Horizontal Transmission Of Hepatitis B Virus Research Articles

Hepatitis B Virus Prevalence and Transmission in the Households of Pregnant Women in Kinshasa, Democratic Republic of Congo.

The World Health Organization Africa region has high regional hepatitis B virus (HBV) prevalence, and evidence suggests more frequent horizontal HBV transmission than other regions. Context-specific epidemiological studies are needed to inform additional HBV prevention measures. In the cross-sectional Horizontal and Vertical Transmission of Hepatitis B (HOVER-HBV) study, we introduced HBV surface antigen (HBsAg) screening alongside existing HIV screening as part of routine antenatal care in high-volume maternity clinics in Kinshasa, Democratic Republic of Congo. We recruited households of pregnant women ("index mothers") who were HBsAg-positive and HBsAg-negative, defining households as index-positive and index-negative, respectively. Household members underwent HBsAg testing and an epidemiological survey. We evaluated HBsAg prevalence and potential transmission correlates. We enrolled 1006 participants from 200 households (100 index-positive, 100 index-negative) across Kinshasa. HBsAg-positivity prevalence was more than twice as high in index-positive households (5.0% [95% confidence interval {CI}, 2.8%-7.1%]) as in index-negative households (1.9% [95% CI, .6%-3.2%]). HBsAg-positivity prevalence was 3.3 (95% CI, .9-11.8) times as high among direct offspring in index-positive versus index-negative households. Factors associated with HBsAg positivity included older age, marriage, and having multiple recent partners or any new sexual partners among index mothers; and older age, lower household wealth, sharing nail clippers, and using street salons among offspring in index-positive households. Vertical and horizontal HBV transmission within households is ongoing in Kinshasa. Factors associated with infection reveal opportunities for HBV prevention efforts, including perinatal prevention, protection during sexual contact, and sanitation of shared personal items.

Horizontal Modes of Transmission of Hepatitis B Virus (HBV): A Systematic Review and Meta-Analysis.

Horizontal transmission of hepatitis B virus (HBV) is a significant transmission route in households, among contact sport athletes and institutionalized individuals. Children often are infected by non-sexual close contacts with an increased tendency to become chronic carriers. Hence, the awareness about various high-risk behaviours leading to horizontal transmission in the community is essential. A systematic review and meta-analysis was carried out to assess quantitatively the pooled prevalence of horizontally transmitted HBV infection globally. The study was started after ruling out registered or ongoing systematic reviews related to this topic in the PROSPERO database. The study protocol was documented in PROSPERO with a registration number CRD42021235165. We searched electronic databases for published articles in English between 1981 and April 2021 reporting horizontal modes of hepatitis B transmission among unvaccinated contacts. Meta-analysis was carried out in STATA version 13.0 (College Station, Texas 77,845 USA). The forest plots were constructed using metaprop package in STATA. Forty-one studies were systematically reviewed and 15 studies were qualified for the meta-analysis, including 1619 hepatitis B cases and 4869 contacts. The overall pooled prevalence of horizontally transmitted HBV infection among the contacts was 38% (95% CI 30%-46%). The pooled prevalence among 3,912 household contacts from nine qualified studies was estimated as 44% (95% CI 35%-54%). The pooled prevalence rates among institutionalized individuals and contact sport athletes were 30% (95% CI 23%-37%) and 18% (95% CI 5%-32%), respectively. The likelihood of horizontal transmission of HBV is greater among household contacts of chronic carriers of HBV and institutionalized individuals.

Hepatitis B and HIV coinfection in Northern Uganda: Is a decline in HBV prevalence on the horizon?

The available data concerning hepatitis B virus (HBV) infection in Uganda are limited, particularly in the case of people living with HIV/AIDS (PLWH). HBV is not routinely tested when starting antiretroviral therapy (ART). We aimed to determine the prevalence, the correlates of the risk of HBV infection, and the association with outcomes of ART among PLWH attending a busy HIV clinic in a referral hospital in Northern Uganda. From April to June 2016, a random sample of 1000 PLWH attending the outpatients' clinic of St. Mary's Hospital, Gulu, Uganda were systematically selected to undergo a rapid hepatitis B surface antigen (HBsAg) test after administering a questionnaire in this cross-sectional study. HIV care parameters were obtained from client files. Multivariate logistic regression and general linear model were used for the analysis. 950 of the 985 evaluable patients (77% females; mean age 42.8 years) were receiving ART. The overall prevalence of HBsAg was 7.9% (95% confidence interval [CI] 6.2-9.6%), and was significantly lower among the females (6.8% vs 11.7%; p = 0.020). The factors independently associated with higher HBV infection were having lived in an internally displaced persons' camp (adjusted odds ratio [aOR] 1.76, 95% CI 1.03-2.98; p = 0.036) and having shared housing with HBV-infected people during childhood (aOR 3.30, 95% CI 1.49-7.32; p = 0.003). CD4+ T cell counts were significantly lower in HBV patients (p = 0.025), and co-infection was associated with a poorer CD4+ T cell response to ART (AOR 0.88; 95% CI 0.79-0.98; p = 0.030). The observed prevalence of HBV among the PLWH may be underestimated or a signal of HBV decline in the region. The factors favouring horizontal HBV transmission identified suggest extending HBV screening and vaccine prophylaxis among PLWH.

