Outbreak of Hepatitis B among injecting drug users in Denmark

Hepatitis C time trends in reported cases and estimates of the hidden population born before 1965, Denmark and Sweden, 1990 to 2020

BackgroundAccording to the World Health Organization, hepatitis C virus (HCV) infection should be under control by 2030.AimOur aim was to describe the size and temporal changes in reported cases of chronic HCV infection in Denmark and Sweden and to estimate the size of the hidden (undiagnosed) population born before 1965.MethodsWe extracted all HCV infections reported to national surveillance systems in Denmark and Sweden from 1990 to 2020. Prediction of the size of the hidden HCV-infected population was restricted to the cohort born before 1965 and cases reported up to 2017. We applied a model based on removal sampling from binomial distributions, estimated the yearly probability of diagnosis, and deducted the original HCV-infected population size.ResultsDenmark (clinician-based) reported 10 times fewer hepatitis C cases annually than Sweden (laboratory and clinician-based), peaking in 2007 (n = 425) and 1992 (n = 4,537), respectively. In Denmark, the birth year distribution was monophasic with little change over time. In recent years, Sweden has had a bimodal birth year distribution, suggesting ongoing infection in the young population. In 2017, the total HCV-infected population born before 1965 was estimated at 10,737 living persons (95% confidence interval (CI): 9,744-11,806), including 5,054 undiagnosed, in Denmark and 16,124 (95% CI: 13,639-18,978), including 10,580 undiagnosed, in Sweden.ConclusionsThe reporting of HCV cases in Denmark and Sweden was different. For Denmark, the estimated hidden population was larger than the current national estimate, whereas in Sweden the estimate was in line with the latest published numbers.

Deep sequencing of hepatitis B virus using Ion Torrent fusion primer method

BACKGROUND

Hepatitis B virus (HBV) infection is worldwide a major cause of liver cirrhosis and hepatocellular carcinoma. Thousands of years ago, several HBV genotypes (A-I) evolved and have, as a result of human migration, become globally disseminated. Sequencing of HBV is used for genotyping, and investigation of outbreaks or of antiviral resistance. The present study describes a simplified deep sequencing of the whole HBV genome.

METHODS

Sequencing by Ion Torrent was evaluated and its performance compared with Sanger sequencing on clinical samples.

RESULTS

Amplification of overlapping segments spanning the entire HBV genome was successful at HBV DNA levels in serum as low as 100 IU/mL. The use of primers carrying adapter tags generated libraries without the need for fragmentation and ligation steps, and inclusion of barcode sequences allowed parallel analysis of multiple samples. A streamlined bioinformatic platform generated consensus sequences and superior mutation assessment as compared with Sanger sequencing, with which there was a 99.8 % average agreement.

CONCLUSION

Deep sequencing of the whole HBV genome by using PCR primers tagged with adapters that prepare overlapping amplicons for Ion Torrent analysis was efficient and accurate.

Opioid epidemic and liver disease

Opioid use in the United States and in many parts of the world has reached epidemic proportions. This has led to excess mortality as well as significant changes in the epidemiology of liver disease. Herein, we review the impact of the opioid epidemic on liver disease, focusing on the multifaceted impact this epidemic has had on liver disease and liver transplantation. In particular, the opioid crisis has led to a significant shift in incident hepatitis C virus infection to younger populations and to women, leading to changes in screening recommendations. Less well characterized are the potential direct and indirect hepatotoxic effects of opioids, as well as the changes in the incidence of hepatitis B virus infection and alcohol abuse that are likely rising in this population as well. Finally, the opioid epidemic has led to a significant rise in the proportion of organ donors who died due to overdose. These donors have led to an overall increase in donor numbers, but also to new considerations about the better use of donors with perceived or actual risk of disease transmission, especially hepatitis C. Clearly, additional efforts are needed to combat the opioid epidemic. Moreover, better understanding of the epidemiology and underlying pathophysiology will help to identify and treat liver disease in this high-risk population.

