Viral hepatitis: global goals for vaccination

World Hepatitis day 2021 -screening and vaccination against Hepatitis B virus in Accra, Ghana

BACKGROUND

In Ghana, Hepatitis B virus (HBV) infection remains a major public health threat as in many parts of the world. Even with an effective vaccine, there are shortfalls with low vaccine coverage among adults. To create awareness and encourage vaccination, community engagement and public-private partnerships are needed in endemic settings to help fund campaigns and offer screening and vaccinations at no cost to under privileged people.

OBJECTIVES

An awareness and screening exercise was scheduled by University of Ghana-based Hepatitis-Malaria (HEPMAL) project team to coincide with the World Hepatitis Day (WHD) 2021. It was to engage the community in creating awareness of the menace and offer diagnostic services to ascertain prevalence levels and provide needed clinical support.

METHODS

Participants from the University of Ghana community and its immediate environs were registered, taken through pre-counselling sessions where they were educated on hepatitis transmission and prevention before consenting. Eligible participants were screened for HBV markers (HBsAg, HBeAg, HBsAb, HBcAb,HbcAg) with a rapid test kit. All HBsAb-negative participants were recommended for initial vaccination at the event, whilst the subsequent shots were administered at the University Hospital Public Health Department. Hepatitis B surface Antigen-positive participants were counselled and referred for appropriate care.

RESULTS

/ Outcomes: A total of 297 people, comprising of 126 (42%) males and 171 (58%) females aged between 17 and 67 years were screened during the exercise. Amongst these, 246 (82.8%) showed no detectable protective antibodies against HBV and all of them agreed to and were given the first dose HBV vaccine. Additionally, 19 (6.4%) individuals tested positive for HBsAg and were counselled and referred to specialists from the University Hospital for further assessment and management. We found that 59 (19.9%) of our participants had previously initiated HBV vaccination and had taken at least one dose of the vaccine more than 6 months prior to this screening, 3 of whom tested positive for HBsAg. For the three-dose HBV vaccines deployed, a little over 20% (50/246) and a further 17% (33/196) did not return for the second and the third doses respectively, resulting in an overall 66% (163/246) of persons who completed all three vaccinations.

CONCLUSIONS

/ Lessons learnt: Our medical campaign exercise established an active case prevalence rate of 6.4% and achieved a full vaccination success rate of 66% which is critical in the induction of long-term immunity in the participants. Aside these achievements, we would like to reiterate the importance of the use of different approaches including educational events and WHD activities to target groups and communities to raise awareness. Additionally, home and school vaccination programmes may be adopted to enhance vaccine uptake and adherence to the vaccination schedule. We plan to extend this screening exercise to deprived and/or rural communities where HBV incidence may be higher than in urban communities.

Presence of Intact Hepatitis B Virions in Exosomes

BACKGROUND & AIMS

Hepatitis B virus (HBV) was identified as an enveloped DNA virus with a diameter of 42 nm. Multivesicular bodies play a central role in HBV egress and exosome biogenesis. In light of this, it was studied whether intact virions wrapped in exosomes are released by HBV-producing cells.

METHODS

Robust methods for efficient separation of exosomes from virions were established. Exosomes were subjected to limited detergent treatment for release of viral particles. Electron microscopy of immunogold labeled ultrathin sections of purified exosomes was performed for characterization of exosomal HBV. Exosome formation/release was affected by inhibitors or Crispr/Cas-mediated gene silencing. Infectivity/uptake of exosomal HBV was investigated in susceptible and non-susceptible cells.

RESULTS

Exosomes could be isolated from supernatants of HBV-producing cells, which are characterized by the presence of exosomal and HBV markers. These exosomal fractions could be separated from the fractions containing free virions. Limited detergent treatment of exosomes causes stepwise release of intact HBV virions and naked capsids. Inhibition of exosome morphogenesis impairs the release of exosome-wrapped HBV. Electron microscopy confirmed the presence of intact virions in exosomes. Moreover, the presence of large hepatitis B virus surface antigen on the surface of exosomes derived from HBV expressing cells was observed, which conferred exosome-encapsulated HBV initiating infection in susceptible cells in a , large hepatitis B virus surface antigen/Na⁺-taurocholate co-transporting polypeptide-dependent manner. The uptake of exosomal HBV with low efficiency was also observed in non-permissive cells.

CONCLUSION

These data indicate that a fraction of intact HBV virions can be released as exosomes. This reveals a so far not described release pathway for HBV.

Hepatit B Yüzey Antijeni (HBsAg) Pozitif Hastalarda Hepatit A ve Hepatit E Virüsü Seropozitifliği

Introduction: In this study, we aimed to determine the anti-HAV IgG and anti-HEV IgG seroprevalence in patients admitted to our clinic with Hepatitis B surface antigen (HBsAg) positivity. Material and Method: Data of 1827 patients followed up on for HBsAg positivity between 2010 and 2019 were obtained retrospectively. Results: The mean age of 1827 HBsAg positive patients was 42.71±14.84; there were 730 (39.96%) female patients and 1097 (60.04%)male. Of the 923 HBsAg positive patients whose anti-HAV IgG was measured, 830(%89,9) were detected to be positive, and 93 (10.1%) negative. Anti-HAV IgG negative patients were most often in the 21-30 age range (38.7%). Age medians were significantly different between the groups (p=0.001). HBsAg positive patients who were also positive for anti-HAV IgG tended to be older than anti-HAV IgG negative patients. In contrast, there was no significant difference in gender between anti-HAV IgG negative and positive patients (p=0.674). Of 143 HBsAg positive patients who were tested for anti-HEV-IgG, five were positive (3.5%). Conclusion: It is of interest that we found a lower rate of anti-HAV IgG positivity in young Chronic Hepatitis B patients. When hepatitis B virus is detected, a test for anti-HAV IgG should be requested from patients and if the test result is negative, the patient should be vaccinated. Our study data analysis also revealed a low anti-HEV IgG positivity.

Undiagnosed Seroprevalence of Hepatitis B and C Virus Infections in the Community of Wolaita Zone, Southern Ethiopia

Background

Despite Ethiopia’s hepatitis endemic status with intermediate to hyperendemic level, there is no national strategy for monitoring, preventing, and controlling viral hepatitis. In order to advise community-based intervention programs, studies on the magnitude, determinant factors, and understanding of indigenous social organization are important. Thus, this study examined undiagnosed seroprevalence and associated factors for HBV and HCV infections among community members in Wolaita Zone, Southern Ethiopia.

Methods

A cross-sectional study was conducted on 320 individuals from randomly selected two woredas in the Wolaita Zone to determine the magnitude of HBV and HCV. Multistage sampling was used to select participants. Relevant clinical and sociodemographic data were collected using a structured questionnaire. One test strip technique was used for the screening of hepatitis B surface antigen and for antibodies against HCV. Both tests were confirmed by ELISA methods. The associated factors were assessed using bivariate and multivariate logistic regression analyses. P-values less than 0.05 were considered statistically significant.

Results

The seroprevalence for HBV infection was 6.6% (95% CI: 4.22%, 8.69%) using a one-step HBsAg test strip and 5.6% (95% CI: 3.47%, 8.58%) using confirmatory test (ELISA). The two tests had a very good agreement (K = 0.918; SE = 0.047; P < 0.001). The overall seroprevalence for HCV infection was 1.9% (95% CI: 0.9%, 3.0%). All four of the one-step HCV test strip positives were also positive by ELISA. One (0.3%) of the participants was co-infected with HBV and HCV. Hospital admission (AOR = 0.22; 95% CI = 0.5–0.95) and needle stick (AOR = 0.15; 95% CI = 0.07–0.72) were independently associated with HBV infections.