Hepatitis B virus detected in paper currencies in a densely populated city of India: A plausible source of horizontal transmission?

BACKGROUNDThe recent rise in the incidence of hepatitis B virus (HBV) infections in a densely populated city of eastern India (“mixing vessel” of people of varied socio-economic and immune status) prompted this study. Applying saliva on fingers for enumerating bank notes is a common practice in the Indian subcontinent. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin. AIMTo investigate whether paper currencies could be a plausible mode of horizontal transmission of HBV infection.METHODSPolymerase chain reactions (PCR) followed by nucleotide sequencing was done for the detection of HBV. Hepatitis B virus surface antigen enzyme-linked immunosorbent assay(HBsAg ELISA) was performed on all HBV deoxyribonucleic acid-positive samples to check the detectability of the virus. Atomic force microscopy (AFM) was carried out for visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings.RESULTSHBV-specific PCRs on pellets obtained after ultracentrifugation/ immunoprecipitation of the currency paper washings detected potentially intact/viable HBV (genotype D2) in 7.14% of samples (n = 70). AFM gave the visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings. However, HBV isolates from the currency notes could not be detected by HBsAg ELISA.CONCLUSIONIt is a common practice in the Indian subcontinent to count paper currencies by applying saliva on fingertips. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin, but it was practically not possible to demonstrate experimentally such transmission. Detection of potentially intact/viable and “occult” HBV from currency poses potential risk of silent transmission of this virus among the general population.

Prenatal hepatitis B screening and associated factors in a high prevalence district of Lira, northern Uganda: a community based cross sectional study

BackgroundChronic hepatitis B Virus (HBV) infection affects 80–100 million people in sub-Saharan Africa and accounts for an estimated 650,000 deaths annually. The prevalence of active hepatitis B virus infection among women aged 15–64 in mid-Northern Uganda is about 5%. Lira district is among the high prevalence areas where government embarked on mass HBV screening since 2015 as a gateway for access to prevention, treatment services, and an effective response to the hepatitis B epidemic. The current proportion of pregnant women screened and the factors associated with prenatal HBVscreening in Lira are not known despite the fact that women contribute largely to both vertical and horizontal transmission of HBV. This study aimed at determining the proportion of pregnant women screened for HBV and factors associated with prenatal HBV screening in Lira district.MethodsThis was a community based cross sectional study conducted among 423 pregnant women in the sub counties of Aromo and Agweng in Lira district. Data were collected using open data kit and analysed using STATA version 14. The outcome variable was prenatal HBV screening while predictor variables were community, individual and health facility factors associated with HBV screening. Multivariable logistic regression was used to determine factors associated with prenatal HBV screening.ResultsThirty five women (8.3%) had been screened for HBV during the current pregnancy. Factors associated with prenatal HBV screening in Lira included perceived risk (Adjusted Odds Ratio (AOR) 3.78, 95% CI 1.01–6.14), respondent’s age (AOR = 3.98, 95% CI 1.39–5.09), husband/partner’s education (AOR = 3.34, 95% CI 1.10–5.12) and past failure to access to HBV screening services at government health facilities (AOR = 6.44, 95% CI 2.10–8.02).ConclusionThe level of HBV screening among pregnant women in Lira was low and is mainly associated with perceived risk, age, access to HBV screening services and spousal education level. More effort is needed in creating mass awareness on the need and importance of HBV screening most especially among pregnant women.

Occult Hepatitis B Virus Infections (Often with Human Herpesvirus 7 Co-Infection) Detected in Pityriasis rosea Patients: A Pilot Study.

