Familial clustering of hepatitis B infection

Cost Analysis of Single-Dose Hepatitis B Revaccination Among Infants Born to Hepatitis B Surface Antigen-Positive Mothers and Not Responding to the Initial Vaccine Series

OBJECTIVES

Infants born to mothers who are hepatitis B surface antigen (HBsAg) positive are at risk for perinatal hepatitis B infection. As prevention, these infants receive a series of 3 or 4 doses of hepatitis B vaccine starting at birth and postvaccination serologic testing. Infants with antibody levels <10 mIU/mL are considered vaccine nonresponders and should be revaccinated. The objective of this cost analysis was to assess a single-dose revaccination strategy among infant nonresponders.

METHODS

We used a decision analytic tree to compare the costs of a single-dose revaccination strategy with the costs of a 3-dose revaccination strategy. The analysis consisted of 3 epidemiologic scenarios that varied levels of previous protection among infants indicated for revaccination. We assumed health outcomes in each strategy were the same, and we evaluated costs from the societal perspective using 2016 US dollars. We conducted sensitivity analyses on key variables, including the minimum required efficacy of a single revaccination dose.

RESULTS

In all analyses, the single-dose revaccination strategy was a lower-cost option than the 3-dose revaccination strategy. Under the assumption that all revaccination visits were previously unscheduled, single-dose revaccination reduced the cost per infant by $119.81 to $155.72 (depending on the scenario). Across all scenarios, the most conservative estimate for the threshold efficacy (the minimum efficacy required to result in a lower-cost option) value of single-dose revaccination was 67%.

CONCLUSIONS

For infants who were born to HBsAg-positive mothers and who were not responding to the initial vaccine series, a single-dose revaccination strategy, compared with a 3-dose revaccination strategy, reduced costs across several scenarios. These results helped inform the Advisory Committee on Immunization Practices' vote in February 2017 to recommend single-dose revaccination.

A molecular epidemiology study investigating familial clustering of hepatitis B virus infection in families with unfavorable prognoses in Northwest China

Hepatitis B virus (HBV) infections and adverse outcome have been demonstrated to show characteristics of familial clustering. The aim of this study was to investigate the prevalence of different HBV genotypes, HBV sub-genotypes, and Pre-S mutations associated with familial HBV infection clusters with unfavorable prognoses. Families presenting with clustered HBV infections and unfavorable prognoses were enrolled in this study. Non-clustered HBV-infected individuals were used as the control group. DNA extracted from patient serum samples was used to facilitate characterization of the HBV genotypes, HBV sub-genotypes, and Pre-S mutations by phylogenetic analysis. The Pre-S/S gene was successfully amplified in 83 patients from the clustering group and 105 patients from the sporadic group. The prevalence of genotype C in the clustering group (71/83, 85.54%) was significantly higher than in the sporadic group (77/105, 73.33%) (P = 0.042). The prevalence of sub-genotype C2 in the clustering group (33/83, 39.76%) was also higher than in the sporadic group (21/105, 20%) (P = 0.003). Analyses of functional mapping of pre-S sequences showed that the prevalence of the mutation in the S promoter site (nt 3045-3189 of pre-S1 domain) was significantly increased in the clustering group compared with the sporadic group (15.7% vs. 3.8%) (P = 0.009). This study suggests that genotype C, especially sub-genotype C2, may be associated with the progression of HBV infection in familial clustering infection cohorts with unfavorable prognoses. We also observed that the natural occurrence of S promoter mutations in the clustering group was significantly prevalent.

The Role of Body Fluids in the Horizontal Transmission of Hepatitis B Virus via Household/Close Contact

Hepatitis B virus (HBV) infection commonly occurs through horizontal transmission via household/close contact. Although the body fluids of patients infected with HBV are likely to play a significant role in horizontal transmission, the precise mechanism remains unclear. In the 1970s, the infectivity of body fluids including saliva, urine, and faeces was assessed for the presence of hepatitis B surface antigen (HBsAg). Over the last decade, the HBV DNA in the body fluids of chronically infected patients was quantified using real-time polymerase chain reaction. Chimpanzee, gibbon, and chimeric mice with human livers have also been used to investigate the infectivity of body fluids. HBsAg levels, HBV DNA levels, and animal experiments have indicated that saliva and tears are able to transmit HBV. Urine and faeces do not lead to horizontal transmission. The infectivity of the remaining body fluids remains controversial. Horizontal transmission is related to both virus and host factors; thus, evaluations of HBsAg and HBV DNA levels provide insufficient data to determine the infectivity of body fluids. Universal hepatitis B vaccination has been implemented worldwide (with the exception of Northern Europe); an understanding of the role that body fluids play in horizontal transmission will contribute to the eradication of HBV.

Intrafamilial spread of hepatitis B virus in Guilan Province-North of Iran

The aim of the present study was to determine the intrafamilial spread of HBV in the family members of patients with Hepatitis B in Guilan Province, North of Iran. In a descriptive-comparative study, 156 patients with Hepatitis B, 415 family members of the index cases and 599 age and gender matched people as a control group were enrolled. Blood samples were taken from the participants and were checked for HBs Ag, HBC Ab, HBs Ab, and HBV DNA. Totally 44 (10.6%) of family members and only 1 (0.2%) of control group were HBs Ag positive (P=0.0001, OR=70.92). The overall prevalence in members of the original family was 5.3% (1.2% of the mothers, 2.2% of the brothers, 1.9% of the sisters), in sexual partners it was 1.4%, in offsprings it was 2.4% and in other households it was 1.4%. The mean age of HBs Ag positive family members was 35.3 ± 12.9 years old. Among them 27 (61.4%) were female. Only 8 (18.2%) of all HBsAg-positive reported previous HBV vaccination but just one person had the vaccine titer checked. The present survey indicates that there is a significant difference in the prevalence of Hepatitis B in the general population and family members of Hepatitis B patients and this is an evidence for horizontal transmission of HBV in household contacts.

Cross-sectional study of hepatitis B virus infection in rural communities, Central African Republic

Background

As most data on hepatitis in resource-poor countries relate to urban communities, surveys in the rural environment are necessary to determine the ‘true’ prevalence of these viral infections. We undertook a survey to determine the prevalence of hepatitis B virus (HBV) infection in an apparently healthy rural population in the Central African Republic (CAR).