Conclusion

According to the current study, in Wolaita community, there is endemic to HBV at a higher-intermediate level and to HCV at a low level. It would be imperative to increase awareness of transmission modes and prevention of infection, as well as vaccination, in order to reduce the burden of both HBV and HCV.

Changing epidemiology of liver disease in Asia: Dual infection of HBV and HCV

Transmission of hepatitis B virus (HBV) and hepatitis C virus (HCV) is similar regarding the mode of transmission and related risk factors. Therefore, it is not rare to encounter dual HBV/HCV infection in populations at risk of parenteral exposure to hepatitis viruses. Besides, in HBV endemic countries before the era of global HBV vaccination, dual HBV/HCV infection was clinically significant likely because of HCV superinfection over pre-existing HBsAg carriage. Universal childhood HBV vaccination was implemented worldwide since 1992. Public education programs for prevention of new hepatitis viral infections have been actively promoted recently by World Health Organization. Apart from preventive measures, potent anti-HBV agents effective in the control of viral replication have been introduced gradually in the past three decades. Direct acting antiviral agents capable of curing HCV infection in more than 97% of patients with chronic hepatitis C have also been widely implemented in the past decade. These interventions will change the epidemiology of new HBV or HCV mono-infection and dual HBV/HCV infection. Understanding the evolution in the epidemiology of dual HBV/HCV infection is important for evaluation of current public health policy towards infectious disease control in different countries. The changing prevalence of dual HBV/HCV infection in certain Asia-Pacific countries will be re-visited based on endemicity of HBV or HCV, as well as in populations at risk of parenteral viral infection.

Effectiveness of hepatitis B vaccination in chronic HCV patients after successful generic direct acting antiviral therapy: significance of isolated hepatitis B core antibodies

OBJECTIVE

Previous reports show conflicting results regarding hepatitis B virus (HBV) vaccine efficacy in Hepatitis C virus (HCV) infected individuals and in those with isolated hepatitis B core antibodies (HBcAb). We aimed to evaluate the effectiveness of HBV vaccine and identify possible factors that may contribute to hyporesponsivness in HCV-treated patients, including those with isolated HBcAb.

METHODS

We conducted a prospective study with 118 enrolled chronic HCV patients who followed a 12-week regimen of direct acting antivirals (DAAs) and were evaluated for HBV serological markers. Eventually, 98 received appropriate HBV vaccination and were assessed for response.

RESULTS

A total of 57.1% were vaccine responders although only 5.1% achieved a seroprotective level of HBsAb titre. The response rate was significantly lower among treated HCV patients with isolated HBcAb [2 (5.6%) vs. 40 (64.5%) respectively]. On multivariate analysis, advanced age [OR (95% CI) = 1.09 (1.02-1.17)] and presence of isolated HbcAb [OR (95% CI) = 39.59 (7.98-196.63)] were predictors of vaccine non-response. In our cost-effectiveness models, the cost of HBV serological screening was less than the nationally adopted non-screening approach. A model ratifying reinforced vaccination in non-responder HBcAb seropositive HCV patients would incur extra cost.

CONCLUSION

Hyporesponsiveness to the HBV vaccination is frequent in chronic HCV patients even after achieving SVR following DAAs. Although there is no consensus on the clinical management of patients with isolated HBcAb, our cost-effectiveness options may support decision-making for better clinical benefit and proper health investments.

Lessons from intensified surveillance of viral hepatitis A, Israel, 2017 and 2018

Introduction

Universal vaccination of toddlers has led to very low hepatitis A (HAV) endemicity in Israel. However, sporadic outbreaks still occur, necessitating better surveillance.

Aim

To implement a comprehensive HAV surveillance programme.

Methods

In 2017 and 2018, sera from suspected HAV cases that tested positive for anti-HAV IgM antibodies were transferred to the Central Virology Laboratory (CVL) for molecular confirmation and genotyping. Sewage samples were collected in Israel and Palestine* and were molecularly analysed. All molecular (CVL), epidemiological (District Health Offices and Epidemiological Division) and clinical (treating physicians) data were combined and concordantly assessed.

Results

Overall, 146 cases (78 in 2017 and 68 in 2018, median age 34 years, 102 male) and 240 sewage samples were studied. Most cases (96%) were unvaccinated. In 2017, 89% of cases were male, 45% of whom were men who have sex with men (MSM). In 2018, 49% were male, but only 3% of them were MSM (p < 0.01). In 2017, 82% of cases and 63% of sewage samples were genotype 1A, phylogenetically associated with a global MSM-HAV outbreak. In 2018, 80% of cases and 71% of sewage samples were genotype 1B, related to the endemic strain previously identified in Israel and Palestine*. Environmental analysis revealed clustering of sewage and cases’ sequences, and country-wide circulation of HAV.

Conclusions

Molecular confirmation of HAV infection in cases and analysis of environmental samples, combined with clinical and epidemiological investigation, may improve HAV surveillance. Sequence-based typing of both clinical and sewage-derived samples could assist in understanding viral circulation.

Administering an additional hepatitis B vaccination dose after 18 years maintains adequate long-term protection levels in healthcare workers

Background: HBV (hepatitis B virus) vaccination in first year of life is recommended to prevent infection. Observational studies have suggested that vaccination at birth provides protection for 90% of the population for 30 years. Data on response to booster doses and long-term protection are lacking.Methods: We compared HBV antibody levels of healthcare students who were immunized for HBV with a primary series during their first year of life (primary) to students who were immunized with a primary series and received an additional dose at age 18 (boosted) four years earlier. Antibody titres ≥10 mIU/mL were considered adequate. Those that were inadequate received another dose and were reassessed.Results: We assessed 381 students, 80.1% were primary and 19.9% boosted. A significantly higher percentage of students in the boosted group had antibody titre levels ≥10 mIU/mL compared to primary group (88.1% vs. 41.3%, p < .001). Of 179 students in the primary group with inadequate antibody levels, 134 received a booster dose and 126 of them (94%) developed anti-HBs levels ≥10 mIU/mL. Of 9 students with inadequate levels in the boosted group, 8 received another booster dose and all developed adequate levels.Conclusions: Primary vaccination against HBV at birth does not necessarily provide lifelong adequate antibody levels. Boosting at 18 years reinforces antibody levels for at least four more years. Current guidelines recommend testing and boosting all medical personal. Based on our study, it may be prudent to extend this practice to all individuals who are at higher risk.

The 2017 M Balasegaram Memorial Lecture: The Changing Landscape of Liver Diseases in Malaysia-60 Years On!

The landscape of liver diseases in Malaysia has changed dramatically since the time of Professor Balasegaram Manickavasagar—an eminent surgeon in the 1960s.

The most significant discoveries in hepatology have been that of hepatitis B virus in 1963 and hepatitis C virus in 1989, which have both been shown to be predominantly blood borne diseases.

