Tracing hepatitis C and Delta viruses to estimate their contribution in HCC rates in Mongolia

Risk factors associated with hepatitis D virus infection and preventive strategies in Mongolia

BACKGROUND

Hepatitis D virus (HDV) infection is highly prevalent in Mongolia. We aimed to identify the risk factors associated with HDV infection, propose preventive strategies, and evaluate the outcomes of a 3-year collaborative project between Taiwan and Mongolia.

METHODS

In 2016 and 2018, we conducted onsite visits to Mongolia. Mongolian investigators collected questionnaires focusing on risk factors, demographic characteristics, and serum samples for acute HDV infections. Furthermore, 19 Mongolian seed teachers participated in a 1-week workshop on infection control in Taiwan. Subsequently, these seed teachers trained more than 400 medical personnel in Mongolia. To assess secular changes in acute HDV infection, we reviewed the registration data from the National Center for Communicable Disease (NCCD) in Mongolia between 2011 and 2021.

RESULTS

Among the 194 Mongolian patients, 108 had dual infection with hepatitis B virus (HBV) and HDV, while 86 had acute hepatitis B (AHB). Patients with HBV/HDV dual infections were older (28.6 vs 25.5 years, p = 0.030) and had lower rates of positive hepatitis B e antigen in their sera, lower rates of serum HBV DNA exceeding 2000 IU/mL, and higher rates of having received dental treatment (59.4% vs 40.5%, p = 0.014) and injection therapy (64.2% vs 44.0%, p = 0.009) compared with those with AHB. Analysis of NCCD data revealed that new HDV infection cases were more prevalent between 2011 and 2015 (111.20 ± 29.79 cases/y) and decreased to 54.67 ± 27.34 cases/y between 2016 and 2021 ( p = 0.010).

CONCLUSION

Dental treatment and injections were associated with a higher risk of acute HDV infections in Mongolia. Through collaborative efforts, the incidence rate of HDV infection has declined in recent years.

The Dynamics of the Prevalence of Acute Viral Hepatitis and the Strategies against Viral Hepatitis in Mongolia

Background

Hepatocellular carcinoma (HCC) is the most common cancer in Mongolia. The relative importance of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in HCC etiology is known to vary greatly from one part of the world to another. Principally, 95% of HCC patients have chronic viral hepatitis, including 53% hepatitis B virus, 38.9% HCV, and 5.6% have HBV/HCV coinfection. Hepatitis D virus (HDV) infection is widely spread in our country, anti-HDV has been found in more than 25% of carriers who have HBsAg.

Materials and methods

We analyzed data of patients who had been diagnosed with acute viral hepatitis in the Department of adult hepatitis, National Center for Communicable Diseases in Mongolia from 1952 to 2018.

Results

A total of 318,831 cases of acute viral hepatitis were registered in Mongolia between 1981 and 2019, which is 34.9 cases per 10,000 population. Of these, 265,931 cases of acute viral hepatitis A, or 28.6 per 10,000 populations, 48,855 cases of acute viral hepatitis B, or 5.5 cases per 10,000 populations, and 2,607 cases of acute viral hepatitis C, or 0.4 cases per 10,000 populations were recorded.

Conclusion

The prevalence of viral hepatitis in our country was the highest in 1981-1991, but since 2012, the prevalence of infection has steadily decreased. In Mongolia, since 1960, multifaceted programs and activities to combat viral hepatitis have been successfully implemented at the national level.

How to cite this article

Badamnachin B, Badamjav T, Dondov G, et al. The Dynamics of the Prevalence of Acute Viral Hepatitis and the Strategies against Viral Hepatitis in Mongolia. Euroasian J Hepato-Gastroenterol 2024;14(1):65-69.

High Prevalence of Chronic Viral Hepatitis and Liver Fibrosis Among Mongols in Southern California

BACKGROUND

Mongolia is a highly endemic region for chronic hepatitis B (HBV), hepatitis delta (HDV), and hepatitis C (HCV) infections. Aim of this study was to comprehensively characterize chronic viral hepatitis among Mongols living in Southern California.