A large proportion of people who inject drugs are susceptible to hepatitis B: Results from a bio-behavioural study in eight German cities

BACKGROUND

People who inject drugs (PWID) are at high risk of hepatitis B virus (HBV) infection by sharing needles and drug use paraphernalia. In Germany, no routine surveillance of HBV prevalence and vaccination coverage among PWID exists.

METHODS

Socio-demographic and behavioural data were collected between 2011 and 2014 through face-to-face interviews, during a bio-behavioural survey of PWID recruited in eight German cities. Dried blood spots (DBS) prepared with capillary blood were tested for HBV markers. Factors associated with past/current HBV infection and vaccination status were analysed by univariable and multivariable analysis using logistic regression. The validity of self-reported HBV infection and vaccination status was analysed by comparison to the laboratory results.

RESULTS

Among 2077 participants, the prevalence of current HBV infection was 1.1%, of past HBV infection was 24%, and of vaccine-induced HBV antibodies was 32%. No detectable HBV antibodies were found in 43%. HBV infection status was significantly associated with study city, age, years of injecting, use of stimulants, migration status, and homelessness; HBV vaccination status was significantly associated with study city, age, and level of education. Correct infection status was reported by 71% and correct vaccination status by 45%.

CONCLUSIONS

HBV seroprevalence among PWID was about five times higher than in the general population in Germany, confirming PWID as an important risk group. Targeted information campaigns on HBV and HBV prevention for PWID and professionals in contact with PWID need to be intensified. Routinely offered HBV vaccination during imprisonment and opioid substitution therapy would likely improve vaccination rates among PWID.

Epidemiology of HBV subgenotypes D

The natural history of hepatitis B virus infection is not uniform and affected from several factors including, HBV genotype. Genotype D is a widely distributed genotype. Among genotype D, several subgenotypes differentiate epidemiologically and probably clinically. D1 is predominant in Middle East and North Africa, and characterized by early HBeAg seroconversion and low viral load. D2 is seen in Albania, Turkey, Brazil, western India, Lebanon, and Serbia. D3 was reported from Serbia, western India, and Indonesia. It is a predominant subgenotype in injection drug use-related acute HBV infections in Europe and Canada. D4 is relatively rare and reported from Haiti, Russia and Baltic region, Brazil, Kenya, Morocco and Rwanda. Subgenotype D5 seems to be common in Eastern India. D6 has been reported as a rare subgenotype from Indonesia, Kenya, Russia and Baltic region. D7 is the main genotype in Morocco and Tunisia. D8 and D9 are recently described subgenotypes and reported from Niger and India, respectively. Subgenotypes of genotype D may have clinical and/or viral differences. More subgenotype studies are required to conclude on subgenotype and its clinical/viral characteristics.

Hepatitis B prevalence in Denmark - an estimate based on nationwide registers and a national screening programme, as on 31 December 2007

The prevalence of chronic hepatitis B virus (HBV) infection in Denmark is not clear. The primary aim of this study was to estimate the prevalence of chronic HBV infection in Denmark. The capture–recapture method was used to estimate the total population diagnosed with chronic HBV infection in Denmark using four nationwide registers. The population with undiagnosed chronic HBV infection was estimated by incorporating data from a two-year nationwide HBsAg screening programme in pregnant women. We identified 4,466 individuals with chronic HBV infection in the four registers until the end of 2007, and the capture–recapture estimate of the total population diagnosed with chronic hepatitis B was 7,112 (95% confidence interval (CI): 6,953–10,747). Only 17% of the identified patients attended recommended clinical care according to national guidelines. Including undiagnosed patients, the current population alive with HBV infection was 10,668 (95% CI: 10,224–16,164), corresponding to a prevalence of 0.24% (95% CI: 0.23–0.37%) in the Danish population older than 15 years. The estimated prevalence of chronic HBV infection among adults in Denmark was lower than reported from other northern European countries. Only half of the infected population had been diagnosed, and a minority attended specialised clinical care.

