Very recently, an unusual clinical presentation with an altered natural history associated with hepatitis E virus (HEV) infection has emerged in high-income industrialized nations. Although HEV infection does not develop into chronicity in general, viremia can persist for long periods of time in immunocompromised solid organ, bone marrow and stem cell transplant patients. Conceivably, the atypical clinical and virological outcomes in these cases could be related to immunosuppressive chemotherapy, resulting in suboptimal HEV-specific immune responses. In the absence of travel to endemic regions, foodborne autochthonous HEV infection due to viral genotypes 3 and 4 has been implicated in the chronic cases. Presently, pegIFN-α-2a and ribavirin, the commonly used drugs to treat chronic viral hepatitis, are proving very promising in hepatitis E patients. Nevertheless, the most-awaited HEV vaccine could be protective in naïve travelers or high-risk group populations. The mechanisms of establishing chronic HEV infection and the disease severity have hitherto not been clearly understood. Therefore, a comprehensive clinical, virological and molecular study is needed to understand and control the disease.

At the annual general meeting of the Developing Countries Vaccine Manufacturers Network (DCVMN) members renewed their engagement and cooperative spirit in pursuing the mission of increasing the quality and availability of affordable vaccines for all people. Thirteen years after its establishment, DCVMN moves into the Decade of Vaccines with renewed dynamism and synergy to create greater impact and shape the global and regional vaccination landscape, while supporting national growth. The DCVMN is growing: 12 new members joined in 2012, making a total of 37 members from 14 countries; 9 of these 37 manufacturers make WHO-prequalified vaccines. More than one hundred and forty delegates from 23 countries attended the annual general meeting, representing 24 vaccine manufacturers and leaders of 20 major global health institutions. Over the course of two days, delegates exchanged information and ideas on how to jointly achieve the common goal of protecting people against known and emerging infectious diseases. In an increasingly complex environment of new technologies, demanding regulatory pathways, higher cost of production, and a growing number of legal and intellectual property issues, it is observed that many manufacturers and stakeholders are engaged in technology transfer initiatives. This well-attended meeting highlighted the growing impact and important contributions of developing country vaccine manufacturers in shaping the global vaccine landscape. The successful introduction of a first ever vaccine against hepatitis E and of a new vaccine against meningitis A, tailored for African meningitis belt countries, illustrate the innovative capacity of DCVMN members. An increase in the variety of collaborations, partnerships and alliances between DCVM and various institutions was observed. Interestingly, bilateral technology transfer partnerships between DCVMs themselves are on the rise.

Full-length sequences were determined and analyzed for two human (MO and W3) and one swine (W2-5) hepatitis E virus (HEV) isolates from Beijing, China. The genomes of the three strains were composed of 7242, 7239, 7239 nucleotides, respectively, excluding the poly (A) tails, and were 84% identical to each other. All were classified into genotype 4. Sequence analysis shows that the 2 human isolates have up to 91-94% nucleotide identity in full length genome with swine strains isolated in China, while the swine isolate share 92% identity with the human strain T1 from Beijing. At the amino acid level, the three strains share 94%, 97% and 89-92% identity in the ORF1, ORF2 and ORF3 proteins respectively. The human strains MO and W3 have the highest identity, 97%, 98%-99% and 96%-98% in ORFs 1-3, respectively, to swine strains CHN-XJ-SW13 and CHN-XJ-SW33 from Xinjiang, China, while swine strain W2-5 has highest identity with the human strain HE-JA2, 96%, 99% and 91% in ORFs 1-3, respectively. Genotype specific amino acid substitutions were found at a single site in all three ORFs by sequences alignment, and genotype specific short sequences (5-10 aa in length) were found in ORF1 and the C-terminus of ORF3. However, no difference was found at any amino acid position that discriminates between human and swine HEVs within genotype 4 for any of the three ORFs. These results indicated that the genotype 4 HEV strains from humans and pigs in China may evolve from the common ancestor.

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.

BACKGROUND:

Viral hepatitis E clinically ranges between acute self-limiting hepatitis (AVH) and acute liver failure (ALF). The varied clinical course of the disease possibly thought to be immune-mediated. High-mobility group box 1 (HMGB1) is a non-histone chromosomal nuclear protein with recently discovered pro-inflammatory and immunomodulatory action. Its presence in abundance within hepatocytes is thought provoking in patients with hepatitis.