METHODS

Three screening events were conducted between August and November 2018, with 528 adult Mongols tested for HBV and HCV. HBsAg (+) individuals (CHB) underwent additional testing for HDV RNA and anti-HDV. Liver tests, platelet count, and FibroScan™ were performed on CHB and chronic HCV (CHC) individuals.

RESULTS

Fifty-one out of 534 were HBsAg reactive (9.7%), and all were foreign-born. Mean age of CHB individuals was 37.8 (range 18-69) years. Forty-six out of 51 were HBeAg (-). HBV genotypes were exclusively D2 or A1. Twenty-one out of 51 (41.2%) were anti-HDV (+) and 17/51 (33.3%) were HDV RNA (+). HDV RNA (+) individuals had significantly higher ALT, fibrosis-4 score, and liver stiffness compared to HDV RNA (-) individuals. Incidence of advanced fibrosis was higher in HDV RNA (+) individuals (57% vs. 13%, p = 0.013). Forty-eight (9.1%) individuals were anti-HCV (+) and 19 (3.6%) were HCV RNA (+). Mean age of CHC individuals was 40.2 (range 28-71) years. Prevalence of anti-HCV (+) was higher among those born between 1945 and 1965 versus those born after 1965 (18.8% vs. 7.9%, p = 0.025). Genotype 1b was predominant. Incidence of cirrhosis was 7% among all participants.

CONCLUSIONS

Mongols living in the USA are at high risk for CHB and CHC infections. One-third of CHB individuals had CHD superinfection with advanced fibrosis. Universal screening for viral hepatitis in Mongols in the USA is mandatory.

Prevalence and genotype distribution of hepatitis C virus in Mongolia: Systematic review and meta-analysis

OBJECTIVE

To characterize hepatitis C virus (HCV) infection epidemiology in Mongolia.

METHOD

Publications on HCV antibody (Ab) and RNA prevalence, and/or genotypes/subtypes were systematically reviewed and reported following PRISMA guidelines. Random-effects meta-analyses and age adjustments were conducted to estimate the prevalence of Mongolians exposed to HCV (pooled HCV-Ab prevalence) by time period, sex, and at-risk populations; and to estimate the prevalence of chronically-infected HCV individuals.

RESULTS

The national pooled HCV-Ab prevalence was 12.3% in 2000-2009 and 11.2% in 2013. Sex-specific pooled prevalence appeared higher among females than males (14.0% versus 6.8%). Age-specific pooled prevalence significantly increased from 3.7% among children (aged 0-10 years) to 34.1% among people aged ≥50 years (p < 0.001). Among the adult general population (low-risk population), the national age-adjusted prevalence was 8.1%. Age-adjusted chronic infection prevalence in adults was 6.0%. Among healthcare workers, pooled prevalence was 18.0%. Among patients with liver diseases, pooled prevalence was 53.7%. Among individuals engaging in risky sexual behaviors, pooled prevalence was 11.1%. The identified circulating genotypes/subtypes were 1b (58.0%), 2a (21.7%), and 1a (20.2%).

CONCLUSION

The national HCV prevalence in Mongolia appeared to be among the highest worldwide. Higher prevalence in the clinical setting indicated potential ongoing HCV iatrogenic and occupational transmission. Additionally, HCV transmission in community settings should be investigated.

Liver Cancer in Nepal

Hepatocellular carcinoma (HCC) is highly incidental in South Asian countries. Nepal, however, has low incidence for HCC owing to low prevalence for hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. Nepal lacked national cancer registry until 2003. Though there has been some effort in having one, the current registry incorporates twelve centers and may not properly represent the total cancer burden in the country. Serology for HBV and HCV is seen to be positive in nearly 25 to 30% and 5 to 10% of HCCs respectively. Clinical characteristics of HCCs in Nepal have been discussed in this mini-review and it features poor performance status and advanced stage at presentation, making only a small fraction of these subjects eligible for curative treatment options. Most of the standard treatment modalities are available in Nepal and appear to be reasonably affordable as compared with other developed nations.