Hepatitis B and C infections result in long term carrier state and a high propensity to develop liver cirrhosis and cancer. Hepatitis B is the most common cause of liver cirrhosis and cancer in Malaysia. Blood bank screening and public health preventive measures have reduced the disease burden significantly and an effective vaccination for hepatitis B is now incorporated in our National Immunisation Programme. Although no vaccine is available for hepatitis C, highly effective eradication therapies were introduced in 2011. These agents will significantly change the disease scenario across the world.

A “new” disease was described in 1980, by Ludwig et al.—non-alcoholic fatty liver (NAFLD) disease. With the global epidemic of obesity and diabetes mellitus, NAFLD is set to increase exponentially across the world including in Malaysia. It will be the most important liver disease in the future, replacing hepatitis B and C infections.

Comparative Molecular Field Analysis and Molecular Docking Studies on Quinolinone Derivatives Indicate Potential Hepatitis C Virus Inhibitors

Presently, there are no effective vaccines and anti-virals for the prevention and treatment of Hepatitis C virus infections and hence there is an urgent need to develop potent HCV inhibitors. In this study, we have carried out molecular docking, molecular dynamics and 3D-QSAR on heteroaryl 3-(1,1-dioxo-2H-(1,2,4)-benzothiadizin-3-yl)-4-hydroxy-2(1H)-quinolinone series using NS5B protein. Total of 41 quinolinone derivatives is used for molecular modeling study. The binding conformation and hydrogen bond interaction of the docked complexes were analyzed to model the inhibitors. We identified the molecule XXXV that had a higher affinity with NS5B. The molecular dynamics study confirmed the stability of the compound XXXV-NS5B complex. The developed CoMFA descriptors parameters, which were calculated using a test set of 13 compounds, were statistically significant. Our results will provide useful insights and lead to design potent anti-Hepatitis C virus molecules.

The changing epidemiology of liver diseases in the Asia-Pacific region

This Review presents current epidemiological trends of the most common liver diseases in Asia-Pacific countries. Hepatitis B virus (HBV) remains the primary cause of cirrhosis; despite declining prevalence in most Asian nations, this virus still poses a severe threat in some territories and regions. Mortality resulting from HBV infection is declining as a result of preventive measures and antiviral treatments. The epidemiological transition of hepatitis C virus (HCV) infection has varied in the region in the past few decades, but the medical burden of infection and the prevalence of its related cancers are increasing. The lack of licensed HCV vaccines highlights the need for novel treatment strategies. The prevalence of nonalcoholic fatty liver disease (NAFLD) has risen in the past decade, mostly owing to increasingly urbanized lifestyles and dietary changes. Alternative herbal medicine and dietary supplements are major causes of drug-induced liver injury (DILI) in some countries. Complications arising from these chronic liver diseases, including cirrhosis and liver cancer, are therefore emerging threats in the Asia-Pacific region. Key strategies to control these liver diseases include monitoring of at-risk populations, implementation of national guidelines and increasing public and physician awareness, in concert with improving access to health care.

Vaccination Coverage and Awareness of Hepatitis B Virus Among Healthcare Students at a University in Cyprus

Introduction

The risk for healthcare students to get infected by transmitting infectious viruses, including hepatitis B virus (HBV), in a hospital setting is extremely high through exposure to blood and/or body secretions.

Aim

The aim of this work was to evaluate both the vaccination history of healthcare students at a University in Cyprus and their serologic immunity against HBV. In addition, we assessed their knowledge and behaviors towards the transmission and prevention of hepatitis B (HB).

Results

Total amount of 168 students participated in this study and more than 50% of them provided complete documentation of vaccination history against HBV. Antibodies levels ×10 mIU/mL to HB surface antigen (HBsAg) were detected for the 98.8% of healthcare students while 1.2% of the participants tested positive for HBsAg and antibodies to HB core antigen indicating chronic infection. Our study also revealed significant gaps in the knowledge of healthcare students on the efficiency of the vaccine against HBV and in terms of the HBV transmission.

Conclusions

More information needs to be provided to healthcare students in Cyprus regarding HBV transmission and vaccination. In addition, there is a need for intervention to provide a safer workplace environment.

Positive Rate of Different Hepatitis B Virus Serological Markers in Peking Union Medical College Hospital, a General Tertiary Hospital in Beijing

Objective s To investigate the positive rate of different hepatitis B virus (HBV) serological markers, and the demographic factors related to HBV infection.Methods We enrolled all patients tested for HBV serological markers, such as HBV surface antigen (HBsAg), HBV surface antibody (HBsAb), hepatitis B e antigen (HBeAg), hepatitis B e antibody (HBeAb), HBV core antibody (HBcAb), and HBV-DNA from July 2008 to July 2009 in Peking Union Medical College Hospital. The positive rate of each HBV serological marker was calculated according to gender, age, and de- partment, respectively. The positive rates of HBV-DNA among patients with positive HBsAg were also analyzed.Results Among 27 409 samples included, 2681 (9.8%) were HBsAg positive. When patients were divided into 9 age groups, the age-specific positive rate of HBsAg was 1.2%, 9.6%, 12.3%, 10.9%, 10.3%, 9.7%, 8.0%, 5.8%, and 4.3%, respectively. The positive rate of HBsAg in non-surgical department, surgical department, and health examination center was 16.2%,5.8%,and 4.7%, respectively. The positive rate of HBsAg of males (13.3%) was higher than that of females (7.3%, P=0.000). Among the 2681 HBsAg (+) patients, 1230 (45.9%) had HBV-DNA test, of whom 564 (45.9%) were positive. Patients with HBsAg (+), HBeAg (+), and HBcAg (+) result usually had high positive rate of HBV-DNA Results (71.8%, P=0.000).Conclusions Among this group of patients in our hospital, the positive rate of HBsAg was relatively high. Age group of 20-29, males, and patients in non-surgical departments were factors associated with high positive rate of HBsAg.

Vaccine uptake and immune responses to HBV infection amongst vaccinated and non-vaccinated healthcare workers, household and sexual contacts to chronically infected HBV individuals in the South West Region of Cameroon

Background

HBV infection affects about 257 million people globally and Sub-Saharan Africa has the highest burden. The disease still constitutes a major public health problem despite the advent of preventive measures like the HBV vaccine. This study was aimed at identifying factors that influence vaccine uptake and the efficacy of administered vaccines among people at high risk of HBV infection.

Methods

This was a cross-sectional study conducted between January 2016 and December 2017. A pretested semi-structured questionnaire was used to capture information on sociodemographic and vaccination status from healthcare workers, household and sexual contacts to HBV infected people. HBV serological panel as well as quantitative anti-HBs ELISA test was done for all participants. Additional information was obtained from the institutions that administered the vaccines.

Results

A total of 265 participants with a mean age of 32.1±8.7 were enrolled. Eighty (30.2%) of them had received at least 1 dose of the HBV vaccine while 185 (69.8%) were unvaccinated. Healthcare workers were the most vaccinated (37%). Ignorance, negligence, fear of injection and the cost of the vaccine all contributed to poor vaccine uptake in the study population. Natural immunity was seen in 9 (3.4%) of the participants. Only 64.9% of the vaccinated participants attained the desirable level of anti-HBs (≥10mIU/ml) 1–2 months after ≥ 3 doses of the vaccine. Age, gender, obesity, alcohol and smoking were not significantly associated with poor immune responses. No standardized protocol was followed by the institutions administering the vaccine.