Methods

The cross-sectional study was based on dried blood spots (DBS) from 273 people recruited in four prefectures (Lobaye, Nana-Mambéré, Ouham and Ouaka). Eluates from DBS were tested with commercial ELISA kits to detect markers of HBV infection. DBS were directly used for DNA extraction, followed by PCR and genotyping based on preS/S gene sequences.

Results

The overall prevalence of HBc antibodies was 27.1% (Lobaye 29%, Nana-Mambéré 28%, Ouaka 29% and Ouham 23%) and that of HBsAg was 10.6% (Lobaye 9%, Nana-Mambéré 9%, Ouaka 19% and Ouham 8%), with no statistically significant difference among the surveyed communities. Nineteen sequences obtained from 74 anti-HBc-positive patients all belonged to genotype E. Risk factor analysis of HBV infection pointed to sexual transmission of the virus.

Conclusion

The prevalence of HBV is high in rural communities in the CAR and comparable to that observed in urban areas. In addition, genotype E is prevalent in these areas. These findings underline the importance of instituting a programme of active HBV surveillance and vaccination of the population.

Seroprotection after recombinant hepatitis B vaccination among newborn infants: a review

INTRODUCTION

Hepatitis B vaccination starting at birth provides a safety net for infants exposed to hepatitis B virus (HBV) during delivery or in early life. Hepatitis B vaccine is recommended in the United States for infants prior to birthing facility discharge, and within the first 12h of life for infants born to hepatitis B surface antigen (HBsAg)-positive mothers. We performed a literature review and summarized the response to recombinant hepatitis B vaccine among infants.

METHODS

Studies published between 1987 and 2011 assessing seroprotection from recombinant hepatitis B vaccine starting within the first 30 days of life were eligible. Seroprotection was defined using an antibody to hepatitis B surface antigen (anti-HBs) threshold of 10mIU/mL at series completion. Infant seroprotection was compared in trial arms varying by maternal hepatitis B antigen status (e antigen [HBeAg], HBsAg), hepatitis B immune globulin (HBIG) administration, birth weight, vaccine dosage, schedule, and age at first dose.

RESULTS

Forty-three studies were included. The median seroprotection proportion overall was 98% (range 52%, 100%). The final median seroprotection proportions did not vary appreciably by maternal HBsAg status, HBIG administration, or schedule. Higher compared to lower dosage resulted in earlier increases in anti-HBs but not in final seroprotection proportions. Infants with birth weights <2000g compared to ≥2000g had lower median seroprotection proportions (93% and 98%, respectively). Median seroprotection proportions were also lower when infants with birth weights <2000g were vaccinated at 0-3 days of age compared to 1 month of age or older (68% versus 95%, respectively).

CONCLUSION

High levels of protection from recombinant hepatitis B vaccine are achieved in term infants vaccinated at birth, effectively preventing transmission of HBV and resultant morbidity and mortality. Implications, if any, for long-term protection are unknown for differences in responses among infants vaccinated at birth compared to ages older than 1 month.

Easy-to-use phylogenetic analysis system for hepatitis B virus infection

AIM

  The molecular phylogenetic analysis has been broadly applied to clinical and virological study. However, the appropriate settings and application of calculation parameters are difficult for non-specialists of molecular genetics. In the present study, the phylogenetic analysis tool was developed for the easy determination of genotypes and transmission route.

METHODS

  A total of 23 patients of 10 families infected with hepatitis B virus (HBV) were enrolled and expected to undergo intrafamilial transmission. The extracted HBV DNA were amplified and sequenced in a region of the S gene.

RESULTS

  The software to automatically classify query sequence was constructed and installed on the Hepatitis Virus Database (HVDB). Reference sequences were retrieved from HVDB, which contained major genotypes from A to H. Multiple-alignments using CLUSTAL W were performed before the genetic distance matrix was calculated with the six-parameter method. The phylogenetic tree was output by the neighbor-joining method. User interface using WWW-browser was also developed for intuitive control. This system was named as the easy-to-use phylogenetic analysis system (E-PAS). Twenty-three sera of 10 families were analyzed to evaluate E-PAS. The queries obtained from nine families were genotype C and were located in one cluster per family. However, one patient of a family was classified into the cluster different from her family, suggesting that E-PAS detected the sample distinct from that of her family on the transmission route.

CONCLUSIONS

  The E-PAS to output phylogenetic tree was developed since requisite material was sequence data only. E-PAS could expand to determine HBV genotypes as well as transmission routes.

Heredity, diet and lifestyle as determining risk factors for the esophageal cancer on Nanao Island in Southern China

In this case-control study we evaluated contribution of environmental and genetic factors for risk of esophageal cancer (EC) by studying populations on Nanao Island (highest risk area for EC in China) and Shanwei (low risk region). Data on lifestyle, diet and family history were collected from the 166 newly diagnosed EC patients on Nanao between 2003 and 2004, from their 1450 first degree relatives and from controls on Nanao and Shanwei. Univariate and logistic regression analysis, family aggregation patterns, standardized incidence ratio (SIR), segregation ratio and heritability index were evaluated. The family cancer history was a significant risk factor for the two scenarios; Nanao cases versus Nanao controls, and Nanao controls versus Shanwei controls. Other risk factors included smoking, alcohol and fermented fish sauce. After adjusting for confounding variables, family history was independently associated with the occurrence of EC in Nanao cases versus Nanao controls. The incidence in the first degree relatives of Nanao cases was 0.86%, significantly higher than that of the public (0.12%) and SIR value was 1.44 in the first degree relatives of the 166 EC cases. The segregation ratio was 0.11 and the heritability index among first degree relatives was 40%. Our study indicates that there are steady pathogenic risk factors in the Nanao population's lifestyle but genetic factors also play an important role for EC onset.