How to cite this article: Shrestha A. Liver Cancer in Nepal. Euroasian J Hepato-Gastroenterol 2018;8(1):63-65.

Epidemiology, Genotype Distribution, Prognosis, Control, and Management of Viral Hepatitis B, C, D, and Hepatocellular Carcinoma in Mongolia

Mongolia is located between Russia and China. The total population of Mongolia as of December 2017 is estimated to be 3.2 million people. According to our previous study results, the prevalence of HBV was 11.8%, and anti-HDV was detected in 4.8% among the HBsAg-positive subjects. Interestingly, most HCV infection is caused by genotype 1b. Among all HBV DNA-positive samples, 98.5% were classified into genotype D, and regarding HDV genotypes, all HDV RNA-positive samples, 100%, were classified into genotype I. The second study is the baseline survey of a Nationwide Cancer Cohort Study. Prevalence of HBsAg was 10.6%. Additionally, HCV infection was observed in 9.9%, and 0.8% were coinfected with HBV and HCV among the general population aged from 10 to 64 years. The third study investigated the population-based prevalence of hepatitis B and C virus in apparently healthy population of Ulaanbaatar city, Mongolia. The anti-HCV prevalence was 9.0%. In addition, the prevalence of HBV was 8.0%. The fourth study is on the prevalence of HCV and coinfections among nurses in a tertiary hospital in Mongolia. The prevalence of HCV was 18.9%. Additionally, HBV infection was observed in 23.1%, and 1.2% were coinfected with HCV and HBV. Mongolia has the highest HCC incidence in the world (78.1/100,000, 3.5* higher than China). As a result, the Mongolia government has launched The National Viral Hepatitis Program, which is a comprehensive program that involves all aspects from prevention to care and disease control to meet a reduction goal for morbidity and mortality due to HBV, HCV, and HDV. Consequently, access to antiviral therapies is now improving in Mongolia. How to cite this article: Baatarkhuu O, Gerelchimeg T, Munkh-Orshikh D, Batsukh B, Sarangua G, Amarsanaa J. Epidemiology, Genotype Distribution, Prognosis, Control, and Management of Viral Hepatitis B, C, D, and Hepatocellular Carcinoma in Mongolia. Euroasian J Hepato-Gastroenterol 2018;8(1):57-62.

Endemic prevalence of hepatitis B and C in Mongolia: A nationwide survey amongst Mongolian adults

In this study, a representative group of Mongolian adults was tested for hepatitis B virus (HBV) and hepatitis C virus (HCV). Screening was conducted at 17 different locations on a randomly sampled group, representing the Mongolian adult population. A total of 1158 adults, 500 (43.1%) men and 659 (56.9%) women were included. The prevalence estimates of HBV and HCV amongst the general Mongolian adult population were found to be 11.1%±1% (SE) and 8.5%±0.7% or 207 418 and 160 228 cases, respectively. For HCV, the majority of cases are concentrated in older age groups with a prevalence of 25.8% amongst those aged 50 years and above, whilst the prevalence of HBV does not vary significantly amongst age groups. For both, HBV and HCV, the data indicate a higher risk of infection and a higher mortality because of the hepatitis amongst men than amongst women. This study represents the first nationwide estimate of the prevalence of HBV in Mongolia and also considered the first for HCV since 2005 and confirm the position of Mongolia as one of the hot-spots of chronic hepatitis infection in the world with about 19.4% of the adult population being infected with either HBV or HCV.

Hepatitis C virus seroprevalence in the general female population of 9 countries in Europe, Asia and Africa

BACKGROUND

New oral treatments with very high cure rates have the potential to revolutionize global management of hepatitis C virus (HCV), but population-based data on HCV infection are missing in many low and middle-income countries (LMIC).

