Common genotypes of Hepatitis B virus prevalent in injecting drug abusers (addicts) of North West Frontier Province of Pakistan

Phylogenetic Analysis and Emerging Drug Resistance against Different Nucleoside Analogues in Hepatitis B Virus Positive Patients

Several nucleotide analogues have been approved for use in treating hepatitis B virus (HBV) infection. Long-term exposure to therapy leads to the emergence of mutations within the HBV DNA polymerase gene, resulting in drug resistance, a major factor contributing to therapy failure. Chronic HBV patients from the Khyber Pakhtunkhwa province, Pakistan, who had completed 6 months of therapy participated in this study. Samples were collected from 60 patients. In this study, the entire reverse transcriptase domain of the HBV polymerase gene was amplified using nested polymerase chain reaction and sequenced. Drug-resistant mutations were detected in nine (22.5%) patients. All of these patients had lamivudine-resistant mutations (rtM204V + L180M), while seven individuals (17.5%) had both lamivudine- plus entecavir-resistant mutations (L180M + M204V + S202G). N236T, a mutation that gives rise to tenofovir and adefovir resistance, was observed in two (5%) patients. T184A, a partial drug-resistant mutation to entecavir, was found in five (12.5%) patients. Furthermore, other genotypic variants (100%) and vaccine escape mutations (5%) were additionally observed. Moreover, pN459Y (35%), pN131D (20%), pL231S (20%), pP130Q (17.5%), pS189Q (12.5%), pP161S (5%), pH160P (2.5%), pT322S (2.5%), and pA223S (2.5%) mutations in the polymerase gene, as well as sA166V (17.5%), sQ181K (12.5%), sV184R (7.5%), sA17E (5%), sP153S/K (5%), sW156C (5%), sC76Y (2.5%), and S132F (2.5%) mutations in the small surface gene, were identified for the first time in this study. Phylogenetic analysis showed that genotype D was predominant amongst the HBV carriers. Subtype D1 was found in most patients, while two patients were subtype D9. These novel findings may contribute to the body of knowledge and have clinical significance for treating and curing HBV infections in Pakistan.

A Recent Prevalence of Hepatitis B Virus (HBV) Genotypes and Subtypes in Asia: A Systematic Review and Meta-Analysis

Background and Aim: Despite introducing the hepatitis B virus (HBV) vaccine, the incidence of the Hepatitis B virus globally is still a major health concern. This systematic review and meta-analysis were conducted to provide detailed information on the prevalence of HBV genotypes and subtypes in circulation in Asia. Methods: A systematic search for articles describing the prevalence of HBV genotypes and subtypes in Asia was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Results: Our search returned 207 eligible articles involving 49,279 genotypes and 7457 subtypes representing 28 Asian countries. A meta-analysis was performed on our eligible studies using the Random effect Model. The pooled prevalence of HBV genotypes showed that genotype C (30.9%) (95% CI, 27.5–34.5%; I2 = 97.57%; p < 0.001) was the most common HBV genotype in Asia, followed by genotype B (17.8%) (95% CI, 15.5–20.4%; I2 = 97.26%; p < 0.001) and genotype D (15.4%) (95% CI, 11.8–19.8%). Vietnam had the highest prevalence of genotype B, Lebanon had the highest prevalence of genotypes C, and Jordan had the highest prevalence of genotype D. There was variation in genotypic prevalence with respect to the target genes for HBV genotyping. Reverse dot blot hybridization had the highest estimate of genotypes B and C. HBV subtype C2 (40.0%) (95% CI, 33.3–47.0) is the most prevalent HBV subtype. Conclusion: Evidence from this study reveals that HBV genotypes C and B are the most dominant HBV genotypes in Asia, and HBV subtype C2 is more endemic in Asia.

Associations between the prevalence of chronic hepatitis B among people who inject drugs and country-level characteristics: An ecological analysis

INTRODUCTION

Globally, hepatitis B virus (HBV) is a leading cause of liver disease. People who inject drugs (PWID) are at greater risk than the general population of contracting HBV. This risk could depend on societal factors in different countries. We investigated the associations between country-level chronic HBV prevalence in PWID with national indicators of development and prevalence of HIV and hepatitis C virus (HCV).

METHODS

We used global systematic review data on chronic HBV prevalence (hepatitis B surface antigen-positive) among PWID and country-level sociodemographic characteristics from online databases. National random-effects meta-analysis estimates of HBV prevalence were the outcome in linear regression models testing for associations with country-level characteristics.