Molecular evidence of father-to-child transmission of hepatitis B virus

At present in Japan, only high-risk infants born to chronic hepatitis B virus (HBV)-infected mothers are given HBV vaccine. However, children can contract the virus from other HBV-infected family members, including fathers. The aim of this study is to present substantial and unequivocal evidence of father-to-child transmission of HBV infection using techniques including homology analysis and phylogenetic analysis. Thirteen chronic HBV-infected members of five families that included eight children and their respective fathers were enrolled in this study. Homology analysis and phylogenetic analyses of 2 coding region, the S gene and X gene, from the HBV genome were performed comparing the 13 nucleotide sequences from the 13 subjects. The nucleotide homology among the five sets of fathers and children was quite high (99.3-100%). A phylogenetic tree constructed on the 13 nucleotide sequences showed that all 5 sets of fathers and children were grouped into the same cluster with high bootstrap values. These results strongly indicate that father-to-child transmission is an important route of HBV infection in Japan and it is recommend that universal vaccination against HBV infection be instituted immediately in Japan for all children, in accordance with the WHO recommendation of 1997.

Intra-familial spread of hepatitis B virus infection in eastern Turkey

Hepatitis B virus (HBV) infection is a worldwide health problem. The aim of the present study was not only to determine the prevalence of HBsAg in children of HBV-infected parents but also to identify all HBSAg-positive family members to protect as many children, in the present and future, as possible. The study was carried out with the participation of 2113 family members (1205 children, 453 mothers, and 455 fathers) at Sivas SSK Hospital, Turkey. They were screened for HBV markers using standard enzyme immunoassay between September 2001 and March 2005. The prevalence of any HBV markers and HBsAg among family members of index cases was 50.5% and 30.5% respectively. HBsAg carrier rate was higher among fathers (61%) than mothers (47%), (P<0.05). The children of mother index cases had higher rates of HBsAg compared with the children of father index cases (P<0.01). Our results suggest that intra-familial childhood horizontal transmission (especially mother-to-child) is important for HBV transmission in the Turkish community, and highlights the need for screening of adult siblings and mothers of adult HBsAg carriers in addition to their spouses and children.

Intrafamilial transmission of hepatitis B in Tuzla region of Bosnia and Herzegovina

OBJECTIVE

To determine (i) the prevalence of HBV infection in families of confirmed chronic carriers, (ii) possible routes of transmission and risk factors for the intrafamilial transmission, (iii) vaccination rate among family members of chronic carriers and (iv) family members with highest risk for infection.

METHODS

A total of 172 family members of 67 hepatitis B surface antigen chronic carriers were tested for hepatitis B markers; 716 first-time blood donors from the same area were used as controls.

RESULTS

Prevalence of hepatitis B surface antigen was higher (P<0.001) among family members of index cases (12.2%; 21/172) than among controls (3.6%; 26/716) with relative risk of 3.3 (95% confidence Intervals=1.9-5.8; P<0.05). Rate of exposure among family members was 37.8% (65/172); only 8.7% (15/172) had been vaccinated for hepatitis B virus. Difference (P<0.001) in exposure existed among family members; exposure increased with age (rhos=0.34; P<0.001). Prevalences of hepatitis B surface antigen positivity and hepatitis B virus exposure were higher among parents of index cases (P<0.005) and among offspring of female index cases (P<0.001). There were more (P<0.001) hepatitis B surface antigen-positive family members among those with mother-children relationship with index case (13/31; 41.9%) than among those with father-children (19/85; 22.4%) and horizontal (siblings and spouses) relationship (2/56; 3.6%). Significantly more (P<0.001) hepatitis B surface antigen-positive and hepatitis B virus-exposed offspring were found in families where only mother was hepatitis B surface antigen positive. Among family members of HBeAg-positive cases more hepatitis B surface antigen-positive cases and hepatitis B virus-exposed cases have been found (P<0.001). Combination of HBeAg positivity and female sex of index case significantly increased risk for chronic carriage among family members (relative risk=24.06; 95% confidence interval=8.88-65.21; P<0.05).

CONCLUSION

In the area studied, both horizontal and vertical transmission exists, but maternal route is predominant. Female sex, HBeAg positivity of index carrier and presence of hepatitis B surface antigen-positive mother inside family increased risk for hepatitis B surface antigen positivity and exposure among family members. Vaccination rate of family members of index cases is alarmingly low.

Intrafamilial prevalence of hepatitis B virus in Western Brazilian Amazon region: epidemiologic and biomolecular study

BACKGROUND

Hepatitis B is endemic in the Amazon region.

METHODS

Serological markers for hepatitis B virus (HBV) were determined in 266 household members for hepatitis B surface antigen (HBsAg)-positive women (G1) and 395 household members for HBsAg-negative women (G2), randomly selected in Acre State Women's Medical Care Program, in order to evaluate the prevalence of HBV in this population. Before blood sample collection an epidemiological questionnaire was applied.

RESULTS

The overall prevalence of HBV carriers (HBsAg) and exposed individuals (anti-HBc, IgG) was, respectively, 21.1% and 60.5% in G1 and 2.8% and 27.4% in G2 (P < 0.0000001). The frequency of HBsAg was higher among siblings from group G1 (75%) compared to the absence of any HBsAg-positive sibling in G2 (P < 0.00006). The HBV markers in other family members was as follows: G1 parents, 27.3% vs 4.5% (P < 0.03), sexual partners, 21.1% vs 2.5% (P < 0.04), and offspring, 10.4% vs 1.5% (P < 0.04). A low prevalence of HBsAg and anti-HBc (IgG) was observed for the last offspring of G2 mothers compared to the high prevalence among children of G1 mothers (0% vs 18.2%, P < 0.01 and 2.3% vs 59.1%, P < 0.0000005, respectively), with children younger than 1 year being the most affected. The frequency of the habit of sharing toothbrushes and the presence of at least one HBsAg carrier were higher in G1 than in G2 (P < 0.0001 and P < 0.000002), respectively. Genotypes A, D and G were found to be predominant by Innolipa test. There were cases that reacted to more than one genotype.

CONCLUSION

Intrafamilial transmission of HBV is evident in the present study and is possibly associated with the presence of more than one HBV carrier in the family and the shared use of toothbrushes among household contacts. Genotype analysis confirms intrafamilial transmission.