METHODS

Between 2004 and 2009, dried blood spots were collected from age-stratified female population samples of 9 countries: China, Mongolia, Poland, Guinea, Nepal, Pakistan, Algeria, Georgia and Iran. HCV antibodies were detected by a multiplex serology assay using bead-based technology.

RESULTS

Crude HCV prevalence ranged from 17.4% in Mongolia to 0.0% in Iran. In a pooled model adjusted by age and country, in which associations with risk factors were not statistically heterogeneous across countries, the only significant determinants of HCV positivity were age (prevalence ratio for ≥45 versus <35 years = 2.84, 95%CI 2.18-3.71) and parity (parous versus nulliparous = 1.73, 95%CI 1.02-2.93). Statistically significant increases in HCV positivity by age, but not parity, were seen in each of the three countries with the highest number of HCV infections: Mongolia, Pakistan, China. There were no associations with sexual partners nor HPV infection. HCV prevalence in women aged ≥45 years correlated well with recent estimates of female HCV-related liver cancer incidence, with the slight exception of Pakistan, which showed a higher HCV prevalence (5.2%) than expected.

CONCLUSIONS

HCV prevalence varies enormously in women worldwide. Medical interventions/hospitalizations linked to childbirth may have represented a route of HCV transmission, but not sexual intercourse. Combining dried blood spot collection with high-throughput HCV assays can facilitate seroepidemiological studies in LMIC where data is otherwise scarce.

Screening and management of viral hepatitis and hepatocellular carcinoma in Mongolia: results from a survey of Mongolian physicians from all major provinces of Mongolia

Background

According to Globocan, Mongolia has the highest worldwide hepatocellular carcinoma (HCC) incidence (78.1/100 000, 3.5× higher than China).

Aims and methods

We conducted an anonymous survey of physicians from major provinces who attended an educational liver symposium, analysing their demography, practice, knowledge, perceptions and proposed solutions. Multivariate logistic regression was used to estimate OR relating demography and practice factors with higher provider knowledge and improvement.

Results

Of the 121 attendees, 44–95 (36–79%) responded to each question. Most were female (87%), young (79% age <50), subspecialists (81%), university-affiliated (74%), and practised in urban areas (61%). The mean pretest and post-test scores per physician were 60.4±20.4 and 65.6±21.3, with no observed significant predictors for baseline knowledge or improvement. Most (>80%) noted that <50% of patients who need hepatitis or HCC screening receive it. The main perceived barriers to screening were inability to pay for tests, lack of guidelines and poor patient awareness. Hepatitis treatment rates were low; 83% treated hepatitis C virus in <10 patients in the past year, and 86% treated hepatitis B virus in <10 patients/month. Treatment barriers were multifactorial, with cost as a principal barrier. Proposed solutions were universal screening policies (46%), removal of financial barriers (28%) and provider education (20%).

Conclusions

Physicians from major regions of Mongolia noted low screening for viral hepatitis, even lower treatment rates, financial barriers and the need for increased educational efforts. We advocate broad-based medical education tailored to local needs and based on needs assessment and outcome measurements.

Hepatitis C Virus Seroprevalence in Mongolian Women Assessed by a Novel Multiplex Antibody Detection Assay

BACKGROUND

Hepatitis C virus (HCV) infection causes hepatocellular carcinoma and is an important cause of mortality in both industrialized and developing countries. We developed a single-step high-throughput multiplex serology assay for HCV antibody detection and determined HCV prevalence in a highly endemic country.

METHODS

Five proteins (Core, NS3, NS4A, NS5A, NS5B) each from the three most common subtypes of HCV (1a, 1b, 2a) were recombinantly expressed and used as antigens in a multiplexed antibody detection assay. Multiplex HCV serology was validated with 432 reference sera whose HCV status was established by commercial ELISA, Western blot, and RNA assays. HCV antibodies were determined in 1,023 sera representative for the adult female population of Mongolia.