Genetic diversity of genotype D3 in acute hepatitis B

Acute hepatitis B related to injection drug use is often caused by HBV-D3, a subgenotype that probably was introduced in Western Europe in the 1960s. The aim of this study was to describe genetic change over time in injection drug use-related HBV-D3 in one geographic area. Fourteen complete genomes and partial genomic regions of 17 HBV strains of subgenotype D3 causing acute (n = 30) or chronic (n = 1) hepatitis B at different time points between 1975 and 2009 were investigated. The 14 complete genomes clustered in phylogenetic trees on a sub-branch of HBV-D3 along with a few published sequences with high bootstrap values. In contrast, the phylogenetic tree topology based on nucleotides coding for surface antigen or core was uncertain with bootstrap values below 70% or lower. Variation of nucleotides coding for amino acids 125, 136, and 143 in the a determinant of HBsAg was however linked to complete genome phylogeny, indicating that these codons might be useful as markers for clades. The results show that knowledge about circulating strains is critical for the interpretation of molecular epidemiology investigations. The low degree of genetic change over time of HBV-D3 in the studied groups suggests that outbreaks of acute hepatitis B in injection drug users might originate from a limited number of individuals with chronic infection. Classification based on core or S region phylogeny obtained poor support from bootstrap values, but the presence of clade-specific amino acid substitutions suggests that the S region may be useful for subgenomic molecular epidemiology of HBV.

Hepatitis C prevalence in Denmark -an estimate based on multiple national registers

BACKGROUND

A national survey for chronic hepatitis C has not been performed in Denmark and the prevalence is unknown. Our aim was to estimate the prevalence of chronic hepatitis C from public registers and the proportion of these patients who received specialized healthcare.

METHODS

Patients with a diagnosis of chronic hepatitis C were identified from four national registers: a laboratory register, the Hospital Discharge Register, a clinical database of chronic viral hepatitis and the Register of Communicable Diseases. The total population diagnosed with hepatitis C was estimated by capture-recapture analysis. The population with undiagnosed hepatitis C was derived from the national register of drug users by comparing diagnosed and tested persons.

RESULTS

A total of 6,935 patients diagnosed with chronic hepatitis C were identified in the four registers and the estimated population diagnosed with the disease was 9,166 persons (95% C.I. interval 8,973 - 9,877), corresponding to 0.21% (95% CI 0.21%-0.23%) of the Danish population over 15 years of age. The prevalence was highest among persons 40-49 years old (0.39%) and males (0.28%). It was estimated that 40% of the diagnosed patients lived in the capital region, and 33.5% had attended specialised healthcare. It was estimated that 46% of hepatitis C patients had not been diagnosed and the total population with chronic hepatitis C in Denmark was 16,888 (95% C.I. 16,474-18,287), corresponding to 0.38% (95% CI 0.37-0.42) of the population over 15 years of age.

CONCLUSIONS

The estimated prevalence of chronic hepatitis C in Denmark was 0.38%. Less than half of the patients with chronic hepatitis C in Denmark have been identified and among these patients, one in three has attended specialised care.

Molecular epidemiology of a large community-based outbreak of hepatitis B in Bristol, U.K

BACKGROUND

A large outbreak of hepatitis B virus (HBV) infection in the U.K. occurred between 2001 and 2005 in Bristol, U.K.

OBJECTIVES

To identify HBV strains circulating amongst risk groups in the HBV outbreak cohort.

STUDY DESIGN

Cross-sectional study of acute HBV outbreak cases in Bristol.

RESULTS

HBV sequences from sera of 95 of the 237 cases (40%) were characterised. The majority of cases (77%) were found to carry an HBV variant belonging to genotype D, designated HBV(BV). Eighty-eight percent (36/41) of sequences from injection drug users were HBV(BV) as were 70% (19/27) from those with heterosexual intercourse as the primary identified risk factor. Of 15 sequences characterised from cases of pre-outbreak acute or chronic hepatitis B residing in Bristol, 40% also carried HBV(BV); the earliest was from a case identified in 1994.

