Sexual transmission of hepatitis D virus infection in Taiwan

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.

Epidemiology, presentation, and therapeutic approaches for hepatitis D infections

INTRODUCTION

Chronic Hepatitis D virus (HDV) infection remains an important global public health problem, with a changing epidemiological landscape over the past decade along with widespread implementation of hepatitis B vaccination and human migration. The landscape of HDV treatments has been changing, with therapies that have been under development for the last decade now in late stage clinical trials. The anticipated availability of these new therapies will hopefully replace the current therapies which are minimally effective.

AREAS COVERED

This narrative review discusses the clinical course, screening and diagnosis, transmission risk factors, epidemiology, current and investigational therapies, and liver transplantation in HDV. Literature review was performed using PubMed and ClinicalTrials.gov and includes relevant articles from 1977 to 2022.

EXPERT OPINION

HDV infection is an important global public health issue with a true prevalence that is still unknown. The distribution of HDV infection has changed globally with the availability of HBV vaccination and patterns of human migration. As HDV infection is associated with accelerated disease courses and poor outcomes, the global community needs to agree upon a uniform HDV screening strategy to understand the truth of global prevalence such that new therapies can target appropriate individuals as they become available in the future.

Epidemiology and Risk Factors for Acute Viral Hepatitis in Bangladesh: An Overview

Viral infections by hepatotropic viruses can cause both acute and chronic infections in the liver, resulting in morbidity and mortality in humans. Hepatotropic viruses, including hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV), are the major pathogens that cause acute and chronic infections in humans. Although all of these viruses can cause acute hepatitis in humans, HAV and HEV are the predominant causative agents in Bangladesh, where the occurrence is sporadic throughout the year. In this review, we provide an overview of the epidemiology of hepatotropic viruses that are responsible for acute hepatitis in Bangladesh. Additionally, we focus on the transmission modes of these viruses and the control and prevention of infections.

Hepatitis D virus infection in a large cohort of immigrants in southern Italy: a multicenter, prospective study

Background

Since few data are available in the literature on the prevalence of anti-Delta-positive subjects in immigrant populations, the aim of the present study was to evaluate the demographic and virological characteristics of HDV infection in a large cohort of immigrants living in southern Italy.

Methods

Between January 2012 and February 2020 all immigrants attending one of the 5 first- level centers were enrolled and screened for HBsAg, the HBsAg-positive for anti-Delta and if positive, for HDV-RNA and HDV genotype.

Results

Of the 3521 immigrants observed in the study period, 3417 (97.0%) agreed to be screened; they were mainly males (61%), with a median age of 27 years (IQR 8–74) and came prevalently (58%) from sub-Saharan Africa.

Of the 3417 patients enrolled, 319 (9%) subjects were HBsAg-positive, and of those, 8 (2.5%) were anti-Delta-positive. No difference in the demographic and epidemiological characteristics was observed between the anti-Delta-negative vs -positive. Of the 8 anti-Delta-positive subjects, only one was HDV-RNA-positive (viral load: 7050 IU/mL), genotype 1, with clinical signs of cirrhosis.

Conclusions

the present study showed a prevalence of HDV of 2.5% in a large cohort of asymptomatic immigrants, suggesting the need for screening campaigns for viral infections including delta hepatitis in this population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01938-0.

HDV infection in immigrant populations

AIMS

Little data have been published so far on the epidemiological aspects of hepatitis D virus (HDV) infection in immigrant populations and even poorer is the information on the virological, phylogenetic, and clinical aspects of this infection in these populations. This review article, aimed primarily at physicians caring for immigrants, summarizes the information available on HDV infection and analyzes data on this topic concerning the immigrant populations.

METHODS AND RESULTS

The prevalence of HDV infection in HBsAg-positive immigrants varies according to the country of origin. For example, in immigrants from sub-Saharan Africa, this prevalence is higher in those born in Equatorial Guinea (24.4%) than those from other African countries (10.3%). The epidemiological impact of HDV infection linked to migratory flows is a function of the different endemicity between countries of origin and countries in which a new existence has been established. This impact is high when immigrants from areas endemic to HDV infection (eg, Equatorial Guinea) settle in areas of low endemicity (eg, Germany or England, with a prevalence of around 4%), while the impact is lesser or nonexistent if the migratory flows are directed toward countries with intermediate endemicity (eg, Italy and Greece, with a prevalence of around 10%).

CONCLUSION

This impact of immigration on HDV epidemiology can be strong when HDV endemicity is high in the country of origin and low in the host country and slight when immigrants move to high or medium endemic countries.

Increasing incidence of recent hepatitis D virus infection in HIV-infected patients in an area hyperendemic for hepatitis B virus infection

BACKGROUND

Superinfection with hepatitis D virus (HDV) may increase the risk for hepatitis flares and chronic hepatic complications in patients with chronic hepatitis B virus (HBV) infection. This retrospective observational study aimed to examine the incidence of and factors associated with recent HDV superinfection among individuals coinfected with human immunodeficiency virus (HIV) and HBV.