RESULTS

The study included 131,710 PWID from 304 estimates in 55 countries: the pooled HBV prevalence among PWID in the countries analysed was 4.5% (95% CI 3.9-5.1), the highest regional pooled prevalence was in East and Southeast Asia (17.6% [13.3-22.3]), and the lowest was in Western Europe (1.7% [1.4-2.1]). In multivariable models, no indicators of development were associated with HBV prevalence, but there was evidence of positive associations between HBV prevalence in the general population and among PWID, and evidence of HIV and HCV prevalence in PWID being associated with HBV prevalence in PWID: multivariable coefficients 0.03 (95% CI 0.01-0.04); p < 0.001, and 0.01 (95% CI 0.00-0.03); p = 0.01, respectively.

DISCUSSION AND CONCLUSIONS

HBV prevalence among PWID was associated with HIV and HCV prevalence among PWID and background HBV prevalence in the general population, highlighting the need for improving harm reduction in PWID and implementation of HBV vaccination, especially where HBV is endemic.

Seroprevalence and Factors Associated with Risk of Hepatitis B Virus Infection among Antenatal Attendees in ABUTH Zaria, Northwestern Nigeria

Background

Nigeria is one of the sub-Saharan African countries within the World Health Organization's (WHO) hyperendemic region for hepatitis B virus infection with prevalence greater than 8%. In this region, mother-to-child transmission is the major route of infection and approximately 90% of newborns of mothers who are seropositive for HBsAg and HBeAg become chronic carriers with a 25% risk of developing chronic liver diseases. This study aimed to determine the seroprevalence, and factors associated with risk of hepatitis B virus infection among antenatal attendees in Ahmadu Bello University Teaching Hospital (ABUTH), Zaria.

Methodology

A hospital based cross sectional study was conducted among pregnant women Rattending the antenatal booking clinic of ABUTH, Zaria from August 2017 to January 2018. Systematic random sampling was used. An interviewer administered questionnaire was used to obtain data on sociodemographic characteristics and risk factors for HBV infection. Blood samples were collected and tested using the third generation ELISAkit for HBsAg (Monolisa HBsAg ULTRA BIORAD, France) and HBeAg(HBeAg & Ab, DiaPro Diagnostic Bioprobes Milano Italy). Data were analyzed using SPSS version 20 (IBM USA, 2011). Statistical testing was carried out with chi-squareand level of significance set as P<0.05.

Results

The mean age of the respondents was 26 ± 6.1 years, the highest HBV seropositivity occurred in the age group 21-25 years from a total of 192 participants. The seroprevalence of HBV obtained was 15.1%. Only1(3.4%) woman was positive for HBeAg among the 29 HBsAg seropositive women. Past history of unsafe injections was the only risk factor significantly associated with HBV seropositivity (x2= 5.628 p-value= 0.023).

Conclusions

The seropositivity of hepatitis B virus was high among pregnant women. Interventions targeted at injection safety will help reduce the risk of infection.

Seroepidemiology and associated risk factors of hepatitis B and C virus infections among pregnant women attending maternity wards at two hospitals in Swabi, Khyber Pakhtunkhwa, Pakistan

BACKGROUND & AIM

Hepatitis B and C infections are global issues that are associated with a massive financial burden in developing countries where vertical transmission is the major mode and remains high. This cross-sectional study was designed to investigate the seroepidemiology and associated risk factors of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among 375 pregnant women attending antenatal care health facilities at Bacha Khan Medical Complex (BKMC) Shahmansoor and District Head Quarter (DHQ) Hospital Swabi, Khyber Pakhtunkhwa, Pakistan.

METHODOLOGY

From a total of 375 pregnant women selected using systematic random sampling from both hospitals, 10 ml of blood samples were collected and alienated serum was examined for indicators identification through the Immuno-Chromatographic Test (ICT) and 3rd Generation Enzyme-Linked Immunosorbent Assay (ELISA). A pre-structured questionnaire was used to collect the socio-demographic data and possible risk factors. The data was analyzed via SPSS 23.0 statistical software. A chi-square analysis was performed to determine the association between variables. P-value < 0.05 was set statistically significant.