Conclusion

This study revealed very poor vaccine uptake and poor immune responses to the HBV vaccine in the study population and this should urge the health sector in Cameroon to intensify their sensitization on HBV vaccine, standardize the protocol for storing and administering the vaccine, subsidize the cost of the vaccine especially amongst healthcare workers and encourage anti-HBs post vaccination testing.

Ongoing hepatitis A among men who have sex with men (MSM) linked to outbreaks in Europe in Tel Aviv area, Israel, December 2016 - June 2017

Between December 2016 and June 2017, 19 Hepatitis A virus (HAV)-positive cases, 17 of which were among men who have sex with men (MSM) were identified in the Tel Aviv area. Seven of the 15 sewage samples collected between January and June 2017 were also HAV-positive. All sequences clustered with two of the three strains identified in the current European HAV outbreak. We demonstrate that despite an efficient vaccination programme, HAV can still be transmitted to an unvaccinated high-risk population.

Epidemiological and molecular analysis of hepatitis B virus infection in manicurists in Central Brazil

The aim of this study was to investigate the serological and molecular prevalence of hepatitis B virus (HBV) infection in 514 manicurists/pedicurists and identify the risk factors related with this infection. Samples were tested for HBV serological markers, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) by enzyme-linked immunosorbent assay (ELISA). Anti-HBc-positive samples were tested to investigate occult hepatitis B by PCR. HBsAg-positive samples were genotyped and the viral loads of HBV-DNA positive samples were quantified. The overall HBV prevalence was 5.6% (29/514) and of HBsAg was 0.4% (2/514). One case of occult hepatitis B was found. The genotypes A1 and F2 were identified in two HBsAg-positive samples. Low level of education, not being born in the State of Mato Grosso do Sul and working in the central region of the city were associated with the HBV infection. No single manicurist/pedicurist was infected by HCV or HIV. These findings suggest that despite the exposure to blood contact, this occupation was not associated to an increased risk of acquiring HBV, HCV, and HIV infections.

Chronic Hepatitis B, C, and D

Chronic hepatitis B, C, and D virus infections contribute significantly to the morbidity and mortality of immunocompromised individuals. To contextualize discussion of these infections in immunocompromised patients, this paper provides an overview of aspects of infection in normal hosts. It then describes differences in disease, diagnostic testing, and therapeutic management observed in immunocompromised patients.

Taking a Stab at Cancer; Oncolytic Virus-Mediated Anti-Cancer Vaccination Strategies

Vaccines have classically been used for disease prevention. Modern clinical vaccines are continuously being developed for both traditional use as well as for new applications. Typically thought of in terms of infectious disease control, vaccination approaches can alternatively be adapted as a cancer therapy. Vaccines targeting cancer antigens can be used to induce anti-tumour immunity and have demonstrated therapeutic efficacy both pre-clinically and clinically. Various approaches now exist and further establish the tremendous potential and adaptability of anti-cancer vaccination. Classical strategies include ex vivo-loaded immune cells, RNA- or DNA-based vaccines and tumour cell lysates. Recent oncolytic virus development has resulted in a surge of novel viruses engineered to induce powerful tumour-specific immune responses. In addition to their use as cancer vaccines, oncolytic viruses have the added benefit of being directly cytolytic to cancer cells and thus promote antigen recognition within a highly immune-stimulating tumour microenvironment. While oncolytic viruses are perfectly equipped for efficient immunization, this complicates their use upon previous exposure. Indeed, the host's anti-viral counter-attacks often impair multiple-dosing regimens. In this review we will focus on the use of oncolytic viruses for anti-tumour vaccination. We will explore different strategies as well as ways to circumvent some of their limitations.

Diagnostic performance of serological assays for anti-HBs testing: Results from a quality assessment program

BACKGROUND

Post-vaccination testing after hepatitis B vaccination is indispensable to evaluate long-term immunological protection. Using a threshold level of antibodies against hepatitis B surface antigen (anti-HBs) to define serological protection, implies reproducible and valid measurements of different diagnostic assays.

OBJECTIVES

In this study we assess the performance of currently used anti-HBs assays.

STUDY DESIGN

In 2013, 45 laboratories participated in an external quality assessment program using pooled anti-HBs serum samples around the cutoff values 10IU/l and 100IU/l. Laboratories used either Axsym (Abbott Laboratories), Architect (Abbott Laboratories), Access (Beckman-Coulter), ADVIA Centaur anti-HBs2 (Siemens Healthcare Diagnostics), Elecsys, Modular or Cobas (Roche Diagnostics) or Vidas Total Quick (Biomerieux) for anti-HBs titre quantification. We analysed covariance using mixed-model repeated measures. To assess sensitivity/specificity and agreement, a true positive or true negative result was defined as an anti-HBs titre respectively above or below the cutoff value by ≥4 of 6 assays.

RESULTS

Different anti-HBs assays were associated with statistically significant (P<0.05) differences in anti-HBs titres in all dilutions. Sensitivity and specificity ranged respectively from 64%-100% and 95%-100%. Agreement between assays around an anti-HBs titre cutoff value of 10IU/l ranged from 93%-100% and was 44% for a cutoff value of 100IU/l.

CONCLUSIONS

Around a cutoff value of 10IU/l use of the Access assay may result in false-negative results. Concerning the cutoff value of 100IU/l, a sample being classified below or above this cutoff relied heavily on the specific assay used, with both the Architect and the Access resulting in false-negative results.

Potential role of killer immunoglobulin receptor genes among individuals vaccinated against hepatitis B virus in Lebanon

AIM

To explore the role of killer immunoglobulin receptor (KIR) genes in responsiveness or non-responsiveness to vaccination against hepatitis B virus.

METHODS

We recruited 101 voluntary participants between March 2010 and December 2011. Sera samples from vaccinated and non-vaccinated participants were tested for the presence of anti-HBs antibodies as a measure of protection against hepatitis B, hepatitis B surface antigen and hepatitis B core antibody as indicators of infection by enzyme-linked immunosorbent assay. KIR gene frequencies were determined by polymerase chain reaction.

RESULTS

Sera samples from 99 participants were tested for the levels of anti-HBs as an indicator of protection (≥ 10 mIU/mL) following vaccination as defined by the World Health Organization international reference standard. Among the vaccinated participants, 47% (35/74) had anti-HBs titers above 100 mIU/mL, 22% (16/74) had anti-HBs ranging between 10-100 mIU/mL, and 20% (15/74) had values of less than 10 mIU/mL. We report the lack of significant association between the number of vaccine dosages and the titer of antibodies among our vaccinated participants. The inhibitory KIR2DL1, KIR2DL4, KIR3DL1, KIR3DL2, and KIR3DL were detected in more than 95%, whereas KIR2DL2, KIR2DL3, KIR2DL5 (KR2DL5A and KIR2DL5B) were expressed in 56%, 84% and 42% (25% and 29%) of participants, respectively. The observed frequency of the activating KIR genes ranged between 35% and 55% except for KIR2DS4, detected in 95% of the study participants (40.6% 2DS4*001/002; 82.2% 2DS4*003/007). KIR2DP1 pseudogene was detected in 99% of our participants, whereas KIR3DP*001/02/04 and KIR3DP1*003 had frequencies of 17% and 100%, respectively. No association between the frequency of KIR genes and anti-HBs antibodies was detected. When we compared the frequency of KIR genes between vaccinated individuals with protective antibodies titers and those who lost their protective antibody levels, we did not detect a significant difference. KIR2DL5B was significantly different among different groups of vaccinated participants (group I > 100 mIU/mL, group II 10-100 mIU/mL, group III < 10 mIU/mL and group IV with undetectable levels of protective antibodies).