METHOD

Anti-HDV immunoglobulin G (IgG) was sequentially determined in 375 HIV/HBV-coinfected patients to estimate the HDV incidence between 1992 and 2012. Plasma HDV and HBV loads and HBV surface antigen (HBsAg) levels were determined for the HDV seroconverters. A nested case-control study was conducted to identify the associated factors with HDV seroconversion. Phylogenetic analysis was performed using HDV sequences amplified from HDV seroconverters and HDV-seropositive patients at baseline.

RESULTS

During 1762.4 person-years of follow-up [PYFU], 16 patients seroconverted for HDV, with an overall incidence rate of 9.07 per 1000 PYFU, which increased from 0 in 1992-2001, to 3.91 in 2002-2006, to 13.26 per 1000 PYFU in 2007-2012 (P < .05). Recent HDV infection was associated with elevated aminotransferase and bilirubin levels and elevated rapid plasma reagin titers. Of the 12 patients with HDV viremia, 2 were infected with genotype 2 and 10 with genotype 4. HBsAg levels remained elevated despite a significant decline of plasma HBV DNA load with combination antiretroviral therapy that contained lamivudine and/or tenofovir.

CONCLUSIONS

Our findings show that the incidence of recent HDV infection in HIV/HBV-coinfected patients increased significantly from 1992-2001 to 2007-2011, and was associated with hepatitis flares and syphilis.

Molecular epidemiology of hepatitis D virus infection among injecting drug users with and without human immunodeficiency virus infection in Taiwan

An outbreak of human immunodeficiency virus (HIV) infection occurred among injecting drug users (IDU) in Taiwan between 2003 and 2006, when an extremely high prevalence of hepatitis C virus (HCV) infection was also detected. To determine whether clusters of hepatitis D virus (HDV) infection occurred in this outbreak, 4 groups of subjects were studied: group 1, HIV-infected IDU (n = 904); group 2, HIV-infected non-IDU (n = 880); group 3, HIV-uninfected IDU (n = 211); and group 4, HIV-uninfected non-IDU (n = 1,928). The seroprevalence of hepatitis B virus (HBV) was 19.8%, 18.4%, 17.1%, and 6.7%, and HDV seroprevalence among HBV carriers was 75.4%, 9.3%, 66.7%, and 2.3%, for groups 1, 2, 3, and 4, respectively. Ninety-nine of 151 (65.6%) HDV-seropositive IDU had HDV viremia: 5 were infected with HDV genotype I, 41 with genotype II, 51 with genotype IV, and 2 with genotypes II and IV. In the phylogenetic analysis, only one cluster of 4 strains within the HDV genotype II was identified. Among patients with HCV viremia, a unique cluster within genotype 1a was observed; yet, patients within this cluster did not overlap with those observed in the HDV phylogenetic analysis. In summary, although IDU had a significantly higher HDV seroprevalence, molecular epidemiologic investigations did not support that HDV was introduced at the same time as HCV among IDU.

Natural Course and Treatment of Hepatitis D Virus Infection

Hepatitis D virus (HDV) is a subviral satellite with hepatitis B virus (HBV) as its natural helper virus. After entry into hepatocytes, it utilizes host cellular enzymes to replicate by a double-rolling-circle mechanism. HDV is most often transmitted by contact with contaminated blood and body fluid, similar to HBV infection. Approximately 5% of the global HBV carriers are coinfected with HDV, leading to a total of 10-15 million HDV carriers worldwide. HDV infection can occur concurrently with HBV infection (coinfection) or in a patient with established HBV infection (superinfection). The pathogenesis of HDV remains controversial. A decline in the prevalence of both acute and chronic hepatitis D (CHD) has been observed worldwide. At present, therapy for chronic HDV infection is by the use of interferon-alpha. Compared to chronic hepatitis B or C, CHD treatment requires a higher dosage and a longer duration of treatment, and post-treatment relapses are common. In order to prevent the progression of CHD and its related morbidity and mortality, more effective treatments are needed.

Molecular epidemiological and clinical aspects of hepatitis D virus in a unique triple hepatitis viruses (B, C, D) endemic community in Taiwan