RESULTS

The overall frequency of HBV and HCV among 375 pregnant women involved in the study was 3.7% and 2.1% respectively. None of the pregnant women were co-infected with HBV and HCV. Dental extraction (P = 0.001) and blood transfusion (P = 0.0005) were significantly allied with HBV infection while surgical procedure (P = 0.0001) was significantly associated with HCV infection. Moreover the sociodemographic characteristics: residential status (P = 0.017) and educational level (P = 0.048) were found significant risk factors of HBsAg and maternal age (P = 0.033) of anti-HCV, respectively.

CONCLUSION & RECOMMENDATION

HBV and HCV infections are intermediary endemic in the study area. A higher prevalence of HBV was detected among pregnant mothers with a history of dental extraction, history of blood transfusion, resident to the urban area and low educational level. The age and surgical procedures were the potential risk factors found significantly associated with HCV positivity among pregnant mothers in our setup. Future negotiations to control vertical transmission should include routine antenatal screening for these infections early in pregnancy and the requirement of efficient preventive tools including the birth dose of the hepatitis B vaccine in combination with hepatitis B immune globulins to the neonate.

Epidemiological patterns and risk factors associated with hepatitis B virus in Pakistani population

Hepatitis B virus prevalence is increasing in Pakistani population. National level estimates regarding the prevalence are missing. People are unaware of the risk factors involved in HBV transmission. The objective of the study was to review the prevalence, genotypes, and risk factors associated with HBV transmission in Pakistani Population. Literature search was done by using keyword HBV prevalence, genotypes and risk factors from Pakistani population at Pubmed, PakMediNet and Google scholar. Six different studies showed that the percentage prevalence of HBV in general population was 4.61±0.73%, and 21 different studies showed the percentage prevalence of 2.33±0.46% in blood donors. High prevalence of 7.94±1.49% and 12.86±4.52% were observed in multi transfused and IDU populations. Six different studies showed that the major prevalent genotype was D. Awareness regarding various risk factors involved in-viral transmission was very low. Prevalence of HBV was very high in multitransfused populations due to non-implementations of international standards regarding blood transfusions. Barbers were unaware of the risk factors associated with their shops in viral transmission. Practices of unsterilized dental and surgical instruments and recycling of syringes were major factors in viral transmission. Massive awareness and vaccination programs are required to decrease the future burden of HBV from Pakistani population.

Determining the Actual Prevalence of Hepatitis B in Khyber Pakhtunkhwa-Pakistan: A Meta-Analysis

Background:

Hepatitis B is considered the most dangerous among the five types of Hepatitis, as it is clinically asymptomatic. It can silently damage the liver over many years without being diagnosed. Hepatitis B is one of the top risks of liver complications in Khyber Pakhtunkhwa (KP), a province of Pakistan, with an average prevalence rate of 2.70%.

Aims:

We aimed to carefully review the previously published data on prevalence of Hepatitis B Virus (HBV) in KP-Pakistan and use the statistical approach to obtain more precise estimate of the prevalence of HBV in KP-Pakistan. This study on one hand will provide a more reliable and consolidated estimate (pooled estimate) of HBV in the stated region, on the other hand, it enabled us to judge the heterogeneity among the estimates found from these studies. The study is intended to provide more authentic prevalence record and help government/ non-government organizations and health professionals, which plan to initiate HBV prevention programs in KP-Pakistan.

Methods:

A meta-analysis was performed based on studies found in literature search from electronic databases and bibliography on the prevalence of HBV in KP-Pakistan from 2007 to 2017. Abstracts and results of twenty papers were thoroughly studied and the data were extracted. The findings from these studies were distributed in two groups (general and population at high risk) constituting 15 and 5 studies respectively.

Results:

The combined prevalence by considering random model for the general population of KP-Pakistan was observed to be 2.71%, while population at high risk was reasonably high i.e. 5.64%. By comparing this prevalence rate to the highest global prevalence of HBV in the adult population of Western Pacific Region (6.2%), significant (p-value= 0.000) heterogeneity was observed among the estimates in each group. However, the funnel plot provides a symmetric look, eliminating the effect of publication bias. We can say that HBV has an alarming prevalence rate in KP-Pakistan. However, HBV is thrice more prevalent in male population of KP-Pakistan than the female population.

Conclusion:

The above results lead that HBV infection has reached an alarming state in KP-Pakistan, though projects like Prime Minister’s Program for Prevention & Control of Hepatitis which are contributing in improving the health of the people of KP by trying to prevent and control the incidence of HBV. More massive vaccination and awareness programs should be initiated to prevent the spread of HBV on urgent basis. Provision of diagnostics and treatment facilities against HBV in healthcare units of KP-Pakistan should be assured.