CONCLUSION

To our knowledge, this is the first study screening for the possible role of KIR genes among individuals vaccinated against hepatitis B virus (HBV). Our results can be used to design larger studies to better understand the role of KIR genes in protection against or susceptibility to HBV post vaccination.

Prevalence of hepatitis B and C markers in a population of an urban university in Rio de Janeiro, Brazil: a cross-sectional study

BACKGROUND AND RATIONALE

Epidemics of hepatitis B and C are a public health burden, and their prevalence in Brazil varies among regions. We determined the prevalence of hepatitis markers in an urban university population in order to support the development of a comprehensive program for HBV immunization and HBV/HCV diagnosis. Students, employees, and visitors (n = 2,936, 31 years IQR 24.5-50, female = 69.0% and 81.1% with at least 12 years of education) were enrolled from May to November 2013. Antibodies against hepatitis B surface antigen (anti-HBs), against hepatitis B core antigen (anti-HBc), and hepatitis B surface antigen (HBsAg) were detected with enzyme immunoassays and anti-hepatitis C virus (anti-HCV) antibodies with a chemiluminescence immunoassay. The results were confirmed with polymerase chain reaction for HCV and nucleic acid amplification test for hepatitis B virus (HBV).

RESULTS

The overall prevalence of markers among the participants was 0.136% (95% confidence interval [CI]: 0.003-0.270) for HBsAg, 6.44% (95% CI: 5.55-7.33%) for anti-HBc, 50.8% (95% CI: 48.9-52.7%) for anti-HBs > 10 mIU/mL, and 0.44% (95% CI: 0.20-0.68) for anti-HCV. Almost 30.4% had anti-HBs titers > 100 mIU/mL. Participants with a detectable HCV viral load (n = 9) were infected with genotype 1a.

CONCLUSIONS

In an urban university population, in which 80% of participants had > 11 years of education, prevalence increased with age, and self-declared ethnicity for anti-HBc and with age, marital status and professional activity for anti-HCV antibodies. A periodical offer of HCV rapid testing should be implemented, and HBsAg rapid testing should be offered to individuals above 20 years of age.

Anti-HBc Screening of Blood Donors in Bangladesh: Relevance to Containment of HBV Propagation

OBJECTIVES

To avoid further transmission of hepatitis B virus (HBV) infection, blood is tested for hepatitis B surface antigen (HBsAg) before transfusion. However, post-transfusion hepatitis B has been detected in clinics after transfusion of HBsAg-negative blood. The study presented here was undertaken to assess if HBsAg-negative blood is free from HBV or not.

METHODS

Sera were collected from 398 blood donors who were negative for HBsAg. Out of 398 blood samples, antibody to hepatitis B core antigen (ant-HBc) was detected in 82 sera samples. HBV DNA was evaluated in HBsAg-negative, anti-HBc-positive sera. HBsAg, hepatitis B e antigen (HBeAg), antibody to HBeAg (anti-HBe), and anti-HBc in the sera were measured by an enzyme-linked immunosorbent assay (ELISA). HBV DNA was quantified by a real time polymerase chain reaction (PCR).

RESULTS

Out of 82 HBsAg-negative, anti-HBc-positive sera samples, HBV DNA were detected in the sera of 7 voluntary blood donors. Out of these 7 subjects, all were negative for HBeAg. The levels of ALT were more than 30 IU/L in 6 of 7 HBVDNA-positive subjects and it was above upper limit of normal (>42 IU/ml) in one subject.

CONCLUSIONS

The present recommendation about blood transfusion of HBsAg-negative blood system is not capable of blocking HBV transmission to blood recipients. Although advanced countries have adopted nucleic acid testing (NAT) for preventing HBV transmission, developing countries may apply anti-HBc testing and ALT estimation before blood transmission.

FAS and FAS-Ligand Promoter Polymorphisms in Hepatitis B Virus Infection

BACKGROUND

The FAS and FAS-Ligand (FASL) system is an important apoptosis pathway in the liver. The FAS-mediated pathway functions by binding the FASL on the activated cytotoxic T lymphocytes and Natural Killer (NK) cells to the FAS receptor on infected hepatocytes. FAS and FASL polymorphisms, which are related to apoptosis, might influence the outcome of Hepatitis B Virus (HBV) infection.

OBJECTIVES

Thus, the present study aimed to determine if FAS and FASL promoter polymorphisms are associated with the clinical outcome of HBV infection.

PATIENTS AND METHODS

DNA samples were obtained from the infected individuals including chronic carrier (n = 50), chronic hepatitis (n = 50), cirrhosis (n = 25), naturally recovered (n = 26) and compared with those of their matched healthy controls (n = 100). Genotyping for polymorphisms of FAS-670 A/G and -1377 G/A, and FASL -844 C/T was performed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays.

RESULTS

Multiple analyses for genetic association of FAS and FASL polymorphisms were not statistically different between HBV patients (n = 125) and healthy controls (n = 100). However, genotype and allele frequencies of FASL-844 C/T were significantly different between recovered individuals and patients with cirrhosis (P = 0.02 and P=0.01, respectively). Whereas, FAS-670A/G and -1377G/A polymorphisms were similarly distributed in these two groups (P = 0.8 and P = 0.47, respectively).

CONCLUSIONS

The current study results showed that bearing -844T allele in FASL promoter region has a protective effect on cirrhosis and is involved in recovery from infection. In conclusion, it is proposed that HBV infection outcome might be influenced by FASL-844C/T polymorphism through alteration in apoptosis of hepatocytes.

Effectiveness of hepatitis B virus vaccination program in Egypt: Multicenter national project

AIM

To assess the effectiveness of hepatitis B virus (HBV) vaccination program among fully vaccinated children.

METHODS

A national community based cross-sectional study was carried out in 6 governorates representing Egypt. A total of 3600 children aged from 9 mo to 16 years who were fully vaccinated with HBV vaccine during infancy were recruited. Face to face interviews were carried out and sera were evaluated for hepatitis B surface antigen (HBsAg), anti-HBV core antibodies (total) and quantitative detection of hepatitis B surface antibody using enzyme linked immunoassays techniques. Samples positive to HBsAg/anti-HBV core antibodies were subjected to quantitative HBV-DNA detection by real time polymerase chain reaction with 3.8 IU/L detection limit.

RESULTS

Sero-protection was detected among 2059 children (57.2%) with geometric mean titers 75.4 ± 3.6 IU/L compared to 3.1 ± 2.1 IU/L among non-seroprotected children. Multivariate logistic analysis revealed that older age and female gender were the significant predicting variables for having non sero-protective level, with adjusted odds ratio 3.3, 9.1 and 14.2 among children aged 5 to < 10, 10 to < 15 and ≥ 15 years respectively compared to those < 5 years and 1.1 among girls compared to boys with P < 0.01. HBsAg was positive in 0.11% and breakthrough infection was 0.36% and 0.39% depending on positivity of anti-HBc and DNA detection respectively. The prevalence of HBV infection was significantly higher among children aged ≥ 7 years (0.59%) compared to 0.07% among younger children with odds ratio equal to 8.4 (95%CI: 1.1-64.2) and P < 0.01.The prevalence was higher among girls (0.48%) than boys (0.29%) with P > 0.05.