The molecular epidemiological and clinical aspects of hepatitis D virus (HDV) in a unique HBV, HCV, and HDV triple virus endemic community in southern Taiwan were investigated. A total of 2,909 residents aged 45 or older were screened for hepatitis B surface antigen (HBsAg), anti-HCV antibody, and anti-HDV antibody (specifically for HBsAg-positive carriers). Factors that might be associated with HDV infection, viral nucleic acid detection, and genotyping of HBV, HCV, and HDV were investigated. The prevalence of HBsAg and anti-HCV were 12.6% (366/2,909) and 41.6% (1,227/2,909), respectively. For HBsAg carriers, 15.3% (56/366) were positive for anti-HDV assay. Living in a higher endemic district of HCV infection (odds ratio [OR] = 3.2; 95% confidence interval [CI] = 1.7-6.3), male gender (OR = 1.9; 95% CI = 1.1-3.6) and co-infection with HCV (OR = 1.8; 95% CI = 1.0-3.3) were significantly independent factors associated with HDV infection. The detection rate of HDV RNA among anti-HDV-positive patients was only 12.7% (7/55). The mean HBV titer of triple infection group was significantly lower than in the HBV/HDV co-infection group (2.23 vs 3.05 in log(10), copies/ml, P = 0.046). HCV RNA detection among the triple infection group showed 47.4% (9/19) viremia rate and viral loads of 579,121 IU/ml in median (16,803-1,551,190 IU/ml). The prevalent genotype of HBV was type B (23/25); HCV was 1b (7/9) and HDV was IIa/IIb (4/4). Only the presence of HCV RNA predicted the presence of elevated ALT significantly (OR = 25.0; 95% CI = 3.39-184.6). In conclusion, the geographical aggregation of HDV infection paralleled that of HCV infection in this community. HCV suppressed the replication of HBV among triple vital infection patients. HBV and HDV lapsed into a remission or nonreplicative phase in most cases, and HCV acted as a dominant factor in triple viral-infected individuals. Only the presence of HCV RNA was associated with elevated ALT values, but not HBV or HDV.

Molecular cloning and expression of the hepatitis delta virus genotype IIb genome

Analysis of hepatitis delta virus (HDV) genome sequences has revealed multiple genotypes with different geographical distributions and associated disease patterns. To date, replication-competent cDNA clones of HDV genotypes I, II, and III have been reported. HDV genotypes I, II, and IIb have been found in Taiwan. Although full-length sequences of genotype IIb have been published, its replication competence in cultured cells has yet to be reported. In order to examine this, we obtained a full-length cDNA clone, Taiwan-IIb-1, from a Taiwanese HDV genotype IIb isolate. Comparison of the complete nucleic acid sequence of Taiwan-IIb-1 with previously published genotype IIb isolates indicated that Taiwan-IIb-1 shares 98% identity with another Taiwanese isolate and 92% identity with a Japanese isolate. Transfection of Taiwan-IIb-1 into COS7 cells resulted in accumulation of the HDV genome and appearance of delta antigens, showing that cloned HDV genotype IIb can replicate in cultured cells.

Changing seroepidemiology of hepatitis B, C, and D virus infections in high-risk populations

Needle-sharing and sexual contact are important transmission routes of hepatitis B, C, and D virus (HBV, HCV, HDV) infection. This study aimed to investigate the current status of these viral infections among high-risk populations including prostitutes and intravenous (i.v.) drug users, compared with the prevalence rate reported previously to examine the changing seroepidemiology. Of the 916 female prostitutes, 79 (9%) were positive for antibody to HCV (anti-HCV), 111 (12%) were positive for HBV surface antigen (HBsAg), and 5 (5%) had antibody to HDV (anti-HDV). The prevalence rate was significantly lower compared to that in 1989-1991 (12%, P = 0.037) for HCV infection, and to that in 1988 (59%) and 1996 (40%) (P < 0.0001) for HDV infection. Of the 494 i.v. drug users, 87 (18%) patients were HBsAg carriers and 12 (14%) were anti-HDV-positive. The prevalence rate of HDV infection was significantly lower than that reported in 1985 (79%, P < 0.0001). Among the 443 tested i.v. drug users, 182 (41%) were anti-HCV-positive, significantly lower than that in 1985 (53%, P = 0.026). Of the 263 male prostitutes, 11 (4%) were anti-HCV-positive, 45 (17%) were HBsAg-positive, and 7 (16%) were anti-HDV-positive. Of the 129 illegal immigrant prostitutes, 7 (5%) were anti-HCV-positive, 15 (12%) were HBsAg-positive and none were positive for anti-HDV. In conclusion, the findings indicate a declining prevalence of HCV and HDV infections among drug users and prostitutes over the past 16 years. Male prostitutes and immigrant prostitutes are new "high-risk" populations and may become a reservoir for disease transmission.

Seroprevalence of GB virus C/hepatitis G virus-RNA and anti-envelope antibody in high-risk populations in Taiwan

BACKGROUND

GB Virus C (GBV-C)/hepatitis G virus (HGV) was identified in 1995-1996 as a transfusion-transmissible virus. The diagnosis of GBV-C/HGV infection is based on the detection of GBV-C/HGV-RNA by using polymerase chain reaction. Recently, an enzyme immunoassay detecting the antibodies to the viral protein, E2 envelope protein (anti-envelope) of GBV-C/HGV, has been developed.

METHODS

Serum GBV-C/HGV-RNA and anti-envelope antibody were determined in 76 cases of intravenous drug users (IVDU), 76 patients with regular hemodialysis and in 80 prostitutes to evaluate the GBV-C/HGV infection rate among high-risk populations in Taiwan. Seventy-six healthy blood donors were randomly selected and were used as a control group.

RESULTS

The prevalence of GBV-C/HGV-RNA in high-risk populations was 33% for IVDU, 16% for patients with hemodialysis and 13% for prostitutes, which was significantly higher than the 3% obtained in the control group (P < 0.05 for all groups). The prevalence of anti-envelope antibody was 13% for IVDU, 21% for patients with hemodialysis and 23% for prostitutes, which was not significantly different from the control group (11%). Among the 99 subjects who had positive GBV-C/HGV markers, 97 were tested for exclusive positivity for either GBV-C/HGV-RNA or anti-envelope antibody.