RESULTS

In reference sera, detection of HCV (mostly Core and NS3) antibodies by multiplex serology showed 100% sensitivity and 99.6% specificity, and was in very good agreement with the commercial diagnostic assays (kappa, 0.96; 95% confidence interval, 0.92-0.99). The role of antibodies to NS4 and NS5 remains to be evaluated. In Mongolia, overall HCV antibody prevalence was 18.9% (17.8% when age-standardized to the world population). HCV seroprevalence increased with age from 10% in women <30 years to 32% in women ≥50 years, but was not related to sexual risk factors.

CONCLUSIONS

The single-step high-throughput multiplex HCV serology assay performs similarly to conventional HCV antibody screening followed by secondary confirmation assays. A very high HCV seroprevalence was confirmed across all socio-economic groups in the female population of Mongolia.

IMPACT

Multiplex HCV serology facilitates large seroepidemiologic studies of HCV infection.

Hepatitis D and hepatocellular carcinoma

Hepatitis D virus (HDV) is a defective circular shape single stranded HDV RNA virus with two types of viral proteins, small and large hepatitis D antigens, surrounded by hepatitis B surface antigen. Superinfection with HDV in chronic hepatitis B is associated with a more threatening form of liver disease leading to rapid progression to cirrhosis. In spite of some controversy in the epidemiological studies, HDV infection does increase the risk of hepatocellular carcinoma (HCC) compared to hepatitis B virus (HBV) monoinfection. Hepatic decompensation, rather than development of HCC, is the first usual clinical endpoint during the course of HDV infection. Oxidative stress as a result of severe necroinflammation may progress to HCC. The large hepatitis D antigen is a regulator of various cellular functions and an activator of signal transducer and activator of transcription (STAT)3 and the nuclear factor kappa B pathway. Another proposed epigenetic mechanism by which HCC may form is the aberrant silencing of tumor suppressor genes by DNA Methyltransferases. HDV antigens have also been associated with increased histone H3 acetylation of the clusterin promoter. This enhances the expression of clusterin in infected cells, increasing cell survival potential. Any contribution of HBV DNA integration with chromosomes of infected hepatocytes is not clear at this stage. The targeted inhibition of STAT3 and cyclophilin, and augmentation of peroxisome proliferator-activated receptor γ have a potential therapeutic role in HCC.

Population-attributable fractions of risk factors for hepatocellular carcinoma in the United States

OBJECTIVES

Risk factors for hepatocellular carcinoma (HCC) include hepatitis B and C viruses (HBV, HCV), excessive alcohol consumption, rare genetic disorders and diabetes/obesity. The population attributable fractions (PAF) of these factors, however, have not been investigated in population-based studies in the United States.

METHODS

Persons ≥68 years diagnosed with HCC (n=6,991) between 1994 and 2007 were identified in the SEER-Medicare database. A 5% random sample (n=255,702) of persons residing in SEER locations were selected for comparison. For each risk factor, odds ratios (ORs), 95% confidence intervals (95% CI) and PAFs were calculated.

RESULTS

As anticipated, the risk of HCC was increased in relationship to each factor: HCV (OR 39.89, 95% CI: 36.29-43.84), HBV (OR 11.17, 95% CI: 9.18-13.59), alcohol-related disorders (OR 4.06, 95% CI: 3.82-4.32), rare metabolic disorders (OR 3.45, 95% CI: 2.97-4.02), and diabetes and/or obesity (OR 2.47, 95% CI: 2.34-2.61). The PAF of all factors combined was 64.5% (males 65.6%; females 62.2%). The PAF was highest among Asians (70.1%) and lowest among black persons (52.4%). Among individual factors, diabetes/obesity had the greatest PAF (36.6%), followed by alcohol-related disorders (23.5%), HCV (22.4%), HBV (6.3%) and rare genetic disorders (3.2%). While diabetes/obesity had the greatest PAF among both males (36.4%) and females (36.7%), alcohol-related disorders had the second greatest PAF among males (27.8%) and HCV the second greatest among females (28.1%). Diabetes/obesity had the greatest PAF among whites (38.9%) and Hispanics (38.1%), while HCV had the greatest PAF among Asians (35.4%) and blacks (34.9%). The second greatest PAF was alcohol-related disorders in whites (25.6%), Hispanics (30.1%) and blacks (and 18.5%) and HBV in Asians (28.5%).