CONCLUSION

The Egyptian compulsory HBV vaccination program provides adequate protection. Occult HBV infection exists among apparently healthy vaccinated children. Adherence to infection control measures is mandatory.

Three decades of hepatitis B control with vaccination

Hepatitis B virus (HBV) continues to represent a major health problem and can lead to acute liver failure, acute hepatitis, chronic carriership, chronic hepatitis of HBV, liver cirrhosis, liver cancer, liver transplantation and death. There is a marked difference in the geographic distribution of carriers. More than 240 million people worldwide are chronic HBV carriers. Mother-to-child transmission remains the most important mechanism of infection in countries with a high prevalence of HBV. Percutaneous/parenteral transmission and unsafe sexual practices are important mode of spread transmission of HBV in other countries. Vaccination against HBV is the gold measure for primary prevention and control of the disease. Currently, 179 countries have added HBV vaccination to their routine vaccination programs with great results. Neonatal immunization with HBV vaccine has been one of the most highly effective measures in public health and the first anti-cancer program to be launched. In this paper we review the achievements for the last three decades.

Detection and circulation of hepatitis B virus immune escape mutants among asymptomatic community dwellers in Ibadan, southwestern Nigeria

BACKGROUND

In 2012, the first Nigerian Hepatitis B Virus (HBV) immune escape mutant (IEM) case was detected in a pregnant woman in southwestern Nigeria. Consequently, this study was designed to investigate the presence and possible circulation of IEMs amongst asymptomatic community dwellers in southwestern Nigeria.

METHODS

Blood specimens collected from 438 asymptomatic community dwellers were screened for HBsAg using ELISA technique. Subsequently, the S-gene was amplified in HBsAg positive samples by a nested PCR protocol, and amplicons sequenced. Isolates were then subtyped by amino acid residues at positions 122, 127, 134 and 160, and genotyped by phylogenetic analysis.

RESULTS

Of the 31 (7.08%) samples positive for HBsAg, the ∼ 408 bp Sgene fragment was successfully amplified and sequenced in 27. Samples obtained from 4 patients could not be amplified due to low titres. Sequence data from only 15 of the isolates could be analysed further as eight of the remaining 12 had multiple peaks while the rest three showed no similarity to any HBV gene when subjected to BLAST analysis. Thirteen of the 15 isolates were identified as genotype E. Eleven of which were subtyped as ayw4 while the remaining two could not be subtyped due to sR122Q/P substitutions. The last two isolates that could not be genotyped and subtyped had other mutations in the "a" determinant associated with IEMs.

CONCLUSIONS

This study confirmed presence and circulation of HBV IEM in Nigeria, the country's inclusion in the genotype E crescent, and the value of phylogenetic analysis in HBV identification.

Induced immunity against hepatitis B virus

Prevention of hepatitis B virus (HBV) infection with its consequent development of HBV chronic liver disease and hepatocellular carcinoma is a global mandatory goal. Fortunately, safe and effective HBV vaccines are currently available. Universal hepatitis B surface antigen HBV vaccination coverage is almost done. Growing knowledge based upon monitoring and surveillance of HBV vaccination programs has accumulated and the policy of booster vaccination has been evaluated. This review article provides an overview of the natural history of HBV infection, immune responses and the future of HBV infection. It also summarizes the updated sources, types and uses of HBV vaccines, whether in the preclinical phase or in the post-field vaccination.

Oncogenic viruses and hepatocellular carcinoma

About 80% of hepatocellular carcinoma (HCC) is caused by hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections especially in the setting of established cirrhosis or advanced fibrosis, making HCC prevention a major goal of antiviral therapy. HCC tumors are highly complex and heterogeneous resulting from the aberrant function of multiple molecular pathways. The roles of HCV or HBV in promoting HCC development are still either directly or indirectly are still speculative, but the evidence for both effects is compelling. In patients with chronic hepatitis viral infection, cirrhosis is not a prerequisite for tumorigenesis.

Prevention of hepatitis B

Hepatitis B virus (HBV) causes life-threatening liver disease. It is transmitted through a horizontal route or a mother-to-infant route, and the latter is the major route in endemic areas. Prevention of HBV infection by immunization is the best way to eliminate HBV-related diseases. The HBV vaccine is the first human vaccine using a viral antigen from infected persons, which is safe and effective. Either passive immunization by hepatitis B immunoglobulin (HBIG) or active immunization by HBV vaccine is effective, and a combination of both yields the best efficacy in preventing HBV infection. The impact of universal HBV immunization is huge, with 90%-95% effectiveness in preventing chronic HBV infection. It is the first cancer preventive vaccine with a protective efficacy against hepatocellular carcinoma (HCC) of ∼ 70%. Nevertheless, further effort is still needed to avoid vaccine failure and to increase the global coverage rate.

MICA SNPs and the NKG2D system in virus-induced HCC

Hepatocellular carcinoma (HCC) is one of the most frequent causes of cancer-related death globally. Above well-known risk factors for HCC development ranging from various toxins to diseases such as diabetes mellitus, chronic infection with hepatitis B virus and hepatitis C virus (HCV) poses the most serious threat, constituting the cause in more than 80 % of cases. In addition to the viral genes intensively investigated, the pathophysiological importance of host genetic factors has also been greatly and increasingly appreciated. Genome-wide association studies (GWAS) comprehensively search the host genome at the single-nucleotide level, and have successfully identified the genomic region associated with a whole variety of diseases. With respect to HCC, there have been reports from several groups on single nucleotide polymorphisms (SNPs) associated with hepatocarcinogenesis, among which was our GWAS discovering MHC class I polypeptide-related sequence A (MICA) as a susceptibility gene for HCV-induced HCC. MICA is a natural killer (NK) group 2D (NKG2D) ligand, whose interaction with NKG2D triggers NK cell-mediated cytotoxicity toward the target cells, and is a key molecule in tumor immune surveillance as its expression is induced on stressed cells such as transformed tumor cells for the detection by NK cells. In this review, the latest understanding of the MICA-NKG2D system in viral HCC, particularly focused on its antitumor properties and the involvement of MICA SNPs, is summarized, followed by a discussion of targets for state-of-the-art cancer immunotherapy with personalized medicine in view.

Detection of hepatitis B virus isolates with mutations associated with immune escape mutants among pregnant women in Ibadan, southwestern Nigeria

Perinatal transmission of hepatitis B virus (HBV) and its associated immune escape mutants (IEMs), is the major vehicle through which a population of chronically infected people who serve as infectious HBV reservoirs is maintained in communities. Therefore, to assess the risk of perinatal transmission, 272 pregnant women attending ante-natal clinics in Ibadan metropolis, southwestern, Nigeria, were screened for HBsAg using ELISA technique. Samples positive for HBsAg were subjected to HBV DNA detection by PCR amplification of the S-gene and amplicon sequencing. Isolates were genotyped and subtyped using a combination of molecular techniques.

Fifteen (5.5%) of the pregnant women were positive for HBsAg of which HBV DNA was detected in seven. Five of the isolates were typed as genotype E subtype ayw4 using amino acid residues at positions 122, 127, 134 and 160. Another could only be typed as genotype E subtype ayw4 by further phylogenetic analysis. The remaining one isolate did not belong to any of genotypes A – H. Three of the HBV isolates including the untypable, had mutations in the ‘a’ determinant associated with IEMs.