CONCLUSION

The findings from this study link the spread of HBV(BV) from injecting drug users to the general population through heterosexual intercourse during the outbreak. The molecular sequencing of specimens from this outbreak reports the emergence of HBV(BV), a HBV strain circulating in Bristol and South West England, as the cause of one of the largest outbreaks of acute hepatitis B in the U.K.

Shooting up: the interface of microbial infections and drug abuse

Illicit drug control has been on the global agenda for more than a century. Infections have long been recognized as one of the most serious complications of drug abuse. Drug users are susceptible to pulmonary, endovascular, skin and soft tissue, bone and joint, and sexually transmitted infections caused by a wide range of bacterial, viral, fungal and protozoal pathogens. In addition, injection drug users are at increased risk for parenterally acquired infections such as human immunodeficiency virus, hepatitis B virus, hepatitis C virus, tetanus and malaria. Factors related to drug use, such as unsterile injection practices, contaminated drug paraphernalia and drug adulterants, increase the exposure to microbial pathogens. Illicit drugs also affect several components of the complex immune system and thus modulate host immunity. In addition, lifestyle practices such as multiple sexual partners, overcrowded housing arrangements and malnutrition serve as co-factors in increasing the risk of infection. In this review we present an overview of the unique aspects of microbial pathogenesis, immune modulation and common infections associated with drug use. We have restricted the definition of drug abuse to the use of illegal drugs (such as opiates, marijuana, cocaine, heroin and amphetamines), not including alcohol and nicotine.

Decline in hepatitis B infection observed after 11 years of regional vaccination among Danish drug users

The aims of this study were to determine the current prevalence of viral hepatitis and HIV among drug users, and to compare this prevalence with previous findings in the same geographical region. Cross-sectional surveys of drug users attending treatment centers on the island of Funen with approximately 500,000 inhabitants were administered in 1996 and 2007. The 2007 prevalence estimates were: anti-HBc 50.2%, HBsAg 0.9%, anti-HCV 66.8%, HCV-RNA 40%, and anti-HIV 1.1%. The corresponding 1996 prevalence values were: anti-HBc 70% (P < 0.0001), HBsAg 9.8% (P < 0.0001), anti-HCV 82.8% (P < 0.0001), HCV-RNA 56.3% (P = 0.002), and anti-HIV 1% (P = 1). The 2007 prevalence of viral hepatitis decreased due to the increasing proportion of non-injectors. Among injectors, the prevalence remained unchanged except for a significant decrease in HBsAg. The 2007 prevalence of ongoing HBV infection among infected (HBsAg/anti-HBc proportion) was the lowest that to our knowledge has been reported among drug-users. Vaccination coverage among susceptible persons tested in 2007 was 24%, compared to 0.7% in 1996. Therefore, despite an unchanged prevalence of anti-HBc among injecting drug users, a highly significant drop in HBsAg prevalence was seen during the last decade. This observation may be linked causally to an increase in hepatitis B vaccination of the susceptible population. Our findings suggest that even incomplete vaccination, without persistent protective anti-HBs levels, may induce an immune memory sufficient to prevent chronic infection upon transmission.

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.