Application of hepatitis B virus genotyping and phylogenetic analysis in intrafamilial transmission of hepatitis B virus

BACKGROUND

Infection with hepatitis B virus (HBV) in early life frequently results in persistent infection, and clustering of the chronic infection within a family is common. However, the relative contribution of perinatal mother-to-infant transmission or early horizontal transmission to the intrafamilial clustering of HBV infection remains unclear. Therefore, we used HBV genotyping and phylogenetic analysis to elucidate the modes of intrafamilial HBV transmission in Taiwan.

METHODS

HBV genotypes and serological markers were determined for 103 individuals from 20 families with evidence of clustering HBV infection.

RESULTS

Three patterns of intrafamilial clustering of HBV infection were identified. Among the 20 families, 8 included a hepatitis B surface antigen (HBsAg)-positive mother (pattern I), 7 included an HBsAg-positive father (pattern II), and in the remaining 5, both parents were positive for HBsAg (pattern III). The rates of HBsAg positivity for children of the 3 representative groups of families were 85.7%, 65.4%, and 87.5%, respectively (P = .16). The identical genotyping results between index parent and carrier children indicated that pattern I clustering was caused by maternal transmission, whereas pattern II clustering was caused by paternal transmission. In pattern III clustering, a concordant HBV genotype between carrier children and mother or father was found in 3 and 2 families, respectively. The modes of transmission were confirmed by phylogenetic analysis in 1 family of each pattern.

CONCLUSIONS

In Taiwan, maternal and paternal transmissions are both important in the intrafamilial spread of HBV infection.

Intrafamilial transmission of hepatitis B virus in the eastern Anatolian region of Turkey

OBJECTIVE

To determine the possible route of hepatitis B virus (HBV) transmission throughout a family setting.

METHOD

Two hundred and forty family members (42 spouses, 32 offspring, 34 mothers, 35 fathers and 97 siblings) of 84 HBsAg carriers attending the Ataturk University Medical Faculty Hospital between July 2000 and May 2001, and 384 first time blood donors (control group) were screened prospectively for markers of HBV by using an ELISA. The chi-squared and Fisher's exact tests were used for statistical analysis.

RESULTS

The prevalence of HBsAg and HBV infection among the family members (29.6% and 43.8%, respectively) was significantly higher than in the control group (9.6%, and 29.7%), P < 0.001. Among family members, the highest prevalences of HBsAg and HBV infection were in the husbands (70.0% and 90.0%, respectively), offspring (66.7% and 100.0%) of female index cases, and siblings (40.2% and 49.5%, respectively) of all index cases. Transmission of HBV to offspring was high in cases where both the parents were positive, but there was no difference in cases where only the mother or father was positive. Despite a high prevalence of HBsAg in the offspring of female index cases, HBsAg and anti-HBs seroprevalences in the mothers of index cases were not higher than the control group (P < 0.05). Thus, it appears that mothers do not have an important role in the acquisition of HBV infection.

CONCLUSION

In the area studied, in addition to the sexual route, both parents-to-child and sibling-to-sibling horizontal transmission might be the main route of intrafamilial spread of HBV infection.

Seroprevalence of Hepatitis B virus infection among an Afro-descendant community in Brazil

Furnas dos Dionísios is an Afro-Brazilian black community whose descendants were mainly fugitive slaves that established themselves in the State of Mato Grosso do Sul (MS), Brazil. The population is comprised mainly of low socioeconomic individuals who are engaged in agricultural activities. The objective of this study was to investigate the prevalence of hepatitis B (HB) and its correlation with epidemiological data obtained from the community. The studied population totaled 260 individuals with ages varying from 1 to 79 years (median 20). One hundred thirty-three (51.2%) were females and 127 (48.8%) were males. A high prevalence for anti-HBc was observed (42.7%), with present infection detected in 9.2% of the subjects who were also HB surface antigens (HBs Ag) positive; 27.3% were anti-HBc and anti-HBs reactive, and 6.2% had anti-HBc as only marker. The prevalence for anti-HBc was proportional to age, reaching its highest peak in age categories greater than 50. No serological marker was detected in children under the age of 2 years, however anti-HBc was present in 12 subjects with ages between 2 and 14 years, of these 8 (7.4%) were HBsAg positive. Among individuals over the age of 15 years, 99 were anti-HBc reactive, of these 16 (10.5%) were also HBsAg positive, thus suggesting an increased prevalence of HBV carriers among children and adolescents. The risk factors observed in this community that were significantly associated with anti-HBc positivity were age (over 20 years) and having an anti-HBc positive mother. Both HBeAg and anti-HBe were detected in 44.4% of the samples tested. HBsAg subtypes found in the studied population were adw2 (77.7%) and ayw2 (23.3%). While intrafamilial transmission was most likely responsible for HBV infection among children, other routes such as sexual contact might be considered for individuals with ages over 15 years.

Hepatitis B in the family

During a 3-year period (1992-1995), 239 index cases of hepatitis B virus (HBV) infection and 459 members of their households from the Osijek-Baranja county were examined. The aim of the study was to determine the spread of HBV infection in the families with a member verified as a virus carrier, and to identify the family members with the highest risk of infection according to kinship degrees. The retrospective and prospective methods were used in the study. The probable route of infection was assessed by the use of an epidemiologic questionnaire, and the serologic status of the study subjects concerning infection with HBV was determined by enzyme immunoassays (HBsAg, anti-HBs, anti-HBe and anti-HBc). The first member of a family identified as a virus carrier was considered an index case. HBV infection was demonstrated in 334 (47.85%) out of a total of 698 subjects. Only 21 (6.28%) of the 334 subjects with verified HBV infection developed the clinical picture of acute hepatitis B. The ratio of clinically manifest vs inapparent infection was 1:16. Serologic traces of infection were detected in 95 of the 459 family members of the index cases, yielding a mean rate of the infection among the virus carrier family members of 20.70%.