AIM:

The present study was designed to elucidate the role of circulating HMGB1 and its gene expression in patients with viral hepatitis E.

METHODS:

Blood samples were obtained from AVH (n = 38), ALF (n = 34) and healthy controls (HC, n = 30). The HMGB1 levels were estimated in serum by quantitative-micro-ELISA. Gene expression levels were studied in the patient's PBMCs by real-time PCR. Lymphocyte proliferation was estimated by colorimetric-MTT assay.

RESULTS:

Mean circulating HMGB1 levels in HC, AVH and ALF patients were found to be 12.04 ± 2.23, 112.6 ± 13.33 and 225.3 ± 15.04 ng/ml respectively. The levels were significantly higher in ALF than AVH and HC (P < 0.0001). Moreover, 88.2% of ALF patients with >250 ng/ml of circulating HMGB1 had a fatal outcome. The gene expression of HMGB1 in the PBMCs of ALF and AVH patients were comparable. A positive correlation was observed between HMGB1 level and INR. A significantly low lymphocyte proliferation was observed in ALF patients (P = 0.008).

CONCLUSION:

Massive necrosis of hepatocytes in ALF patients might predispose to excessive accumulation of extracellular HMGB1 leading to suppression of T-cell proliferation. Therefore, it is proposed that excessive circulating HMGB1 might play an important role in immunosuppression and fulminant course of the disease following HEV infection.

Hepatitis E virus (HEV) is endemic in India and causes epidemics and sporadic cases. However, the exact transmission route for sporadic hepatitis E remains unclear. This study investigated HEV in sporadic hepatitis cases and sewage samples, as sewage is the major source of contamination of water in developing countries.Monthly sampling and testing for HEV in sewage samples from Vellore, India was carried out for 1 year (November 2009-October 2010) and plasma and/or fecal samples from sporadic hepatitis cases presenting to a hospital in Vellore during 2006-2010 were tested for HEV RNA. A total of 144 raw sewage samples and 94 samples from sporadic hepatitis cases were tested for HEV RNA using RT-PCR.The prevalence of HEV RNA in sewage and sporadic cases was 55.6% and 9.6%, respectively. HEV strains isolated from sewage showed 94-100% nucleotide sequence similarity with the HEV strains isolated from the sporadic hepatitis cases. HEV RNA in sewage was identified more often during the summer (81.2%) than the monsoon season (14.5%) (p < 0.001).This study indicates that sewage may be a source of contamination for sporadic hepatitis and also underscores the need for preventive measures to protect drinking water from sewage contamination, particularly in the summer. GENBANK ACCESSION NUMBERS: HEV strains isolated from this study were deposited in GenBank under accession numbers JF972766-JF972773, JN705651-JN705659 and JN705660-JN705662.

Hepatitis E virus (HEV) is the major cause of epidemic and sporadic hepatitis globally. Outbreaks are associated with fecal contamination of drinking water, yet the environmental reservoir of HEV between epidemics remains unclear. In contrast to neighboring countries, where epidemics and sporadic disease co-occur, HEV-endemic communities in rural Bangladesh seldom report outbreaks; sporadic hepatitis E is reported from urban and rural areas of the country. Besides typical enteric risk factors, other routes for HEV infection and disease are unclear. We conducted monthly household surveillance of a southern Bangladeshi community of 23,500 people to find incident cases of acute hepatitis E over a 22 month period. An algorithm was used to capture 279 candidate cases, of which 46 were confirmed acute HEV infections. An exploratory case-control study was conducted to identify putative risk factors for disease. Nearly 70% of cases were over 15 years old. Female gender seemed protective (OR:0.34) against hepatitis E in this conservative setting, as was the use of sanitary latrines (OR:0.28). Socioeconomic status or animal exposures were not significant predictors of disease, although outdoor employment and recent urban travel were. Unexpectedly, recent contact with a "jaundiced" patient and a history of injection exposure in the 3 months prior to disease (OR:15.50) were significant. Susceptible individuals from "endemic" communities share similar enteric exposure risks to those commonly associated with tourists from non-endemic countries. This study also raises the novel possibility of parenteral and person-to-person transmission of HEV in non-epidemic, sporadic disease settings.