Molecular epidemiology of acute hepatitis B in the Netherlands in 2004: nationwide survey

To gain insight into hepatitis B virus (HBV) transmission in the Netherlands, epidemiological data and sera were collected from reported cases of acute HBV infections in the Netherlands in 2004. Cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648 bp) was amplified, sequenced, and subjected to phylogenetic analysis. Of the 291 acute HBV cases reported in 2004, 158 (54%) were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). Of HBV infected men having sex with men, 86% were infected with genotype A, accounting for 43% of all patients infected with this genotype. There were only three reported cases of injecting drug use of which one was available for sequencing (genotype A). Unlike the genotype A cluster, sequences within the genotype B-E clusters were heterogenic. Within genotype F, several isolates had identical sequences, but patients could not be epidemiologically linked. Sexual transmission, particularly by men having sex with men was the most important transmission route for HBV. Injecting drug use plays a minor role. Genotype A is predominant in the Netherlands, especially among men having sex with men. In addition to imported strains, there seems to be a pool of related but non-identical strains circulating among chronic carriers in the migrant population, from which occasionally new patients are infected, primarily by heterosexual transmission.

Should hepatitis B vaccination be introduced into childhood immunisation programmes in northern Europe?

Infection with hepatitis B causes between 500,000 and 1.2 million deaths per year worldwide, and is the leading cause of liver cancer. Over 12 years ago, WHO recommended that universal childhood hepatitis B vaccination be implemented globally. Despite this, Denmark, Finland, Iceland, Ireland, the Netherlands, Norway, Sweden, and the UK have yet to implement such a policy and instead currently adopt an "at-risk" strategy. Although all eight countries are classed as having low endemicity, factors such as increased travel and integration of immigrant communities are increasing the number of at-risk individuals in these countries. Considering the difficulty in identifying all at-risk individuals, and the lack of effectiveness of at-risk vaccination on reducing the overall incidence of hepatitis B, we recommend that these countries reassess their hepatitis B prevention strategies. Universal vaccination against hepatitis B is the only way to eliminate the major public-health impact of this disease.

Acute hepatitis B in the era of immunisation: pitfalls in the identification of high risk patients

BACKGROUND

Since the adoption of a universal hepatitis B immunisation strategy, the reported incidence of acute hepatitis B has declined dramatically worldwide including in Israel. However, new cases of acute hepatitis B still occur. The aim of this study was to describe the incidence of acute hepatitis B in a referral area, routes of transmission, and outcome.

METHODS

The charts of all new hepatitis B patients, who visited the clinic in the years 2002 and 2003 (January 2002 to December 2003), were reviewed. The main criteria for a diagnosis of acute hepatitis B were transient increase of alanine transaminase activity, and hepatitis B surface antigen seroconversion.

RESULTS

Twenty nine men and seven women were diagnosed with acute hepatitis B infection during the study period. Two patients were previously vaccinated with hepatitis B vaccine. One case of hepatitis D coinfection was reported. The incidence of acute hepatitis B in the referral area was estimated as 2.25 per 100,000 adult population. Mean age was 36 years (17-75). Twenty one patients (18 men and 3 women) acquired the virus through unprotected sexual contact, and seven patients through iatrogenic exposure. Thirty three patients underwent spontaneous seroconversion while three patients became chronic carriers.

CONCLUSIONS

Despite a universal immunisation policy, frequent cases of acute hepatitis B in Israel are still seen. High risk heterosexual activity and iatrogenic exposure seem to be the commonest routes of transmission. Further recommendations regarding vaccination policy are discussed.

Prevention of viral hepatitis in the Nordic countries and Germany

The Viral Hepatitis Prevention Board (VHPB) convened a meeting of international experts from the public and private sectors in the Nordic countries and Germany, in order to review the epidemiological situation, the surveillance systems for infectious diseases, the immunization programmes and policy, and the monitoring of adverse events after hepatitis vaccination in those countries, to evaluate prevention and control measures, and to identify the issues that arose and the lessons learnt. Considerable progress has been made in the past decades in the prevention and control of viral hepatitis in the respective countries. Vaccination programmes have been set up, blood products' safety has significantly been improved, and outbreak investigations remain the basis for the implementation of control measures. However, additional work remains to be done. Awareness of viral hepatitis among the public and professionals should further be raised, and more political support is needed regarding the value of prevention efforts and vaccination programmes.