Hepatitis B in the Middle East: aspects of epidemiology and liver disease after infection

Postnatal horizontal transmission of hepatitis B virus (HBV) in early childhood seems to be the predominant method by which high hepatitis B carrier rates in the Middle East are maintained. The prevalence of hepatitis B surface antigen (HBsAg) positive status among siblings of HBV carriers is similar during childhood and adulthood, suggesting that childhood intrafamilial transmission patterns persist into adult life. There is a tendency for asymptomatic HBV carriers to have higher alanine aminotransferase (ALT) values, a feature that also tends to cluster in families. Infection in the first five years of life contributes most to the case load of chronic liver disease and thus to mortality from HBV. Mass hepatitis B immunisation programmes have been started, and while they may eventually reduce the HBV carrier state and liver disease loads significantly, prospects for total eradication of HBV in the near future are not good.

Interferon in the management of chronic hepatitis B

Many drugs have been used in the treatment of chronic hepatitis B, but with the exception of interferon, none have proved to be effective. Several studies have found that a sustained loss of viral replication occurs in approximately 40% of patients who started with a 16-week course of recombinant interferon alfa-2b given in a dose of 5 million units daily or 10 million units three times weekly. Moreover, disappearance of hepatitis B surface antigen in serum has been observed in 10-15% of treated patients. Based on these results, the Food and Drug Administration approved the use of this form of interferon in chronic hepatitis B in July 1992. This article reviews the importance of chronic hepatitis B as a health problem as well as the mechanisms of action, benefits, and adverse effects associated with interferon. Particular emphasis is given to the safety and efficacy data for recombinant interferon alfa-2b.

Chronicity rate of hepatitis B virus infection in the families of 60 hepatitis B surface antigen positive chronic carrier children: role of horizontal transmission

It is known that the 5%-10% of adults infected with hepatitis B virus (HBV) develop a chronic infection and that HBV infection acquired at birth by an hepatitis B surface antigen (HBsAg)/hepatitis B "e" antigen (HBeAg)-positive mother almost invariably leads to chronic infection. Little information is, however, available about the risk of HBV infection acquired in childhood becoming chronic. We have, therefore, studied the chronicity rate of HBV infection in the families of 60 consecutive HBsAg-positive chronic carrier children. Of parents 81.5% and 78.6% of children showed serological evidence of past or ongoing HBV infection. The chronicity rate was significantly higher among children (73.4%) than parents (35.6%). Such a high chronicity rate in these children was not correlated with vertical transmission, since this was reported in only 1.7% of them. It is noteworthy that the chronicity rate of HBV infection was not significantly different between children of HBsAg-positive mothers and those in whom infection must have been horizontally transmitted because their mothers were HBsAg-negative. Although the families studied represent a selected sample and the role of genetic factors could not be excluded, our results seem to show that the most important factor in determining the outcome of infection is the acquisition of hepatitis B during childhood.

Intrafamilial transmission of hepatitis C virus in Japan

To study the intrafamilial transmission of hepatitis C virus (HCV), 36 family members of 16 patients with anti-HCV (anti-C100-3)-positive chronic liver disease were screened for anti-HCV by an enzyme-linked immunosorbent assay (ELISA). Clusters of anti-HCV-positive individuals were observed in 2 of 16 families (12.5%). Four of 35 family members (11.4%) with no history of blood transfusion were positive for anti-HCV. Two of 17 offspring (11.8%) of anti-HCV-positive females were positive for anti-HCV, while 1 of 5 spouses (20.0%) was positive for anti-HCV. These data suggest that intrafamilial transmission is one of the possible routes of infection for HCV.

Therapeutic advances in the prevention of hepatitis B: yeast-derived recombinant hepatitis B vaccines

Viral hepatitis is second to gonorrhea as the most commonly reported infectious disease in the US. Hepatitis B accounts for the majority of viral hepatitis cases. Fortunately, the disease is self-limiting and frequently resolves completely with minimal complications; however, a significant number of individuals may experience long-term sequelae. Research utilizing genetic engineering has led to the development of yeast-derived recombinant DNA (YDR) hepatitis vaccines--a significant advancement in the control and prevention of hepatitis B. The recombinant process allows production of unlimited quantities of vaccine at considerably lower cost and without the potential threat of blood-borne illness. Clinical trials in various high-risk populations have demonstrated the effectiveness and safety of YDR vaccines. However, questions regarding optimal regimen and the need for periodic revaccination remain unanswered. Persons at risk should be adequately vaccinated against hepatitis B.

Morbidity and mortality from chronic hepatitis B virus infection in family members of patients with malignant and nonmalignant hepatitis B virus-related chronic liver diseases

Three-hundred forty-one HBsAg-positive family members of 152 patients with chronic hepatitis B virus infection (47 asymptomatic carriers, 59 with chronic hepatitis, 17 with cirrhosis and 29 with hepatocellular carcinoma) were prospectively studied to determine the morbidity and mortality from chronic hepatitis B virus infection in the family members of patients with malignant and nonmalignant hepatitis B virus-related chronic liver diseases. Most of the family members had no history of acute hepatitis, were asymptomatic and were unaware of their carrier status. However, 5.3% had stigmata of chronic liver disease, 6% had serum ALT levels that exceeded two times the upper limit of normal and 78% of those who had biopsies had chronic hepatitis with or without cirrhosis. During a follow-up period of 12 to 90 mo (median = 39 mo), 3% had symptoms of chronic liver disease; 24% had transient, recurrent or persistent elevation in serum ALT levels, 1.4% had cirrhosis and 1% had hepatocellular carcinoma. Neither hepatocellular carcinoma in the index patient nor a previous history of hepatocellular carcinoma in the family was associated with an increase in the morbidity and mortality from chronic hepatitis B virus infection in the HBsAg-positive family members.

The emergence of hepatitis B as a sexually transmitted disease

In the United States, approximately 300,000 cases of hepatitis B virus infection occur annually, and heterosexual activity is one of the most commonly reported risk factors for acquiring disease. Until the number of infections transmitted through heterosexual contact can be reduced through hepatitis B vaccination, there is little chance of controlling this infection.