Prevalence of mutations within major hydrophilic region of hepatitis B virus and their correlation with genotypes among chronically infected patients in Egypt

BACKGROUND AND STUDY AIMS

Mutations within the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) have been reported in relation to viral persistence by evasion from vaccine and immunotherapy, severity of liver disease and lack of detection by commercial kits. The aim of this study was to elucidate the circulation of hepatitis B virus (HBV) genotypes, subgenotypes and serotypes in Egypt, with recognition of the pattern and prevalence of MHR mutations possibly occurring during the course of the disease.

PATIENTS AND METHODS

Eighty-eight samples from patients with chronic HBV infection were included in the study. The surface protein-encoding gene (S gene) in the HBV genome was subjected to amplification and partial sequencing.

RESULTS

Based on phylogenetic analysis, only genotype D was found circulating among patients. The majority of isolates belonged to subgenotype D3 (86.3%), followed by D7 (8%), then D5 (3.4%) and lastly D1 (2.3%). Two subtypes were identified: ayw2 (97%) and ayw3 (2%). The 'w' sub-determinant was not defined in one isolate (1%). A significant proportion of patients (13/88, 14.8%) exhibited mutations in the MHR, 10 of whom harboured mutations in the 'a' determinant region and three outside. The first loop comprised four patients with three mutations (P127S, P127T and Y134F). The second loop contained six patients, all with one mutation, S143L, which was most frequently encountered in this study (6.8%).

CONCLUSIONS

We conclude that genotype D, subgenotype D3 and HBsAg subtype ayw2 are the most common types circulating in Egypt, which account for 100%, 86.3% and 97% of the population, respectively, with a moderate degree of MHR mutations.

Hepatitis B Virus Genotypes Distribution with HBsAg Positive in the North of Iran (Mazandaran) During 2011-2014

BACKGROUND

HBV infection is a major global health problem and ten genotypes (A to J) and multiples subtypes of HBV have been identified, and they show some distinct geographic distributions. The available data on HBV genotype in Iran are very heterogeneous and limited. Therefore in this study, we tried to identify the HBV genotypes by using polymerase chain reaction.

METHODS

In this cross-sectional study, HBV- positive serum samples of 122 patients with chronic hepatitis from 2011 to 2014 were studied. HBV-DNA was extracted from plasma samples using QIAamp(®) MiniElute(®) Virus Spin Kit (Qiagen). Plasma samples from HBsAg positive were confirmed the presence of HBV nucleic acid and determined the genotypes of HBV genome by PCR using the DNA PCR kit (Cinagene) with Taq-DNA polymerase enzyme and type of specific primers. All samples were examined in the virology laboratory of Sari Medical School.

RESULTS

The mean age of patients were 45 ± 25 (range, 20 to 70) year that 70 (57.37%) patients were male and 52 (42.62%) were female. The majority of HBV positive patients had a major surgery (44% patients) and then 32% patients followed by intra familial of hepatitis B virus infected and 11% of HBV positive patients had a history of blood transfusions. In this study, 91(74.59%) had genotype D, 7(5.73%) genotype B and 24(19.67%) genotype D and B.

CONCLUSION

This study indicates that the genotype D is the most frequent followed by the mixed genotypes D and B and genotype B in our region. Prevalence and incidence of HBV genotypes are with distributed among of areas and different genotypes may show different responses with antiviral therapy.

Prevalence and genotypes of hepatitis B virus infection in patients underwent coronary angiography and coronary artery bypass grafting in mazandaran heart center, sari, iran

BACKGROUND

Hepatitis B virus (HBV) infection is a major global health problem in the worldwide that associated with significant morbidity and mortality in cardiac surgery. The available data on HBV distribution and genotyping of HBV are very heterogeneous. Therefore in this study, we tried to indicate the prevalence of HBV infections in cardiac catheterization patients referred to health centers in the north of Iran and identified the HBV genotypes using polymerase chain reaction (PCR).

METHODS

In this cross-sectional study, we studied 2650 patients who underwent selective coronary artery angiography and coronary artery bypass grafting in Mazandaran heart center, Sari, Iran from 2011 to 2013. All serum samples were examined to detect HBsAg by ELISA test. HBV-DNA was extracted from HBsAg positive samples using Mini Elute Kit from Qiagen and determined the genotypes of HBV by PCR using the Master Mix kit with Taq-DNA polymerase enzyme and with type of specific primers. All samples were examined in the virology laboratory of Sari Medical School.

