin during pregnancy and postpartum in 170 HIV-1-seronegative women enrolled in the Mothers and Infants Cohort Study. Ante-partum and postpartum changes in these markers were examined using multivariable longitudinal random effects models. Neopterin levels began to rise well before delivery and were in decline by 2 months postpartum. sIL-2Ralpha and sCD8 levels increased at or near delivery and peaked by 2 months postpartum. After adjustment for other variables, the peak in sIL-2Ralpha was greater among women with pre-term than full-term deliveries (P = 0.05). All three markers were higher in whites than non-whites and in 'hard' drug users than non-users (P < or = 0.001 for each). After adjustment for these and other variables, hepatitis C virus (HCV) seropositivity was associated with higher levels of sCD8 and neopterin (P < or = 0.001 for each) but not sIL-2Ralpha (P = 0.27). These longitudinal data indicate that a state of broad immune activation develops at or near delivery. A number of maternal variables appear to influence the magnitude of these changes.