A dynamic study of the intrafamilial spread of hepatitis B virus infection: relation with the viral replication

A total of 848 household contacts of 285 hepatitis B surface antigen (HBsAg) chronic carriers were included in a prospective study. Of the total number of contacts negative for hepatitis B virus (HBV) markers at baseline, 330 relatives of 145 HBsAg carriers were observed over a mean period of 20.1 months. Among all household contacts, 284 (33.5%) were found positive for at least one HBV marker. The prevalence of HBV markers was significantly higher among the contacts of more than one HBsAg carrier (75.9%) than among those with only one (26.0%) (P less than .001). The presence of hepatitis B e antigen (HBeAg), specific HBV-DNA polymerase (HBV-DNAp), HBV-DNA, and polymerized human serum albumin (pHSA-R) in the index case was associated with a significantly higher incidence of HBV markers among household contacts. During the follow-up, the number of household contacts initially negative for HBV markers who became infected was found to be in direct relation to the presence of HBeAg, HBV-DNAp, HBV-DNA and pHSA-R in the index case.

Hepatitis B infection in Vanuatu: age of acquisition of infection and possible routes of transmission

Seroepidemiological studies of hepatitis B were carried out on diverse groups of children (477) and adults (629) from the Pacific Island country of Vanuatu. In children under 14 years, prevalences of HBsAg and of all markers were 6% and 53.3% respectively; in adults greater than or equal to 20 years the prevalences were 15% and 70%. Age specific prevalence of hepatitis B infection (all markers) was low in infancy (less than 1 year) but rose sharply afterwards, suggesting that the main mechanism of transmission was horizontal spread. This finding is consistent with other developing country studies from the Pacific Islands and elsewhere. In view of the main ages and mechanisms of transmission of hepatitis B in children in developing countries and the need for simple and inexpensive immunisation strategies in this context, it is recommended that mass vaccination of all infants with hepatitis B vaccine be undertaken in hyperendemic areas.

Horizontal transmission of hepatitis B virus

Meta-analysis of seroprevalence surveys shows that horizontal transmission of hepatitis B virus (ie, that occurring without apparent parenteral, sexual, or perinatal exposure) is common in areas endemic for the virus. It occurs especially in pre-adolescent children. In developed countries, where endemicity of hepatitis B virus is low, horizontal transmission (probably via saliva or open wounds) may occur in households with a persistent carrier, but it is less efficient a means of infection than is sexual or perinatal transmission. Horizontal transmission also seems possible in pre-school day-care centres in developed countries, despite the small numbers of carriers in such places.

Seroepidemiologic study of adult T-cell leukemia virus (ATLV) and hepatitis B virus infection in Okinawa, Japan

A total of 2,283 serum samples were collected from healthy subjects in three islands of the Yaeyama district of Okinawa, Japan. These sera were tested for the presence of hepatitis B surface antigen (HBsAg), for antibody to hepatitis B core antigen (anti-HBc), and for antibody to adult T-cell leukemia-associated antigen (anti-ATLA). Correlation between hepatitis B virus infection and adult T-cell leukemia virus (ATLV) infection was determined by using the prevalence rates for three virus markers. Overall prevalence of HBsAg, anti-HBc and anti-ATLA was 6.5%, 57.4%, and 17.9%, respectively. Age-specific prevalence of anti-HBc and anti-ATLA increased with age, but that of HBsAg did not. Sex-specific prevalence of HBsAg was significantly higher in males than in females, but that of anti-ATLA was significantly higher in females than in males. Statistical analysis revealed that prevalence of anti-ATLA was significantly higher in HBsAg-positive persons and HBsAg-negative/anti-HBc-positive persons than in those negative for HBsAg and anti-HBc. These data suggest that hepatitis B virus-infected persons have a significantly higher chance of adult T-cell leukemia virus infection than those without hepatitis B virus infection in the area studied.

The hazard of infection from the shared communion cup

Interest and concern that the shared communion cup may act as a vehicle for indirectly transmitting infectious disease was reawakened when the human immunodeficiency virus (HIV) was detected in the saliva of infected persons. Bacteriological experiments have shown that the occasional transmission of micro-organisms is unaffected by the alcoholic content of the wine, the constituent material of the cup or the practice of partially rotating it, but is appreciably reduced when a cloth is used to wipe the lip of the cup between communicants. Nevertheless, transmission does not necessarily imply inoculation or infection. Consideration of the epidemiology of micro-organisms that may be transmitted via saliva, particularly the herpes group of viruses, suggests that indirect transmission of infection is rare and in most instances a much greater opportunity exists for direct transmission by other means. There is substantial evidence that neither infection with hepatitis B virus nor HIV can be transmitted directly via saliva so that indirect transmission via inanimate objects is even less likely. No episode of disease attributable to the shared communion cup has ever been reported. Currently available data do not provide any support for suggesting that the practice of sharing a common communion cup should be abandoned because it might spread infection.

A study of sister-chromatid exchange in peripheral lymphocytes of hepatitis B patients with HBsAg positive and their children

Previous studies of sister-chromatid exchange (SCE) in patients with hepatitis B have been reported. But as far as we know, no such work has been done in children born to parents with hepatitis B, either one or both of whom are infected. In the present study, frequencies of SCE in the peripheral lymphocytes of 30 hepatitis B parents with hepatitis B surface antigen (HBsAg) positive and 40 of their children were observed. SCE frequencies of 20 normal adults and 3 normal children were analysed for comparison with the patients and their children. The results obtained from all of the samples were as follows: The hepatitis B patients with HBsAg positive had a significantly higher SCE frequency than the normal adults (P less than 0.01); the children born after their parents contracted hepatitis B had a significantly higher SCE frequency than normal children (P less than 0.01); there was no significant difference in SCE (P greater than 0.05) between children born after their parents contracted hepatitis B, children born after their mothers acquired it and children born after their fathers acquired it. The above results indicate that hepatitis B patients with HBsAg positive and their children born after they contracted hepatitis B had significantly higher frequencies of SCE; these data might throw new light on the study of genetic factors acting on the mechanism of hepatitis B.

Epidemiologic study of hepatitis B in pregnant Korean women

The positive rates of hepatitis B viral markers according to many epidemiologic factors were analyzed in 2,873 pregnant women who delivered at St. Columban’s Hospital in Mokpo City from April 1st, 1985 to March 31st, 1986.