CONCLUSIONS

The presence of serum anti-envelope antibody usually indicates the clearance of serum GBV-C/HGV-RNA in patients infected with GBV-C/HGV. GBVirus-C/HGV infection in high-risk populations, determined by the presence of serum GBV-C/HGV-RNA, may underestimate the true level of past and present infection.

Prevalence and risk factor analysis of TTV infection in prostitutes

TTV, a DNA virus, has been isolated from patients with non-A to non-E post-transfusion hepatitis. In the past it was assumed that TTV was transmitted parenterally. It is unclear whether sexual contact leads to transmission of this virus. In this study, two sets of TTV-specific polymerase chain reaction primers were used to detect serum TTV DNA in 140 prostitutes and 136 controls. The prevalence of TTV DNA in prostitutes was significantly higher than in the control group (46/140 [32.9%] vs. 29/136 [21.3%]; P = 0.043). There was no significant difference in the prevalence of positive antibody to hepatitis A virus (anti-HAV) in either group (87.8% for prostitutes, 85.3% for controls). No particular risk factor was significantly associated with positive TTV DNA in prostitutes. In summary, TTV is highly prevalent in prostitutes. Transmission of TTV via sexual contact is not as efficient as transmission of hepatitis C and D viruses and GB virus-C hepatitis G virus. The high prevalence of TTV in controls indicates that there are diverse routes of transmission of this virus.

Detection and viral nucleotide sequence analysis of transfusion-transmitted virus infection in acute fulminant and non-fulminant hepatitis

The impact of transfusion-transmitted virus (TTV) infection on acute fulminant and non-fulminant hepatitis is unclear. In this study, serum samples from 164 patients with acute hepatitis of various aetiologies, from 34 asymptomatic hepatitis B virus carriers and from 202 healthy adults were tested for TTV DNA by the semiconserved nested polymerase chain reaction. TTV viraemia was prevalent in patients with acute hepatitis C, in patients with acute hepatitis D virus superinfection and in patients with non-A-E hepatitis (27-30%) but the incidence was not significantly different from that of healthy controls (31 of 202, 15.3%). There were no significant differences in gender, age, presence of hepatitis G virus, the occurrence of fulminant hepatitis, or in serum albumin, bilirubin or alanine aminotransferase levels (9/30 vs 35/134) between patients with or without TTV viraemia. Seven of the nine TTV-positive patients with fulminant hepatitis were co-infected with hepatitis C, D or E. TTV clones from 18 subjects, with or without fulminant hepatitis, were sequenced and analysed phylogenetically. Eleven (61. 1%) belonged to TTV group 1, six (33.3%) to TTV group 2 and one to TTV group 3. No particular strain of TTV was associated with fulminant hepatitis. In summary, in Taiwan, TTV is prevalent in the general population as well as in patients with liver diseases. TTV plays an insignificant role in acute fulminant and non-fulminant hepatitis. Its influence on outcome requires a longitudinal study.

Prevalence, implication, and viral nucleotide sequence analysis of GB virus-C/hepatitis G virus infection in acute fulminant and nonfulminant hepatitis

The clinical impact of GB virus-C (GBV-C)/hepatitis G virus (HGV) infection on various causes of acute hepatitis and fulminant hepatitis is controversial. In this study, serum samples from 164 patients with acute hepatitis of various causes, 34 asymptomatic hepatitis B virus (HBV) carriers, and 34 healthy adults were tested for GBV-C/HGV RNA by reverse transcription-nested polymerase chain reaction using primers based on the 5'-untranslated region. Nucleotide sequences of GBV-C/HGV RNA from various groups were compared. The prevalence of GBV-C/HGV RNA was significantly higher in patients with acute hepatitis D virus (HDV) superinfection than in HBV carriers or healthy controls (10/37 vs. 2/34, P < 0.02; 10/37 vs. 1/34, P < 0.005). GBV-C/HGV RNA was detected in 11.1% of acute hepatitis A patients, 9.5% of acute hepatitis B patients, 15.8% of acute hepatitis C patients, 12.5% of acute hepatitis E patients, 11.8% of chronic hepatitis B patients with acute exacerbation, and 11.1% in patients with non-A to -E hepatitis; each was not significantly higher than that in HBV carriers or healthy adults. There were no significant differences in gender, age, serum albumin, bilirubin, and alanine aminotransferase levels nor in the occurrence of fulminant hepatitis (6/28 vs. 36/136) between patients with or without GBV-C/HGV RNA. All six patients with fulminant hepatitis who had GBV-C/HGV RNA were complicated by infection with hepatitis B, C, or D. The GBV-C/HGV clones from 21 patients with or without fulminant hepatitis belonged to group 3. No particular strain of GBV-C/HGV was associated with fulminant hepatitis.