Cloning of HBsAg-encoded genes in different vectors and their expression in eukaryotic cells

AIM: To compare the efficiency of different plasmids as DNA vectors by cloning three HBsAg-encoded genes into two eukaryotic expression vectors, pRc/CMV and pSG5UTPL/Flag, and to express HBsAg S, MS, and LS proteins in SP2/0 cells, and to establish monoclone SP2/0 cell strains that are capable of expressing S or S2S proteins stably.

METHODS: Segments of S, preS2-S, preS1-preS2-S genes of Hepatitis B virus were amplified by routine PCR and preS1-S fragment was amplified by Over-Lap Extension PCR. The amplified segments were cleaved with restricted endonuclease Hind III/Not I followed by ligation with pRc/CMV, or BamH I/EcoR I followed by ligation with pSG5UTPL/Flag. After the plasmid vectors were cleaved with the correspond enzymes, the amplified segments were inserted into pRc/CMV or pSG5UTPL/Flag plasmid vectors with T4 DNA ligase. KOZAK sequence was added before the initial ATG code of each fragment using specific primer. The inserted segments in the recombinant plasmids were sequenced after subcloning. BALB/c mice myeloma cells (SP2/0 cell line) were transfected with the recombinant plasmids. The expressions of the different recombinants were Compared by Western-blot, using a monoclonal anti-HBs antibody as the primary antibody and peroxidase-labeled multi-linker as the secondary. Stable SP2/0-pRc/CMV-S or SP2/0-pRc/CMV-MS clones were established through clone screening with G418.

RESULTS: Fragments with anticipated size were harvested after PCR. After recombination and screening, the sequences of the inserted segments in the recombinants were confirmed to be S, preS2S, preS1-preS2S and preS1S encoding genes, determined by sequencing. The results of Western-blot hybridization were positive for the anticipated proteins. Among them, pRc/CMV-S or pRc/CMV-MS demonstrated the highest expressing their respective antigen.

CONCLUSION: Eight recombinant plasmids expressing S, M, L or preS1S proteins are obtained. For hepatitis surface antigen expression in eukaryotic cells, the vector pRc/CMV is superior to pSG5UTPL/Flag, and pRc/CMV-S and pRc/CMV-MS are the most efficient in the pRc/CMV clones. SP2/0 cells stably expressing HBsAg are established, and may be used as target cells for evaluating the CTL activity of a DNA vaccine in vitro.

Low hepatitis B prevalence among pre-school children in Denmark: saliva anti-HBc screening in day care centres

Although Denmark has a low hepatitis B virus (HBV) prevalence, HBV transmission has been reported in Danish day-care centres. The aim of this study was to validate saliva anti-HBc testing as a method for HBV screening, the applicability of saliva sampling to pre-school children, and to determine the HBV prevalence in Danish day-care centres with a high proportion of immigrants. For validation, paired saliva and plasma samples were obtained from blood donors and injecting drug users. Employees and children in day-care centres with a high proportion of immigrant children were offered saliva screening followed by blood test if positive. The specificity and sensitivity of anti-HBc tests on saliva was 100% (102 blood donors and four injecting drug users) and 85.9% (61 of 71 anti-HBc-positive injecting drug users), respectively. In all samples from HBsAg (n = 7) or anti-HBc IgM-positives (n = 9), anti-HBc was detected in saliva. Adequate saliva samples were obtained from 93% (588/634) of children and 100% (166/166) of employees participating in the day-care centre survey. Among children 55% were of non-Scandinavian origin and only one (0.2%, 95% CI [0.0; 1.0]) was HBV positive. Among employees the corresponding values were 22% and 7 (4.2%). The positive predictive value of the saliva test was 25% (1/4) among children and 88% (7/8) among adults. In conclusion, saliva testing is feasible for HBV screening among children in low prevalence populations, but any anti-HBc reactivity should be confirmed by plasma analysis. The HBV prevalence in pre-school children in Denmark is low even among immigrants from endemic areas.