This study confirms the endemicity of HBV, the risk of perinatal transmission and the circulation of genotype E subtype ayw4 in Nigeria. It further demonstrates the presence of IEMs in Nigeria.

Prophylactic vaccination against hepatitis B: achievements, challenges and perspectives

Large-scale vaccination against hepatitis B virus (HBV) infection started in 1984 with first-generation vaccines made from plasma of chronic carriers containing HBV surface antigen (HBsAg). Thereafter, it was replaced in most countries by second-generation vaccines manufactured in yeast cells transformed with gene S encoding HBsAg. Both generations of vaccines have been applied for universal neonate and early childhood vaccination worldwide and have led to a 70-90 % decrease in chronic HBV carrier rates. However, 10-30% of newborns from HBsAg/HBeAg-positive mothers cannot be protected by passive/active vaccination alone and become chronic HBV carriers themselves. Asymptomatic occult HBV infections are frequent even in those who have protective levels of anti-HBs. Suboptimal protection may be due to heterologous HBsAg subtypes that are present in 99% of HBV carriers worldwide. Second-generation vaccines contain partially misfolded HBsAg and lack preS1 antigen that carries the major HBV attachment site and neutralizing epitopes. Third-generation vaccines produced in mammalian cells contain correctly folded HBsAg and neutralizing epitopes of the preS antigens, induce more rapid protection, overcome nonresponse to second-generation vaccines and, most importantly, may provide better protection for newborns of HBV-positive mothers. PreS/S vaccines expressed in mammalian cells are more expensive to manufacture, but introduction of more potent HBV vaccines should be considered in regions with a high rate of vertical transmission pending assessment of health economics and healthcare priorities. With optimal vaccines and vaccination coverage, eradication of HBV would be possible.

In vitro and in vivo replication of a chemically synthesized consensus genome of hepatitis B virus genotype B

Hepatitis B virus (HBV) genotypes vary in their geographical distribution and virological features. Previous investigations have shown that HBV genotype B is a predominant HBV genotype in China. Studies on HBV concerning different isolates frequently meet the question about the HBV reference strain and its representativeness. Although HBV consensus sequences can be generated easily by sequence alignment, they may not exist in nature or could not usually be isolated from patient samples. Thus, the construction of a consensus HBV genome has been proposed. In this study, an HBV genotype B consensus sequence was established by comparing 42 full-length HBV genotype B sequences and the genome was generated by chemical synthesis. This consensus genome was fully replication competent by in vitro transfection into hepatoma cells. The plasmid pHBV1.3B carrying a 1.3× full-length HBV consensus genome was hydrodynamically injected into Balb/c mice. HBsAg, anti-HBs, HBeAg, anti-HBe, and anti-HBc detection indicated expression and replication of this HBV genome in mice, similar to other HBV isolates. This approach represents a strategy to design and create consensus HBV genomes for future studies.

Efficacy of prolonged tenofovir therapy on hepatitis delta in HIV-infected patients

BACKGROUND

Hepatitis delta virus (HDV) produces the most severe form of chronic viral hepatitis. We explored whether prolonged tenofovir exposure might be beneficial on hepatitis delta in HIV-infected patients.

METHODS

All HIV-infected patients with hepatitis delta followed at our institution since year 2000 were retrospectively examined. Serum HBV-DNA and HDV-RNA were quantified using commercial assays. Liver fibrosis was measured using elastometry.

RESULTS

A total of 19 HIV/delta patients were identified. All were viremic for HDV and 11 for HBV. After a median tenofovir exposure of 58 months, all had undetectable HBV-DNA and 10 (53%) had undetectable HDV-RNA. The median drop in HDV-RNA in the remaining nine HDV viremic patients at the end of follow-up was 2.4 log copies/ml. A reduction above 30% in liver stiffness occurred in six out 10 (60%) patients who achieved undetectable HDV-RNA, whereas hepatic stiffness did not change in the remaining HDV viremic patients (P = 0.03). Serum HBsAg concentrations did not decline significantly, although HBsAg seroclearance occurred in three patients, all of whom became negative for HDV-RNA.

CONCLUSION

Long-term exposure to tenofovir significantly reduced serum HDV-RNA apart from completely suppressing HBV-DNA in HIV-infected patients with hepatitis delta. This virological benefit is accompanied by significant improvements in liver fibrosis.

Detection of volatile malodorous compounds in breath: current analytical techniques and implications in human disease

For the last few decades intense scientific research has been placed on the relationship between trace substances found in exhaled breath such as volatile organic compounds (VOC) and a wide range of local or systemic diseases. Although currently there is no general consensus, results imply that VOC have a different profile depending on the organ or disease that generates them. The association between a specific pathology and exhaled breath odor is particularly evident in patients with medical conditions such as liver, renal or oral diseases. In other cases the unpleasant odors can be associated with the whole body and have a genetic underlying cause. The present review describes the current advances in identifying and quantifying VOC used as biomarkers for a number of systemic diseases. A special focus will be placed on volatiles that characterize unpleasant breath 'fingerprints' such as fetor hepaticus; uremic fetor; fetor ex ore or trimethylaminuria.

Molecular virology of hepatitis B virus and targets for antiviral intervention

The members of the viral family Hepadnaviridae comprise one of the smallest enveloped DNA viruses and cause acute and chronic infections in mammals and birds, leading to large virus and antigen loads in the blood. They have a restricted host range and depend on differentiated hepatocytes for replication. Hepatitis B virus (HBV) is the prototype of the Hepadnaviridae. HBV can persist in infected hepatocytes and has evolved elaborate strategies to evade the immune system. HBV replicates like HIV (family of Retroviridae) via reverse transcription. Drugs licensed for inhibition of HIV reverse transcriptase lower the viral load of chronic HBV patients, but they do not cure the infection. HBV genomes are archived in the nucleus of hepatocytes as episomal DNA before reverse transcription. In contrast, the RNA genome of HIV first needs reverse transcription before proviral integration within the host genome. Wild-type HBV remains relatively stable in chronic HBV patients during the immunotolerant state, but is able to evolve mutants rapidly upon selective pressure due to therapy or immune reactions. Current therapies for chronic hepatitis B are far from optimal. To extend therapeutic options, further studies on HBV and its interaction with the host are urgently needed.

Hepatitis A virus in the Middle East and North Africa region: a new challenge

During the past three decades, a gradual shift in the age of infection with hepatitis A virus (HAV) from early childhood to adulthood has been observed. There is a general lack of updated data on HAV burden of disease, incidence and age-specific seroprevalence in countries of the Middle East and North Africa (MENA) region. The aim of this article is to review the published data on anti-HAV seroprevalence, an important tool to monitor infections rates, in countries of the MENA region and associated risk factors including water and socioeconomic data when available. Data on anti-HAV seroprevalence were found for 12 of 25 MENA countries. We show that MENA countries, similar to other areas in the world, have a clear shift in HAV incidence with a decline among young age groups and an increase among adults and older individuals. This would likely be associated with increased morbidity and increased risks of outbreaks among younger age groups. Consequently, the continuous surveillance of hepatitis A cases and the inclusion of hepatitis A vaccine in the expanded immunization programmes are needed in countries of the MENA.