Decreasing hepatitis D virus infection in Taiwan: an analysis of contributory factors

Superinfection of hepatitis D virus (HDV) among hepatitis B virus (HBV) carriers is mainly through heterosexual contact in Taiwan. This study investigated the change of HDV endemicity and its associated contributory factors. Seventy-seven patients with acute HDV superinfection among 527 consecutive exacerbating hepatitis B surface antigen (HBsAg) carriers were identified over the past 12 years. The prevalence decreased significantly by each 3-year period from June 1983 to May 1995 (23.7, 15.5, 13.1 and 4.2%, respectively, P < 0.001). This trend was more significant in the hepatitis B e antigen (HBeAg)-negative group (P < 0.001) than in the HBeAg-positive group (P = 0.073). Subjects with a history of paid sex and prostitutes were also recruited for analysis both in 1989 and 1996. Although not statistically significant, there was a trend showing a decrease in the prevalence of serum antibody against HDV (anti-HDV) in each risk group: it was lower in 1996 among HBsAg-positive brothel-goers (10.3 vs 6.9%), licensed prostitutes (54.5 vs 50%) and unlicensed prostitutes (36.1 vs 30.8%). Accumulation of anti-HDV-positive subjects in risk groups may mask the actual decrease of new HDV-infected cases. The prevalence of the HBsAg carrier rate among all prostitutes has significantly decreased (18.3 vs 12.2%, P = 0.015). The efficacy of each preventive strategy was examined and mapped with the trend. It was concluded that active preventive measures directed against promiscuity and sexually transmitted disease and the promotion of disposable needles may have contributed to the decrease in HDV endemicity.

Comparison of clinico-pathological features in hepatitis B virus-associated hepatocellular carcinoma with or without hepatitis D virus superinfection

BACKGROUND/AIMS

Hepatitis D virus superinfection in hepatitis B virus carriers produces additional damage in an already injured liver. Earlier reports noted that the development of hepatocellular carcinoma may be accelerated in hepatitis D virus-superinfected patients. This study aimed to investigate the impact of hepatitis D virus on the clinical course of hepatitis B virus-associated hepatocellular carcinoma.

METHODS

A total of 42 consecutive hepatocellular carcinoma cases seropositive for antibody against hepatitis D virus antigen (anti-HDV) were found from 1986 to 1994; the clinical manifestations, treatment and outcomes were compared with 255 consecutive hepatocellular carcinoma cases seropositive for hepatitis B virus surface antigen but seronegative for anti-HDV.

RESULTS

The mean age was 60 years in both groups of patients. Other features, including sex, duration of follow-up, presence of cirrhosis or ascites, serum biochemistry, status of HBV-e antigen, and gross and microscopic tumor appearance, were not significantly different between the two groups. Though more patients in the anti-HDV-positive group underwent active treatment (operation or transcatheter arterial chemoembolization) than those in the anti-HDV-negative group (54.8% in 42 versus 34.9% in 255 cases, p = 0.02), the cumulative 4-year survival rates (9.5% versus 9.8%) were similar. For the anti-HDV-positive hepatocellular carcinoma patients, tumor size < 5 cm and active treatment were favorable prognostic predictors associated with survival > 18 months.

CONCLUSION

Hepatitis D virus superinfection does not accelerate the development of hepatocellular carcinoma. The clinical manifestations were similar, and the outcome in anti-HDV-positive patients was not worse than in the general HBV-associated hepatocellular carcinoma patients, as long as they were diagnosed at an early stage and actively treated.

Evidence of transmission of hepatitis D virus to spouses from sequence analysis of the viral genome

To study sexual transmission of hepatitis D virus (HDV), 52 spouses of 56 index patients were observed and HDV genomes from antibody to HDV (anti-HDV)-positive couples were sequenced. Of the spouses, 11 (21%) were serum HBsAg positive, 3 (27%) of whom were also anti-HDV positive. The HDV sequences between spouses were found to be nearly identical (98% to 98.8%) in the region analyzed (nt 911 to nt 1260). Only one couple showed an identity > 90% with the genotype I HDV strains. The HDV sequences of the remaining two couples showed > 95% identity with each other and > 91% homology with genotype II, but they shared only a 73.1% to 73.7% homology with those of the first couple. The regions corresponding to the autocatalytic cleavage sites, the junction between the middle and the carboxyl terminal one-third domains, and the middle domain of the open reading frame for delta antigen on the antigenomic HDV RNA were more conserved with < 19% divergence among the three couples. Interestingly, there was a 56% divergence in the region corresponding to the carboxyl end of the open reading frame for the large delta antigen on the antigenomic HDV RNA. In summary, this study provides a direct nucleotide evidence of a common source of HDV infection in each couple. Despite divergence in the viral nucleotide sequence, both genotypes I and II were found in Taiwan and were transmitted from patients with a history of prostitute contact to spouses through sexual contact.