RESULTS

The mean age of patients was 59.7±10.9 (range, 20 to 81) year that 1590 (60%) patients were male and 1060 (40%) were female. Seventeen cases (0.08 %) were found with hepatitis B virus infection, and the highest rates of infection were reported among those aged 40-60 years old in this study. We found genotype D the predominant type in this study.

CONCLUSION

This study indicates that the prevalence of HBV endemicity in the north of Iran is low and genotype D is the only genotype in patients infected with HBV.

Occult hepatitis B virus infection among injecting drug users in the Central-West Region of Brazil

The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil's Central-West Region.

High prevalence of the B2+C2 subgenotype mixture in patients with chronic hepatitis B in Eastern China

AIM

To investigate the prevalence of hepatitis B virus (HBV) genotype mixtures among patients with chronic hepatitis B (CHB) in Eastern China.

METHODS

A total of 4908 chronic HBV patients from Eastern China were enrolled. HBV genotypes and subgenotypes were determined using a multiplex PCR technique. Serum viral loads and hepatitis B e antigen (HBeAg) levels detected using real-time fluorescent quantitative PCR and ELISA assay, respectively. The presence of precore/basic core promoter (PC/BCP) mutations was examined with PCR and direct sequencing of the amplified products.

RESULTS

HBV genotypes B, C, D, B+C, and B+D were found in 19.21%, 64.75%, 1.49%, 13.63%, and 0.92% of the patients, respectively. In 669 patients with the genotype mixture B+C, the subgenotypes B2+C2 and B2+C1 accounted for 68.13% and 31.87%, respectively, no other subgenotypes were identified. HBV B+C was more frequent in the patients with moderate CHB than in patients with mild CHB. In patients with moderate CHB, the subgenotype mixture B2+C2 was lower than B2+C1 (51.97% vs 63.38%), while the opposite situation was found in patients with severe CHB (22.15% vs 15.49%). The highest average viral load was found in patients with the genotype B+C mixture. The prevalence of HBV B2+C2 increased in patients from 50 to 59 years of age and was significantly different from the proportion of patients in the same age group with genotype B (23.2% vs 15.2%). A double mutation (G1896A) in the PC was significantly more common in subgenotype B2+C2 than in subgenotype B2+C1.

CONCLUSION

The HBV B2+C2 subgenotype was prevalent in CH patients with a high HBV replication status and correlated with a more severe course of the disease.

Hepatitis B virus in Pakistan: a systematic review of prevalence, risk factors, awareness status and genotypes

In Pakistan, there are estimated 7-9 million carriers of hepatitis B virus (HBV) with a carrier rate of 3-5%. This article reviews the available literature about the prevalence, risk factors, awareness status and genotypes of the HBV in Pakistan by using key words; HBV prevalence, risk factors, awareness status and genotypes in Pakistani population in PubMed, PakMediNet, Directory of Open Access Journals (DOAJ) and Google Scholar. One hundred and six different studies published from 1998 to 2010 were included in this study. Weighted mean and standard deviation were determined for each population group. The percentage of hepatitis B virus infection in general population was 4.3318% ± 1.644%, healthy blood donors (3.93% ± 1.58%), military recruits (4.276% ± 1.646%), healthcare persons (3.25% ± 1.202%), pregnant women (5.872% ± 4.984), prisoners (5.75% ± 0.212%), surgical patients (7.397% ± 2.012%), patients with cirrhosis (28.87% ± 11.90%), patients with HCC (22% ± 2.645%), patients with hepatitis (15.896% ± 14.824%), patients with liver diseases (27.54% ± 6.385%), multiple transfused patients (6.223% ± 2.121%), opthalmic patients (3.89% ± 1.004%) and users of injectable drugs (14.95% ± 10.536%). Genotype D (63.71%) is the most prevalent genotype in Pakistani population. Mass vaccination and awareness programs should be initiated on urgent basis especially in populations with HBV infection rates of more than 5%.