The following results were obtained: The overall HBsAg positivity in all pregnant women was 8.3%. The positive rate of HBsAg was unrelated to age. It was 13.2% in the 11–20 year age group. 12.5% in the 31–40 year age group, 7.8% in the 21–30 year age group and 0.0% in the 41–50 year age group. The positive rate of HBsAg was slightly related to locality. It was a little higher in women who grew up in rural areas (8.6%) than in urban areas (7.7%). The positive rate of HBsAg was unrelated to educational background. The positive rate of HBsAg was unrelated to economic status. It was 8.7% in the highest income group and 8.6% in the lowest income group. The positive rate of HBsAg was higher in cases who had injections more than four times. The positive rate of HBsAg was higher, but not significantly, in cases who had received blood transfusion. The positive rate of HBsAg was higher, but not significantly, in cases who had more than three siblings (0.05

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Clinical approach to viral hepatitis in homosexual men

The prevalence of both hepatitis A and hepatitis B is increased in homosexual men. On an annual basis, 5% to 7% of homosexual men will acquire hepatitis A. Risk factors for HAV infection include length of homosexual activity, number of sexual contacts, and oral--anal sexual contact. The HBsAg carrier rate of homosexual men is 5% to 6%, and another 50% have evidence of previous HBV infection with a positive anti-HBs. HBeAg is present in a higher precentage of HBsAg-positive homosexual men (38% to 75%) than in general population carriers (3% to 30%). The annual incidence for HBV infection in homosexual men is 16% to 28%, higher than that for hepatitis A. Transmission of HBV infection in homosexual men is facilitated by a large number of sexual partners, high HBsAg carrier rate, high infectivity of carriers (positive HBeAg), and the specific sexual practices of oral--anal and anal--genital contact with exposure to HBV on open mucosal surfaces. The prevalence of non-A, non-B and delta infection in homosexual men is probably somewhat increased, but the importance of these viruses in the development of hepatitis in this population remains uncertain. Prevention of hepatitis A and B in homosexual men will ultimately be achieved by vaccination of susceptible individuals, which currently is feasible only for hepatitis B. Appropriate use of immune globulins for postexposure prophylaxis and knowledge of specific sexual practices that transmit disease may reduce the incidence of hepatitis A and B.

Lack of transmission of HTLV-III/LAV infection to household contacts of patients with AIDS or AIDS-related complex with oral candidiasis

To determine the risk of transmission of human T-cell lymphotropic virus Type III/lymphadenopathy-associated virus (HTLV-III/LAV) to close but nonsexual contacts of patients with the acquired immunodeficiency syndrome (AIDS), we studied the nonsexual household contacts of patients with AIDS or the AIDS-related complex with oral candidiasis. Detailed interviews, physical examinations, and tests for serum antibody to HTLV-III/LAV were performed on 101 household contacts of 39 AIDS patients (68 children and 33 adults), all of whom had lived in the same household with an index patient for at least three months. These contacts had shared household items and facilities and had close personal interaction with the patient for a median of 22 months (range, 3 to 48) during the period of presumed infectivity. Only 1 of 101 household contacts--a five-year-old child--had evidence of infection with the virus, which had probably been acquired perinatally rather than through horizontal transmission. This study indicates that household contacts who are not sexual partners of, or born to, patients with AIDS are at minimal or no risk of infection with HTLV-III/LAV.

Chemical liver function tests and epidemiologic studies of HBsAg positive blood donors

The HBsAg positivity in age, sex, occupation, blood type, past history and chemical liver function tests were analyzed in 869 cases without symptoms of liver disease and positive testing for HBsAg by RPHA method, who were selected among 11, 197 blood donors of the Red-Cross Blood Bank in Pusan, Korea from August 1, to September 30, 1982. The following results were obtained: 1. The overall HBsAg positivity in random blood donors was 7.76%. 2. The HBsAg positivity of males was 8.36% and females 6.0%; males had a slightly higher positivity than females. 3. The HBsAg positivity of the 16–20 year old age group had the highest frequency (9.05%), 21–25 year old age group 8.23%, 26–30 year old age group 5.72%, 31–35 year old age group 5.76%, 36–40 year old group 5.85%, 41–45 years old age group 4.76%, and 46–50 year old age group 3.7%. HBsAg positivity had decreasing tendency of frequency by increasing age. 4. The HBsAg positivity of the merchant group had the highest frequency (10.26%), and next, the unemployed, salary man, student, soldier, in order of frequency. 5. The HBsAg positivity in cases with blood type A had the highest frequency (8.07%), and next, cases with B type, O type, and AB type in order of frequency. 6. The HBsAg positivity in cases with no past history in liver disease had the highest frequency (75.37%), and next, cases with history of liver diseases among family 12.54%, hepatitis with jaundice 5.06%, admission due to other diseases except liver diseases 3.57%, transfusion 2.42%, hepatitis without jaundice 1.04%. 7. In chemical liver function tests of HBsAg positive blood donors, elevation of SGPT level showed highest frequency (10.70%), SGOT 7.7%, total serum bilirubin 5.29% and elevation of one or more than of SGPT, SGOT, total serum bilirubin 18.99%.

Large-scale survey of hepatitis B virus infection in families

To investigate HBV transmission in families on three islands in Okinawa, Japan, prevalence of HBV markers in two groups of inhabitants was determined. One group consisted of members of families in which there was at least one HBsAg carrier (carrier families); the other group consisted of members of families in which there were no HBsAg carriers (non-carrier families). A total of 3,261 serum samples were collected from subjects on Iriomote Island, Hateruma Island, and Yonaguni Island. These samples were tested for HBsAg by reversed passive hemagglutination (RPHA) and for antibody to hepatitis B core antigen (anti-HBc) by radioimmunoassay. Overall prevalences of HBsAg and anti-HBc were 8.2 and 65.8 per cent respectively. The prevalence of anti-HBC among members of carrier families (80.8%) was significantly higher than that among members of non-carrier families (61.6%) (P less than 0.001). The prevalence of anti-HBc among members of carrier families was higher in all age groups, and was particularly so in children. Within carrier families, the prevalence of anti-HBc was significantly higher in families in which there was at least one HBsAg carrier with HBeAg (94.5%) than in families with no HBeAg-positive carriers (76.1%). This difference was especially marked in young children. These data suggest that in families with HBsAg carrier(s), the risk of transmitting HBV to members, particularly to young children, is higher than in families without carriers, and that the risk is further increased in families with HBeAg-positive carrier(s).