Injection with nondisposable needles as an important route for transmission of acute community-acquired hepatitis C virus infection in Taiwan

A prospective case-controlled study was conducted in order to determine the transmission route of community-acquired hepatitis C virus (HCV) infection in Taiwan. Thirty-eight consecutive patients (25 men and 13 women) with acute community-acquired HCV infection and 76 age (within 3 years)- and sex-matched healthy control subjects without HCV infection were enrolled. Serum anti-HCV was tested by second generation immunoassay. The sera of 26 family members from 12 families of index patients were also tested for anti-HCV. A questionnaire covering the history of blood transfusion, surgery, intravenous drug abuse, prostitute contact, dental procedures, injection, acupuncture, tattooing, and ear-piercing was conducted among patients and control subjects. Univariate analysis revealed injection with nondisposable needles was an independent risk factor (P = 0.02, odds ratio = 4.17, 95% confidence interval = 1.24-14.47) associated with HCV infection. Other risk factors were not significant. Only 2 (7.7%) family members of index patients had an anti-HCV. In conclusion, more vigorous effort to prohibit the use of nondisposable needles should be promoted to interrupt the spread of community-acquired HCV infection in Taiwan. Of note, a significant number of patients (34.2%) contracted HCV infection without identifiable risk factors. Unidentified routes need to be investigated.

Natural history of hepatitis D viral superinfection: significance of viremia detected by polymerase chain reaction

BACKGROUND/AIMS

Polymerase chain reaction (PCR) is very sensitive. The aim of the study was to reevaluate viral replication in hepatitis D virus (HDV) superinfection by PCR.

METHODS

HDV and hepatitis B virus (HBV) were detected by PCR in 185 patients.

RESULTS

The acute hepatitis group had the highest detection rate of HDV RNA compared with chronic hepatitis, cirrhosis, hepatocellular carcinoma, and remission groups (63 of 64 vs. 35 of 47, 17 of 23, 19 of 30, and 7 of 21) and the highest alanine aminotransferase (ALT) levels (mean, 1741 U/L vs. 266 to 27 U/L; P < 0.05). The detection rate of HBV DNA was the lowest in the acute group (41%) compared with 66%, 70%, 80%, and 57% in the remaining groups (P < 0.02). At the chronic stage, 13%-25% of cases had HDV RNA, and 30%-48% of cases had HBV DNA detected by PCR but not by traditional method. HDV RNA was associated with ALT levels in horizontal and longitudinal analyses.

CONCLUSIONS

HDV superinfection may be divided into the following three phases: acute phase, active HDV replication and suppression of HBV with high ALT levels; chronic phase, decreasing HDV and reactivating HBV with moderate ALT levels; and late phase, development of cirrhosis and hepatocellular carcinoma caused by replication of either virus or remission resulting from marked reduction of both viruses.

The role of hepatitis C virus in fulminant viral hepatitis in an area with endemic hepatitis A and B

BACKGROUND/AIMS

The role of hepatitis C virus in fulminant hepatitis remains controversial and needs further investigation. The aim of this study was to examine the role of hepatitis C virus in fulminant hepatitis in an area with endemic hepatitis A and B.

METHODS

Serological markers of hepatitis C virus were studied in 62 adults from Taiwan with fulminant viral hepatitis.

RESULTS

Of 62 patients, 5 (8.1%) were infected with acute type B hepatitis, 11 (17.7%) were infected with acute non-A, non-B hepatitis, and the remaining 46 (74.2%) were hepatitis B surface antigen (HBsAg) positive but immunoglobulin M (IgM) antibody to hepatitis B core antigen negative. Of the latter, 11 (23.9%) were IgM antibody to hepatitis D virus positive, 16 (34.8%) had high-titered serum hepatitis B virus DNA (> 1000 pg/mL) and were suspected to have hepatitis B virus reactivation, and the other 19 (41.3%) had no identified causes. Serum hepatitis C virus RNA was found in 5 (45.5%) of 11 patients with fulminant non-A, non-B hepatitis, 3 (27.3%) of 11 HBsAg carriers with delta superinfection, and 6 (31.6%) of 19 HBsAg carriers with fulminant hepatitis of undetermined cause.

CONCLUSIONS

Nearly half of fulminant non-A, non-B hepatitis and about 20% of HBsAg carriers with superimposed fulminant hepatitis in Taiwan could be attributed to hepatitis C virus infection.

Multiple viral infection as the most common cause of fulminant and subfulminant viral hepatitis in an area endemic for hepatitis B: application and limitations of the polymerase chain reaction