An overview of treatment response rates to various anti-viral drugs in Pakistani hepatitis B virus infected patients

Hepatitis B virus (HBV) is one of the leading health problem with up to 350 million affected people worldwide including 4.5 million only in Pakistan. It has mortality rate of 0.5 to 1.2 million per year worldwide. Pakistan lies in the endemic region with 3-5% HBV carrier rate in the country. The present article reviews the literature on the treatment response of HBV prevalent in Pakistani population. The average treatment response of Lamivudine and interferon-α is 25.81% and 47.95%, respectively. Peg-Interferon was shown to be not effective against the HBV/HCV (hepatitis C virus)/HDV (hepatitis Delta virus) co-infection. The present study reveals that interferon-α is the most effective therapy available for HBV infection prevalent in Pakistani population. Genotype C & D are the most common HBV genotypes in Pakistan and are associated with increased severity and less response to interferon therapy. This poses a great challenge for physicians and researchers and further studies are needed to describe the outcome of the current therapies recommended against HBV infection in Pakistani population.

Geographical and genetic diversity of the human hepatitis B virus

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.

Hepatitis B virus genotypes, subgenotypes, precore, and basal core promoter mutations in the two largest provinces of Pakistan

BACKGROUND AND AIM

Hepatitis B virus (HBV) genotyping has been done in most countries, but unfortunately, in Pakistan, HBV genotypic distribution is still unclear. The aim of the present study was to determine the prevalent genotype and subgenotype in the two most populated provinces in Pakistan: Punjab and Sind.

METHODS

In total, 236 HBV DNA-positive samples were selected for genotyping by polymerase chain reaction-restriction fragment length polymorphism (RFLP). The RFLP results were further confirmed with whole genome and partial genome sequencing.

RESULTS

Genotype D was detected as the most prevalent (93.22%) genotype in all eight cities of both provinces; genotype C was present in 5.93% and genotype A was present in 0.85% of the samples. The D1 subtype was present in 84%, and D2 was present in 8% of 25 whole genome-sequenced samples. The C2 subtype was detected in 58.33% of S gene-sequenced samples, while D1 was detected in the remaining 41.67% of 24 samples sequenced for the S gene. Subtype D1 is the most dominant in D, while C2 is dominant in genotype C. Eight- and 15-bp deletion mutations were also detected in genotype D samples. Other precore and basal core promoter (BCP) mutations included T1915 (100%), A1679 (86.96%), T1762 (39.13%), and A1764 (30.43%), which were also detected in the genotype D samples.

CONCLUSION

Genotype D subtype D1 is the most prevalent HBV strain in Pakistan with 8-bp deletion mutants the most common in HBV carriers.

Hepatitis B virus subgenotypes D1 and D3 are prevalent in Pakistan

Background

As the hepatitis B genotyping is important for assessing its clinical implications and geographical distribution, the sub-genotypes have been found useful for determination of specific genomic markers related to hepatocarcinogenesis. In Pakistan, there is no reported data on molecular evolutionary analysis of HBV. A study was, therefore, much needed to evaluate the spectra of mutations present in the strains prevalent here.

Findings

to confirm specificity of PCR typing, phylogenetic analysis of the pre-S1 region and the divergence was studied through 13 sequences of 362 bp (accession number EF432765 – EF432777). A total of 315 serum samples, selected from HBsAg positive patients representing the major ethnic groups, residing in Karachi, Sindh were tested for genotyping. Genotype D (219/315) was found to be the most prevalent (70%) amongst our patients. The rest of the genotypes A and a mixture of A and D (AD) were distributed as 20%, and 10% respectively. Phylogenetic tree demonstrated clustering of 11 samples with subgenotype D1 sequences and the remaining two strains on a branch within D3 samples. All samples intermixed with strains from other countries and were found to be closely related to Indian, Iranian and Egyptian HBV strains with 98.7 – 99.0% homology.

Conclusion

This study confirms the predominance of genotype D in southeastern Asia and presence of subgenotypes DI and D3 in the Pakistani infected patients. More studies are required to investigate the reason for fewer inclusions of D3 compared to the D1 in Pakistani HBV strains.