Suppression of La antigen exerts potential antiviral effects against hepatitis A virus

BACKGROUND

Despite the development and availability of hepatitis A virus (HAV) vaccine, HAV infection is still a major cause of acute hepatitis that occasionally leads to fatal liver disease. HAV internal ribosomal entry-site (IRES) is one of the attractive targets of antiviral agents against HAV. The aim of the present study is to evaluate the impact of La, one of the cellular proteins, on HAV IRES-mediated translation and HAV replication.

METHODS AND FINDINGS

We investigated the therapeutic feasibility of siRNAs specific for cellular cofactors for HAV IRES-mediated translation in cell culture. It was revealed that siRNA against La could inhibit HAV IRES activities as well as HAV subgenomic replication. We also found that the Janus kinase (JAK) inhibitors SD-1029 and AG490, which reduce La expression, could inhibit HAV IRES activities as well as HAV replication.

CONCLUSIONS

Inhibition of La by siRNAs and chemical agents could lead to the efficient inhibition of HAV IRES-mediated translation and HAV replication in cell culture models. La might play important roles in HAV replication and is being exploited as one of the therapeutic targets of host-targeting antivirals.

Molecular identification of hepatitis B virus genotypes/subgenotypes: revised classification hurdles and updated resolutions

The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term "recombino-subgenotype". Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term "immigro-subgenotype" to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.

Hepatitis B virus DNA quantification with the three-in-one (3io) method allows accurate single-step differentiation of total HBV DNA and cccDNA in biopsy-size liver samples

BACKGROUND

Hepatitis B virus (HBV) replicates via reverse transcription converting its partially double stranded genome into the covalently closed circular DNA (cccDNA). The long-lasting cccDNA serves as a replication intermediate in the nuclei of hepatocytes. It is an excellent, though evasive, parameter for monitoring the course of liver disease and treatment efficiency.

OBJECTIVE

To develop and test a new approach for HBV DNA quantification in serum and small-size liver samples.

STUDY DESIGN

The p3io plasmid contains an HBV fragment and human β-actin gene (hACTB) as a standard. Respective TaqMan probes were labeled with different fluorescent dyes. A triplex real-time PCR for simultaneous quantification of total HBV DNA, cccDNA and hACTB could be established.

RESULTS

Three-in-one method allows simultaneous analysis of 3 targets with a lower limit of quantification of 48 copies per 20 μl PCR reaction and a wide range of linearity (R(2)>0.99, p<0.0001) for all measured sequences. The method showed a pan-genotypic specificity among genotypes A-F with serum DNA samples from HBV infected patients. Total HBV DNA and cccDNA could be quantified in 32 and 22 of 33 FFPE preserved liver specimens, respectively. Total HBV DNA concentrations quantified by the 3io method remained comparable with Cobas TaqMan HBV Test v2.0.

CONCLUSIONS

The three-in-one protocol allows the single step quantification of viral DNA in samples from different sources. Therefore lower sample input, faster data acquisition, a lowered error and significantly lower costs are the advantages of the method.

Emerging and re-emerging enteric viruses causing multinational foodborne disease outbreaks

ABSTRACT: 

The development of molecular detection methods has led to recognition of viruses as important foodborne pathogens. The most common foodborne virus is norovirus, which together with HAV are transmitted via food consumed raw, such as shellfish, fresh produce and soft fruit. HEV is increasingly being recognized as an emerging foodborne virus in developed countries. The transmission route of HEV includes zoonotic transmission in association with pork products. Ongoing changes in food commerce and production from national to internationally-distributed foodstuffs are leading to widespread infections and multinational outbreaks. Recent large viral outbreaks have been linked to oysters, frozen berries and semidried tomatoes.

Will there be a vaccine to prevent HCV infection?

Prevention of hepatitis C virus (HCV) infection by vaccination has been a priority since discovery of the virus and the need has not diminished over the past 25 years. Infection rates are increasing in developed countries because of intravenous drug use. Reducing transmission will be difficult without a vaccine to prevent persistence of primary infections, and also secondary infections that may occur after cure of chronic hepatitis C with increasingly effective direct-acting antiviral (DAA) regimens. Vaccine need is also acute in resource poor countries where most new infections occur and DAAs may be unaffordable. Spontaneous resolution of HCV infection confers durable protection, but mechanisms of immunity remain obscure and contested in the context of vaccine design. A vaccine must elicit a CD4+ helper T cell response that does not fail during acute infection. The need for neutralizing antibodies versus cytotoxic CD8+ T cells is unsettled and reflected in the design of two very different vaccines evaluated in humans for safety and immunogenicity. Here we review the status of vaccine development and the scientific and practical challenges that must be met if the burden of liver disease caused by HCV is to be reduced or eliminated.

Prevention of hepatocellular carcinoma in chronic viral hepatitis B and C infection

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, with the majority of cases associated with persistent infection from hepatitis B virus (HBV) or hepatitis C virus (HCV). Natural history studies have identified risk factors associated with HCC development among chronic HBV and HCV infection. High-risk infected individuals can now be identified by the usage of risk predictive scores. Vaccination plays a central role in the prevention of HBV-related HCC. Treatment of chronic HBV infection, especially by nucleoside analogue therapy, could also reduce the risk of HBV-related HCC. Concerning HCV infection, besides the advocation of universal precautions to reduce the rate of infection, pegylated interferon and ribavirin could also reduce the risk of HCV-related HCC among those achieving a sustained virologic response. Recently there has been mounting evidence on the role of chemopreventive agents in reducing HBV- and HCV-related HCC. The continued advances in the understanding of the molecular pathogenesis of HCC would hold promise in preventing this highly lethal cancer.

Socio-demographic and behavioral determinants of hepatitis B vaccination and infection in pregnant women on Mayotte Island, Indian Ocean

BACKGROUND

Socio-demographic and behavioral determinants of Hepatitis B virus (HBV) vaccination and infection among pregnant women (PW) of Mayotte Island (Indian Ocean) are not well understood.

METHODS

Six hundred and seventy-one pregnant women presenting to public antenatal clinics on Mayotte Island were included between September 15, 2008 and September 27, 2009. Socio-demographics, sexual risk behavior characteristics, and data for HBV biomarkers were collected. Logistic regression was undertaken to study determinants of HBV vaccination and factors associated with the risk of HBV infection were assessed using a survival method adapted to interval-censored data. Due to missing data for HBV biomarkers, data were analyzed using multiple imputation (MI).

RESULTS

Past or recent HBV infection was observed for 35.5% (95% confidence interval (CI): 30.4-40.8) of PW and 18.6% (95% CI: 14.7-23.2) had evidence of HBV vaccination. PW with unemployed and education qualification (adjusted odds ratio (aOR) 2.65, 95% CI 1.52-4.60) and student status (aOR 4.79, 95% CI 1.63-4.07) were better vaccinated against HBV, compared to those without employment and education. Being born on Comoros was associated with a 63% reduction in HBV vaccination (aOR 0.37, 95% CI 0.21-0.65), compared to be born in Mayotte/France. Women with a history of sexually-transmitted infections in the last 5 years had an increased risk of HBV infection (adjusted hazard ratio (aHR) 3.10, 95% CI: 1.13-8.50), whereas those who sometimes used condoms had a 60% reduced risk (aHR=0.40, 95% CI: 0.23-0.69).

CONCLUSIONS

Socio-demographic factors were identified for HBV vaccination, while behavioral factors were observed for HBV infection. These results could help to determine priorities for intervention.