CONCLUSIONS

The dominant risk factors for HCC in the United States among persons ≥68 years differ by sex and race/ethnicity. Overall, eliminating diabetes/obesity could reduce the incidence of HCC more than the elimination of any other factor.

Coalescent inference for infectious disease: meta-analysis of hepatitis C

Genetic analysis of pathogen genomes is a powerful approach to investigating the population dynamics and epidemic history of infectious diseases. However, the theoretical underpinnings of the most widely used, coalescent methods have been questioned, casting doubt on their interpretation. The aim of this study is to develop robust population genetic inference for compartmental models in epidemiology. Using a general approach based on the theory of metapopulations, we derive coalescent models under susceptible–infectious (SI), susceptible–infectious–susceptible (SIS) and susceptible–infectious–recovered (SIR) dynamics. We show that exponential and logistic growth models are equivalent to SI and SIS models, respectively, when co-infection is negligible. Implementing SI, SIS and SIR models in BEAST, we conduct a meta-analysis of hepatitis C epidemics, and show that we can directly estimate the basic reproductive number (R₀) and prevalence under SIR dynamics. We find that differences in genetic diversity between epidemics can be explained by differences in underlying epidemiology (age of the epidemic and local population density) and viral subtype. Model comparison reveals SIR dynamics in three globally restricted epidemics, but most are better fit by the simpler SI dynamics. In summary, metapopulation models provide a general and practical framework for integrating epidemiology and population genetics for the purposes of joint inference.

Status quo of chronic liver diseases, including hepatocellular carcinoma, in Mongolia

Because Mongolia has much higher liver disease burden than any other regions of the world, it is necessary to provide information on real-time situation of chronic liver disease in Mongolia. In this article, we reviewed studies performed in Mongolia from 2000 to 2011 on seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) among healthy individuals and patients with chronic liver diseases, and on the practice patterns for the management of liver cirrhosis and hepatocellular carcinoma (HCC). According to previous reports, the seroprevalence of HBV and HCV in general population in Mongolia is very high (11.8% and 15% for HBV and HCV, respectively). Liver cirrhosis is also highly prevalent, and mortality from liver cirrhosis remained high for the past decade (about 30 deaths per 100,000 populations per year). Among patients with cirrhosis, 40% and 39% are positive for HBsAg and anti-HCV, respectively, and 20% are positive for both. The seroprevalence is similar for HCC and more than 90% of HCC patients are positive for either HBV or HCV. The incidence of HCC in Mongolia is currently among the highest in the world. The mortality from HCC is also very high (52.2 deaths per 100,000 persons per year in 2010). Partly due to the lack of established surveillance systems, most cases of HCC are diagnosed at an advanced stage. The mortality from liver cirrhosis and HCC in Mongolia may be reduced by implementation of antiviral therapy program and control of alcohol consumption.

Current hepatitis delta virus type 1 (HDV1) infections in central and eastern Turkey indicate a wide genetic diversity that is probably linked to different HDV1 origins