We tested serum samples from 25 fulminant hepatitis and 7 subfulminant hepatitis patients for hepatitis A, B, C, D and E viral markers and nucleic acids by means of polymerase chain reaction to determine the role of each virus on such catastrophic events in an area endemic for hepatitis B. Of these 32 patients, 14 (44%) were hepatitis B virus carriers with hepatitis D virus superinfection (1 with hepatitis C virus infection), 3 others had coexisting hepatitis B virus and hepatitis C virus infections, 6 had reactivation of underlying chronic hepatitis B, 4 had acute hepatitis B, 2 had acute hepatitis C and 1 had acute hepatitis E. Pathogenesis in the remaining two cases was unclear. Serum hepatitis B virus DNA was detectable in most carriers without superinfection and in one third of those with superinfection detected on polymerase chain reaction (6 of 7 vs. 6 of 16, p < 0.05). Of the polymerase chain reaction-positive samples, only 17% yielded positive results on spot hybridization. Hepatitis B virus DNA was the only marker to indicate coexisting hepatitis B virus infection in one patient positive for hepatitis C virus antibody. Only three of the six hepatitis C virus-infected cases were positive for hepatitis C virus antibody; diagnoses in the remaining three were established by means of detection of hepatitis C virus RNA. Of the hepatitis D virus-infected patients, infection in only half was diagnosed by means of total hepatitis D virus antibody assay. Twelve (86%) were positive for anti-hepatitis D virus IgM and nine (64%) had detectable hepatitis D virus RNA on reverse transcription-polymerase chain reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors associated with viremia and elevated transaminase levels in asymptomatic hepatitis D virus-infected risk groups

To detect hepatitis D virus (HDV) RNA in asymptomatic HDV-infected risk groups, Northern blot hybridization was carried out using a strand-specific riboprobe. Univariate and multivariate analyses were carried out to evaluate factors associated with HDV viremia and elevated transaminase levels in these subjects. Two (15%) of 13 antibody to HDV (anti-HDV) -positive intravenous drug addicts, 15 (33%) of 45 anti-HDV positive prostitutes, and 6 (40%) of 15 anti-HDV positive brothel goers had detectable serum HDV RNA. Older age (> 31 years old) was negatively associated with HDV RNA (P < .04), while hepatitis B e antigen (HBeAg) was positively associated with it (P < .002) in univariate analysis. Only HBeAg was still significant in multivariate analysis (P < .05). Of the 76 asymptomatic anti-HDV positive case, 28 (37%) had mildly elevated serum ALT levels and only 5 (7%) had ALT levels more than twice normal (> 80 U/L). HBeAg (P < .05) and HDV RNA (P < .02) were two factors associated with ALT elevation in univariate analysis, and HDV RNA was the only significant factor in multivariate analysis (P < .005). In summary, active replication of HBV seemed to be of help for the assembly of HDV and viremia. However, active replication of HDV was associated mostly with mildly elevated ALT levels in these subjects. These cases may represent a particular group in the disease spectrum of HDV infection.

Risk of liver cirrhosis and hepatocellular carcinoma in subjects with hepatitis B and delta virus infection: a study from Kure, Japan

To investigate the effect of hepatitis delta virus (HDV) superinfection on the long-term outcome of Japanese subjects with chronic hepatitis B virus (HBV) infection, we examined the presence of antibodies to hepatitis delta antigen (anti-HD) in serial serum samples collected from 1127 subjects with chronic HBV infection. The subjects were followed for at least 36 months (mean: 121.3 months) between 1973 and 1991. Among 69 cases where anti-HD was detected, eight (12%) developed liver cirrhosis (LC) and six (9%) developed hepatocellular carcinoma (HCC). However, among 1058 cases without anti-HD, there were 43 patients (4%) who developed LC and 29 (3%) who developed HCC. The prevalence of LC and HCC was significantly higher among the cases with anti-HD than those without anti-HD. The proportion of LC and HCC per 1000 person years was 10.46 and 7.84, respectively among cases with anti-HD, and 4.05 and 2.73 among those without anti-HD, respectively. The overall relative risk of LC and HCC was 2.58 and 2.87, respectively; 95% confidence interval (CI): LC, 1.14-5.13; HCC, 1.03-6.23. These results indicate that in the Kure district in Japan, where HDV infection of persons infected with HBV is about 6%, such superinfection increases the risk of LC and HCC.

Hepatitis D virus infection among prostitutes in Taiwan

Two hundred and sixty-three adult licensed, 233 adult and 157 teenage unlicensed prostitutes from Taiwan were studied for prevalence and risk factors of hepatitis D virus (HDV) infection. The hepatitis B carrier rate among the three groups was 21, 15 and 20%, respectively, not significantly different from that of the general population in this area. However, the prevalence of HDV infection among carrier prostitutes was 55, 36 and 16%, respectively, much higher than that in general hepatitis B carriers. Univariate analysis revealed that the history of conducting paid sex for more than 12 months (P < 0.03), ear-piercing (P < 0.02), tattooing (P < 0.02), and gonorrhoea or syphilis (P < 0.005) were significant factors associated with HDV infection among these subjects. Multivariate analysis revealed that the history of ear-piercing and venereal diseases (P < 0.001) were still significant. In summary, genital ulcers caused by venereal diseases due to frequent sexual contact with multiple partners, and use of unsterilized needles in ear-piercing or tattooing play important roles in the high prevalence of HDV infection in prostitutes.