SUMMARY In this study we assessed the seroprevalence of hepatitis E virus (HEV) infection in both the Italian population and immigrants from developing countries in Foggia (Apulia, Southern Italy). The seroprevalence of HEV was determined in 1217 subjects [412 (34%) immigrants and 805 Italian subjects (blood donors, general population, HIV-positive, haemodialysis patients)]. Serum samples were tested for anti-HEV and confirmed by Western blot assay; in positive patients HEV RNA and genotype were also determined. There were 8·8% of patients that were positive to anti-HEV, confirmed by Western blot. The prevalence in immigrants was 19·7%, and in Italians 3·9% (blood donors 1·3%, general population 2·7%, HIV-positive patients 2·0%, haemodialysis patients 9·6%). Anti-HEV IgM was found in 38/107 (35·5%) of the anti-HEV-positive serum samples (34 immigrants, four Italians). This study indicates a higher circulation of HEV in immigrants and Italian haemodialysis patients, whereas a low prevalence of HEV antibodies was seen in the remaining Italian population.

There is dearth of information on Hepatitis E virus (HEV) infection and its co-infection with HBV among Nigerian healthcare workers (HCWs). Hence, there is the need to determine the rate of HEV infection and its association with HBV among HCWs who are at greater risk of nosocomial infections.Sera from 88 HCWs and 44 non-HCWs healthy adults as controls were tested for the presence of antibody to HEV (anti-HEV). The HCWs were also tested for HBsAg and antibody to Hepatitis B core antigen (anti-HBc) using commercially available ELISA kits.The prevalence of anti-HEV obtained among the HCWs and controls were 43% and 94% respectively (p<0.005) while those of HBsAg and anti-HBc in HCWs were respective 13% and 56%. Overall among HCWs, the prevalence of HBV infection was 65.9%, higher than HEV infection (p<0.005) with only anti-HBc greater among the male participants (p<0.005) while co-infection of HBV with HEV was 27.3%. HEV infection was least among the Paediatricians (18%) and highest among the Surgeons (55%) while HBV infection was similar in all the different occupational groups of HCWs (44-59%) except among the Gynecologists and Obstetricians (80%).Infection with HEV is high among Nigerian HCWs but lower than the rate among non-HCWs. It is also co-infected with HBV especially among the different groups of the HCWs and could occur with the diverse clinico-serological patterns of HBV infection.

Hepatitis E virus (HEV) is a major cause of enterically transmitted acute hepatitis in developing nations and occurs in sporadic and epidemic forms. The disease may become severe with high mortality (20%) among pregnant women. Due to lack of efficient cell culture system and small animal model, early molecular events of HEV infection are not yet known. In the present study, human lung epithelial cells, A549, were infected with HEV to monitor expression levels of genes/proteins in antiviral pathways. Both live and UV inactivated virus elicited robust induction of inflammatory cytokines/chemokines such as IL-6, IL-8, TNF-α, and RANTES within 12 h of infection. Cells exposed to soluble capsid protein showed no induction suggesting the capsid structure and not the protein being detected as the pathogen pattern by cells. A delayed up-regulation of type I interferon genes only by the live virus at 48 h post HEV infection indicated the need of virus replication. However, absence of secreted interferons till 96 h suggested possible involvement of post-transcriptional regulation of type I IFN expression. HEV infected cells showed activation of both NF-κB and IRF3 transcription factors when seen at protein levels; however, reporter gene assays showed predominant expression via NF-κB promoter as compared to IRF3 promoter. Knockdown experiments done using siRNAs showed involvement of MyD88 and TRIF adaptors in generating antiviral response thus indicating role of TLR2, TLR4 and TLR3 in sensing viral molecules. MAVS knockdown surprisingly enhanced only proinflammatory cytokines and not type I IFNs. This suggested that HEV not only down-regulates RIG-I helicase like receptor mediated IFN induction but also employs MAVS in curtailing host inflammatory response. Our findings uncover an early cellular response in HEV infection and associated molecular mechanisms suggesting the potential role of inflammatory response triggered by HEV infection in host immune response and pathogenesis.