Hepatitis delta virus (HDV) is a subviral pathogen of humans, a satellite of hepatitis B virus (HBV) that induces severe acute and chronic liver diseases. The genus Deltavirus consists of eight clades or genotypes, with HDV1 being ubiquitous and frequently characterized. In Turkey, HDV1 infection is highly endemic among HBsAg carriers, especially in the southeastern region. In this study, we analyzed 34 samples from patients who were chronically infected with HBV/HDV, originating from 22 cities of rural regions in the central and eastern parts of Turkey, in order to determine the levels of viral replication and genetic diversity. HDV RNA levels ranged between 3.02 and 8.75 Log copies/mL, and HBV DNA was detected in 25 samples (73.5%), with values ranging from 2.53 to 5.30 Log copies/mL. Analysis of nucleotides 900-1280 of HDV genomes (n = 34) and full-length (n = 17) sequences indicated that all of the strains belonged to genotype HDV1. However, a high genetic diversity was observed among the isolates, with a mean full-length dissimilarity score of 13.05%. HDV sequences clustered with sequences from Western Europe (n = 11), Eastern Europe and Asia (n = 19) or Africa (n = 4). HDV1 isolates related to strains of African origin had a serine residue instead of an alanine at position 202 of the large delta protein. HBV preS1 sequences obtained for 34 isolates indicated an HBV/D genotype in all cases. Taken together, our results indicate that in Turkey, where HBV-HDV dual infection is highly endemic, both viruses have high levels of replication, and HDV strains exhibit wide genetic diversity, which might reflect ancient evolution and/or successive outbreaks.

An overview of triple infection with hepatitis B, C and D viruses

Viral hepatitis is one of the major health problems worldwide, particularly in South East Asian countries including Pakistan where hepatitis C virus (HCV) and hepatitis B virus (HBV) infections are highly endemic. Hepatitis delta virus (HDV) is also not uncommon world-wide. HCV, HBV, and HDV share parallel routes of transmission due to which dual or triple viral infection can occur in a proportion of patients at the same time. HBV and HCV are important factors in the development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). In addition to LC and HCC, chronic HDV infection also plays an important role in liver damage with oncogenic potential.

The current article reviews the available literature about the epidemiology, pathogenesis, transmission, symptoms, diagnosis, replication, disease outcome, treatment and preventive measures of triple hepatitis infection by using key words; epidemiology of triple infection, risk factors, awareness status, treatment and replication cycle in PubMed, PakMediNet, Directory of Open Access Journals (DOAJ) and Google Scholar. Total data from 74 different studies published from 1983 to 2010 on triple hepatitis infections were reviewed and included in this study. The present article briefly describes triple infection with HCV, HBV and HDV.

Viral phylodynamics and the search for an 'effective number of infections'

Information on the dynamics of the effective population size over time can be obtained from the analysis of phylogenies, through the application of time-varying coalescent models. This approach has been used to study the dynamics of many different viruses, and has demonstrated a wide variety of patterns, which have been interpreted in the context of changes over time in the ‘effective number of infections’, a quantity proportional to the number of infected individuals. However, for infectious diseases, the rate of coalescence is driven primarily by new transmissions i.e. the incidence, and only indirectly by the number of infected individuals through sampling effects. Using commonly used epidemiological models, we show that the coalescence rate may indeed reflect the number of infected individuals during the initial phase of exponential growth when time is scaled by infectivity, but in general, a single change in time scale cannot be used to estimate the number of infected individuals. This has important implications when integrating phylogenetic data in the context of other epidemiological data.

Chronic hepatitis C increased the mortality rates of patients with hepatocellular carcinoma and diabetes mellitus in a triple hepatitis virus endemic community

BACKGROUND

To elucidate the factors associated with mortality rates among older subjects with hepatocellular carcinoma (HCC) and diabetes mellitus (DM) in a triple hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis delta virus (HDV) endemic community.

METHODS

A total of 2,909 residents aged>or=45 years were screened for hepatitis B surface antigen (HBsAg), antibodies to HCV (anti-HCV) and alanine aminotransaminase (ALT) in 1997. Anti-HDV was detected in HBsAg-positive subjects. Those who expired from HCC and DM were identified from official mortality data sets (1997-2003). Survival was analyzed using the Kaplan-Meier survival curve with log-rank test and the Cox proportional hazard model.