Prevalence, infectivity, and risk factor analysis of hepatitis C virus infection in prostitutes

A population of 622 prostitutes in Taiwan was tested for antibodies to the hepatitis C virus (anti-HCV) using a synthetic peptide assay composed of representative determinants from capsid and nonstructural (NS) viral proteins. Seventy-four (12%) were positive and the remaining 548 (88%) were negative. Seventy-nine samples were retested by a second-generation anti-HCV assay composed of recombinant capsid and NS proteins of HCV. Both assays had a nearly perfect agreement (Kappa value = 0.91). Of the positive cases, 31% were positive for reactivity to capsid only. Most (60/74, 81%) of the cases positive for synthetic peptide assay were HCV RNA positive, indicating potential infectivity. On the basis of the results of synthetic peptide assay, univariate analysis showed that history of paid sex for longer than 6 months, blood transfusion, acupuncture, intravenous drug abuse, and age over 20 years were significant risk factors of HCV infection (P < 0.01). Elevated alanine aminotransferase levels (> 40 U/L) were positively associated with anti-HCV, while the presence of serum hepatitis B surface antigen was a negatively associated factor. Multivariate analysis revealed that history of paid sex for longer than 6 months and blood transfusion were positively associated with anti-HCV (P < 0.001). The latter only accounted for less than one fifth of the HCV-infected prostitutes. This study indicates strongly that sexual transmission is an important route for HCV infection in prostitutes. This risk group may spread HCV to other populations as a sexually transmitted disease.

Concurrent hepatitis C virus and hepatitis delta virus superinfection in patients with chronic hepatitis B virus infection

Since hepatitis C virus (HCV) and hepatitis delta virus (HDV) are transmitted by the same routes as hepatitis B virus (HBV), simultaneous or concurrent HCV and HDV infection in patients with chronic HBV infection may occur. To test this hypothesis and to examine the clinicohistological and immunopathological presentations of such multiple hepatitis virus infections, acute and/or convalescent serum specimens from 86 patients with acute HDV superinfection were tested by enzyme immunoassay for antibodies to HCV. Of the 86 patients, 18 (20.9%) were associated with HCV infection. Although patients with early mortality cannot be evaluated by the HCV markers used in this study, the results showed that the clinical and histologic features were similar except that patients with HCV infection were older than those without HCV infection (P less than 0.01). Immunopathological studies carried out within 2 months after the onset of acute HDV superinfection demonstrated that hepatitis B core antigen (HBcAg) was not detected in any patient and HDV antigen was detected in 18.2% of the patients with HCV infection whereas HBcAg and HDAg were found in 7% and 65.1%, respectively, of those without HCV coinfection (P less than 0.02). It is concluded that concurrent HCV and HDV superinfections can and do occur in patients with chronic HBV infection. In these triple viral infections, HCV may even transiently suppress HDV and HBV.

Hepatitis D virus superinfection remains a rare occurrence in non-drug abusers in Hong Kong

Recent studies from Taiwan reported an increased prevalence of hepatitis D virus (HDV) superinfection as well as a spread of HDV infection to non-drug abusers. We examined the current prevalence of HDV superinfection in Hong Kong by testing sera from a large cohort of patients with acute and chronic hepatitis B virus (HBV) infection, collected between January 1988 and December 1990, for IgG antibody to HDV (anti-HDV). Anti-HDV was detected in 13 (93%) of 14 parenteral drug abusers who had HBV-related chronic liver disease. However, anti-HDV was detected in only one (0.15%) of 664 non-drug abusers who had chronic HBV infection and none of 31% patients with acute hepatitis B. We concluded that HDV superinfection remains a rare occurrence in non-drug abusers in Hong Kong.

Hepatitis C virus infection in patients with chronic liver diseases in an endemic area for hepatitis B virus infection

Taiwan is an endemic area for hepatitis B virus (HBV) infection, which is responsible for up to 80% of chronic liver diseases there. In contrast to an HBV carrier rate of 15-20% in the general population, only 1% of its population are seropositive for anti-HCV. To evaluate the role of HCV infection in chronic liver diseases in Taiwan, serum anti-HCV was studied using an enzyme immunoassay in 123 "healthy" administration staff of the hospital, 724 hepatitis B surface antigen (HBsAg)-positive and 157 HBsAg-negative patients with chronic liver disease. The prevalence of anti-HCV was 0.8% in the hospital staff, 24.3% in HBsAg-positive and 80.9% in HBsAg-negative patients with chronic liver diseases. Anti-HCV was positive in 10 (9.6%) of 104 HBsAg-positive and 31 (77.5%) of 40 HBsAg-negative patients with inactive chronic hepatitis; 94 (27.2%) of 346 HBsAg-positive and 53 (85.5%) of 62 HBsAg-negative patients with active chronic hepatitis; 49 (26.1%) of 181 HBsAg-positive and 33 (86.8%) of 38 HBsAg-negative patients with cirrhosis; 23 (26.7%) pf 86 HBsAg-positive and 10 (58.8%) of 17 HBsAg-negative patients with hepatocellular carcinoma. In HCV infected HBsAg-positive patients, the optical density was usually lower, and anti-HCV became negative in 27% on follow-up. HCV infection tends to occur more frequently in older, HBeAg-negative and anti-HD-positive patients with chronic HBV infection. It is concluded that HCV not only is the major agent for non-B chronic liver diseases but also plays a significant role in HBsAg-positive chronic liver diseases in Taiwan.