Genotype D amongst injection drug users with acute hepatitis B virus infection in British Columbia

The eight genotypes of hepatitis B virus (HBV) exhibit distinct geographical distributions. This study identified HBV genotypes and transmission modes associated with acute infection in British Columbia (BC), Canada, from 2001 to 2005. Seventy cases of acute HBV in BC were identified from laboratory reports using a standardized case definition. Interviews for risk factors and hepatitis history were conducted for each case. HBV genotypes were determined by BLAST comparison analysis of the surface (S) or preS gene sequence. To illustrate the distribution of genotypes identified amongst acute cases in BC, an annotated map was produced showing the global occurrence of HBV genotypes. The majority of acute HBV cases occurred in Caucasian, Canadian-born males, with 30% of cases reporting injection drug use (IDU) and 21% reporting incarceration. The most common genotype observed was genotype D (62.9%), followed by genotypes A (18.6%), C (11.4%), B (4.3%), and E (1.4%). A significant association was observed between Genotype D and IDU (P = 0.0025) and previous incarceration (P = 0.0067). Phylogenetic analysis of the S gene sequence demonstrated identical or high genetic relatedness amongst genotype D viral strains (86% sub-genotype D3), thus verifying transmission clustering amongst BC injection drug users. The association between acute HBV genotype and reported transmission modes has not been previously described in North America. Tracking of genotypes can help identify disease transmission patterns and target at-risk populations for preventive immunization.

Two simultaneous hepatitis B virus epidemics among injecting drug users and men who have sex with men in Buenos Aires, Argentina: characterization of the first D/A recombinant from the American continent

Previous studies have revealed that hepatitis B virus (HBV)/D and HBV/F predominate among blood donors from Buenos Aires, Argentina. In the present study, blood samples from two high-risk groups were analysed: 160 corresponding to street- and hospital-recruited injecting drug users [81.2% showing the 'anti-hepatitis B core antigen (anti-HBc) only' serological pattern] and 20 to hepatitis B surface antigen (HBsAg)(+)/anti-HBc(+) men who have sex with men. HBV genotypes were assigned by polymerase chain reaction amplification followed by restriction fragment length polymorphism and confirmed by nucleotide sequencing of two different coding regions. HBV DNA was detected in 27 injecting drug users (16.9%, occult infection prevalence: 7.7%), and 14 men who have sex with men (70%). HBV/A prevailed among injecting drug users (81.8%) while HBV/F was predominant among men who have sex with men (57.1%). The high predominance of HBV/A among injecting drug users is in sharp contrast to its low prevalence among blood donors (P = 0.0006) and men who have sex with men (P = 0.0137). Interestingly, all HBV/A S gene sequences obtained from street-recruited injecting drug users encoded the rare serotype ayw1 and failed to cluster within any of the known A subgenotypes. Moreover, one of the HBV strains from a hospital-recruited injecting drug user was fully sequenced and found to be the first completely characterized D/A recombinant genome from the American continent. Data suggest that two simultaneous and independent HBV epidemics took place in Buenos Aires: one spreading among injecting drug users and another one sexually transmitted among the homosexual and heterosexual population.

The association of complex liver disorders with HBV genotypes prevalent in Pakistan

Background

Genotyping of HBV is generally used for determining the epidemiological relationship between various virus strains and origin of infection mostly in research studies. The utility of genotyping for clinical applications is only beginning to gain importance. Whether HBV genotyping will constitute part of the clinical evaluation of Hepatitis B patients depends largely on the availability of the relevance of the evidence based information. Since Pakistan has a HBV genotype distribution which has been considered less virulent as investigated by earlier studies from south East Asian countries, a study on correlation between HBV genotypes and risk of progression to further complex hepatic infection was much needed

Methods

A total of 295 patients with HBsAg positive were selected from the Pakistan Medical Research Council's (PMRC) out patient clinics. Two hundred and twenty six (77%) were males, sixty nine (23%) were females (M to F ratio 3.3:1).

Results

Out of 295 patients, 156 (53.2%) had Acute(CAH), 71 (24.2%) were HBV Carriers, 54 (18.4%) had Chronic liver disease (CLD) Hepatitis. 14 (4.7%) were Cirrhosis and HCC patients. Genotype D was the most prevalent genotype in all categories of HBV patients, Acute (108), Chronic (39), and Carrier (53).

Cirrhosis/HCC (7) were HBV/D positive. Genotype A was the second most prevalent with 28 (13%) in acute cases, 12 (22.2%) in chronics, 14 (19.7%) in carriers and 5 (41.7) in Cirrhosis/HCC patients. Mixed genotype (A/D) was found in 20 (12.8%) of Acute patients, 3 (5.6%) of Chronic and 4 (5.6%) of carriers, none in case of severe liver conditions.

Conclusion

Mixed HBV genotypes A, D and A/D combination were present in all categories of patients except that no A/D combination was detected in severe conditions. Genotype D was the dominant genotype. However, genotype A was found to be more strongly associated with severe liver disease. Mixed genotype (A/D) did not significantly appear to influence the clinical outcome.