RESULTS

Forty-one patients died of HCC and 25 of DM during the study period. Multivariate analysis indicated that age>or=65 years (hazard ratio 3.4; 95% confidence interval 1.8-6.4), HBsAg (3.3; 1.7-6.7), anti-HCV (3.8; 1.7-8.5) and ALT>or=40 IU/L (3.7; 1.9-7.0) were independent predictors of HCC mortality, while age>or=65 years (4.8; 2.1-11.0) and anti-HCV (4.2; 1.7-10.6) were two independent predictors of DM mortality. There were synergistic effects of dual viral infections for HCC, but not for DM mortality.

CONCLUSIONS

Old age and chronic HCV infection increase the risk of HCC and DM mortality. HBsAg and ALT levels are also risk factors for HCC mortality, but not DM. The synergistic effects of dual hepatitis viral infections are demonstrable and warrant further investigation.

A model of interaction: aflatoxins and hepatitis viruses in liver cancer aetiology and prevention

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and has an extremely poor prognosis. The majority of cases occur in south-east Asia and sub-Saharan Africa where the major risk factors are chronic infection with hepatitis B and C viruses (HBV and HCV) as well as dietary exposure to aflatoxins. Aflatoxin B1, the most commonly occurring and potent of the aflatoxins is associated with a specific AGG to AGT transversion mutation at codon 249 of the p53 gene in human HCC, providing mechanistic support to a causal link between exposure and disease. Prospective epidemiological studies have shown a more than multiplicative interaction between HBV and aflatoxins in terms of HCC risk. However, the biology underlying this statistical interaction is not fully understood. There are a number of potential mechanisms including, among others: the fixation of AFB1-induced mutations in the presence of liver regeneration and hyperplasia induced by chronic HBV infection; the predisposition of HBV-infected hepatocytes to aflatoxin-induced DNA damage; an increase in susceptibility to chronic HBV infection in aflatoxin-exposed individuals; and oxidative stress exacerbated by co-exposure to aflatoxins and chronic hepatitis infection. Priorities for prevention are global HBV vaccination, primary and secondary prevention strategies against aflatoxin and the avoidance of transmission of HCV through good hygiene practices.

Epidemiological and clinical evaluation of hepatitis B, hepatitis C, and delta hepatitis viruses in Tajikistan

The implication of genotypes is recognized increasingly in the clinical course of hepatitis B virus (HBV) and in response to anti-viral drugs of hepatitis C virus (HCV). Genotypic prevalence of both etiological agents varies geographically and no data are available for Tajikistan. To investigate the epidemiology and clinical significance of HBV and HCV genotypes in chronic hepatitis (group 1) and liver cirrhosis/hepatocellular carcinoma (HCC) (group 2) patients in Tajikistan, 124 patients with chronic liver disease (group 1 = 84 and group 2 = 40) were enrolled. Genotypes of HBV, HCV, and delta hepatitis virus (HDV) were determined by sequencing. The overall prevalence of anti-HCV, HCV core antigen (HCVcAg) and HBsAg was 46% (57/124) and 41.1% (51/124), respectively. Coinfection of HCV/HBV, HBV/HDV, and HCV/HBV/HDV was found in 4.8% (6/124), 11.2% (12/124), and 0.8% (1/124) of cases, respectively. HDV genotype 1 was found in 19.6% (10/51) of HBsAg-positive patients. The HBV/HDV coinfection was relatively high in group 2 compared to group 1 (15% vs. 7.1%). HCV/1b detected in 84.6% (44/52) of HCV RNA-positive patients, followed by 3a (7.6%), 2a (5.7%), and 2c (1.9%). HBV/D was detected in 94.1% (48/51) of HBsAg-positive patients, followed by HBV/A [5.8% (3/51)]. T1762/A1764 double mutation was associated with liver cirrhosis/HCC in HBV-infected patients (P = 0.0004). This is the first study on the molecular epidemiology of hepatitis viruses among chronic liver diseases patients in Tajikistan. Among HBV-infected patients, the T1762/A1764 mutation was associated with liver cirrhosis/HCC.