Structural analysis of hepatitis B surface antigen by monoclonal antibodies

A method has been developed for the analysis of hepatitis B surface antigen (HBsAg) antigenic structure at the molecular level that creates "fingerprints" or "signatures" of various hepatitis B viral (HBV) strains. This technique employs high affinity IgM and IgG monoclonal antibodies (anti-HBs) directed against distinct and separate determinants on HBsAg. In performing this antigenic structural analysis, separate binding curves for different monoclonal anti-HBs are generated by measuring immunoreactivity in serial dilutions of HBsAg-positive serum by radioimmunoassay. Since the HBsAg concentration in serum is unknown, the binding profiles of groups of samples are aligned by an iterative least-squares procedure to generate the numerical signature characteristic of the viral strain. The numerical signatures are then displayed on a computer-graphic plot. The signature profiles of HBsAg subtypes are a true reflection of their antigenic structure, and in vertical and horizontal transmission studies the molecular characteristics of the viral epitopes are conserved. By signature analysis we found substantial antigenic heterogeneity among the ayw3 strain both in the U.S. and France, as well as in populations of the Far East and Africa. Populations in Ethiopia, Gambia, and the Philippines were infected with two antigenically distinct HBV strains. In some newly identified HBV strains, it was found that epitopes identified by some monoclonal antibodies were absent or substantially reduced, which suggested that a genetic mutation may have occurred. Thus this study suggests that there is far more antigenic heterogeneity in HBV than previously recognized. These variants are antigenically distinct from each other at the epitope level, and were heretofore unrecognized by polyvalent anti-HBsAg antibodies.

Hepatitis B infection in households of acute cases

Seroepidemiological studies conducted in 369 household contacts of 80 acute cases of hepatitis B in Singapore showed that asymptomatic chronic carriers of hepatitis B surface antigen (HBs Ag) are the main source of acute hepatitis B infection. The HBs Ag prevalence rate in asymptomatic household members was 20% compared with a 6% prevalence for the general population. The majority of the household carriers (60%) were highly infectious with positive hepatitis e antigen (HBe Ag). The overall prevalence of HBV infection (with at least one HBV marker) of the household contacts was 40.7%. Spouses and parents of acute cases had a significantly higher prevalence of HBV infection than other members of the families. HBV prevalence rate showed no association with the household size. Factors associated with the risk of transmission of HBV infection included sharing of various personal and household articles, such as toothbrush, towel, handkerchief, clothing, razor, comb, bed and bedding. Sleeping in the same bedroom, eating together at meals, and sharing of eating and drinking utensils were not associated with an increased risk of transmission of infection. Follow-up studies six months later showed that 30% of the acute cases became chronic HBs Ag carriers (with 46% HBe Ag positive), thus providing an additional source of infection in the families, while 8% of the susceptible household members acquired asymptomatic HBV infection. Health education on the prevention of HBV transmission in the homes of acute cases should be based on sound epidemiological information. Household contacts of acute cases of hepatitis B should be routinely screened and the susceptible vaccinated against the disease as soon as possible.

Familiar clustering and spreading of hepatitis delta virus infection

The prevalence of hepatitis delta virus (HDV) infection was significantly higher among the relatives of 79 carriers of HBsAg with antibody to HDV (index cases) than among relatives of 111 carriers without serological evidence of HDV infection (controls). Antibody to HDV was found in 45 of the 80 (56%) carriers of HBsAg in families of index cases but only in 2 of 59 (3%) carriers in families of controls (P less than 0.0001). During follow-up new HDV infection developed in 31% of 13 susceptible carriers in families of index cases, but only in 1.2% of 162 susceptible carriers in families of controls (P less than 0.001). None of the family members previously unexposed to the hepatitis B virus had HDV markers in serum or developed this infection during the follow-up. Familial clustering shows that HDV is transmitted by personal contacts, presumably through the inapparent permucosal or percutaneous passage of virus during close or intimate contact. The family model indicates that endemic HDV is maintained and spread through the network of carriers in the community, and that HBsAg carriers in contact with HBsAg/HDV carriers are at high risk of contracting HDV.

Indications for use of hepatitis B vaccine, based on cost-effectiveness analysis

To formulate indications for the use of hepatitis B vaccine, we examined the cost effectiveness of three strategies: vaccinating everyone; screening everyone and vaccinating those without evidence of immunity; and neither vaccinating nor screening, but passively immunizing those with known exposure. Estimates of the hepatitis attack rate, prevalence of immunity, and frequency of known exposure were made for three representative populations: homosexual men, surgical residents, and the general population of the United States. Screening followed by vaccination of homosexual men and vaccination without prior screening of surgical residents would result in savings of medical costs. Neither screening nor vaccination is the lowest-cost strategy for the general population. Vaccination of susceptible persons will save medical costs for populations with annual attack rates above 5 per cent. Vaccination may be considered cost effective (or cost saving when indirect costs are included) for populations with attack rates as low as 1 to 2 per cent.

Primary hepatocellular carcinoma in Alaskan natives, 1969-1979

The records of 20 Alaskan Native patients with primary hepatocellular carcinoma (PHC) diagnosed in the 11-year period 1969-1979 were reviewed. The annual incidence of PHC was found to be high among Alaskan Native males and especially high among Alaskan Eskimo males (7.6 and 11.2 per 100,000 respectively) in comparison to Greenland and Canadian Eskimos and US white males. Familial and geographic clustering of PHC patients was noted in areas known to be hyperendemic for hepatitis B virus (HBV) infection. A bimodal age distribution among PHC patients occurred with peaks at 15-25 years and 40-65 years. A high prevalence of hepatitis B surface antigen (HBsAg) in serum of patients in the younger age group suggests that HBV infection might be a factor associated with the development of PHC in young Eskimos. PHC in Alaskan Natives is apparently not closely associated with alcoholic cirrhosis.