Background:The etiopathogenesis of Pityriasis rosea (PR), a papulo-squamous skin disease, remains elusive and hypothesized to be caused primarily by human herpesvirus (HHV) 6 or 7 or immune dysfunction.Aims:The recent increasing incidences of hepatitis B virus (HBV) infections, including asymptomatic occult HBV infections (OBIs), in a densely populated city in India, prompted us to investigate whether PR patients (from varied socioeconomic and immune status) harbor the underlying HBV infections. These cases were also investigated for HHV 6 and 7 infections.Materials and Methods:DNA from ethylenediaminetetraacetic acid blood samples from PR-diagnosed individuals (n = 13; mostly young adults) and healthy controls (n = 11) were subjected to virus gene-specific polymerase chain reactions (PCRs) for HBV and HHV 6 and 7. PCR products of expected length, when observed, were sequenced (bidirectional) using overlapping primers. Sequences were identified by NCBI BLAST and analyzed by multiple sequence alignment and phylogenetic studies. The blood samples were tested for HBsAg by EIA.Results:In 5/13 PR samples, only HBV DNA (4/5 being HBsAg negative) was detected, providing first-time evidence that PR may be manifested in asymptomatic HBV carriers. 6/13 cases were HHV 7 (not HHV 6) DNA positive, providing confirmatory molecular genetic evidence for the first time of PR association with HHV 7 from India. Surprisingly, 5/6 HHV 7-positive PR cases were also HBV positive. Overall, 10/13 PR samples showed evidence of HBV infection. 8/13 were OBI, harboring at least one OBI-signature S protein mutation. All healthy controls were HBsAg EIA and PCR negative.Conclusions:77% of PR patients presented the evidence of underlying HBV infection (genotype D2), suggestive of horizontal HBV transmission. This warrants for mass HBV vaccination. PR patients should be tested for underlying virus infections for appropriate therapy and management.

Seroprevalence, genotypic distribution and potential risk factors of hepatitis B and C virus infections among adults in Siem Reap, Cambodia.

We investigated hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among adults in Siem Reap, Cambodia, to consider the prevention strategy in cooperation with the Ministry of Health in Cambodia. Serological tests for determining HBV and HCV infections and questionnaires were performed from 2010 to 2012 among the general population in the province of Siem Reap. Multivariate logistic regression analysis was conducted to clarify the factors related to HBV and HCV infections. There were 483 participants, comprising 194 men and 289 women (age range, 18-89 years). The prevalence of hepatitis B surface antigen was not very high at 4.6%, while anti-hepatitis B core (anti-HBc) was high at 38.5%. All HBV DNA samples were classified as genotype C. Anti-HBc showed the trend that the older the age, the higher the positive rate (P = 0.0002). The prevalence of HCV RNA and anti-HCV were 2.3% and 5.8%, respectively. HCV RNA was detected in 39.3% of anti-HCV positive samples and most of them were classified as genotype 6 (54.5%) and 1 (27.3%). Remarkably, in multivariate logistic regression analysis, history of operation and blood transfusion were significantly associated with the positivity for HBV infection and HCV RNA, respectively. Our results showed that operation and blood transfusion were potential risk factors for HBV and HCV infection, respectively, and supposed that horizontal HBV transmission may be frequent in adults in Cambodia. Hence, for reducing HBV and HCV infections, it is necessary to improve the safety of blood and medical treatment.

High prevalences of hepatitis B and C virus infections among adults living in Binh Thuan province, Vietnam.

Vietnam is one of the countries with the highest mortality from liver cancer, which is mostly attributed to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. For planning preventive strategies against these infections, we investigated prevalences of HBV and HCV infections among adults living in Binh Thuan, Vietnam. Our study consisted of a serological survey for HBV and HCV infections and a questionnaire survey on their risk factors. The sample size was calculated based on anticipated rate of hepatitis B surface antigen (HBsAg). Subjects were randomly sampled using a multistage method. Confirmation and family-tree surveys were conducted to examine persistent HBV infection and intrafamilial HBV transmission, respectively. A total of 509 adults, comprised of 230 men (45.2%) and 279 women (54.8%), were enrolled. Prevalences of HBsAg, hepatitis B surface antibody and hepatitis B core antibody were 15.3%, 60.3% and 71.7%, respectively. Most HBV DNA positive sera were classified as genotype B (75.3%) and C (11.7%). Of HBsAg positive subjects, 96.7% were persistently infected and one acutely HBV infected person was identified. Family-tree surveys suggested that horizontal extrafamilial HBV transmission might have been frequent. Prevalences of anti-HCV and HCV RNA were 3.3% and 1.8%, respectively. HCV genotype 6a was prominent (55.6%). In Binh Thuan, prevalences of HBV and HCV infections are high, HBV genotype B and HCV genotype 6a are predominant, and horizontal HBV transmission may still occur. Therefore, raising the coverage of a universal HBV vaccination program may be an effective liver cancer control in Vietnam.

Hepatitis B and HIV co-infection in pregnant women: indication for routine antenatal hepatitis B virus screening in a high HIV prevalence setting.

Sub-Saharan Africa is endemic for hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections. HBV/HIV co-infection in women of reproductive age is of clinical and public health importance because these women constitute a significant reservoir for horizontal and perinatal HBV transmission. Childhood HBV vaccination from 6 weeks of age protects most children against chronic HBV infection. However, infants born to HBV/HIV co-infected women are more likely to be infected perinatally, with an increased risk of chronic hepatitis, than infants born to HBV mono-infected women. The aim of our study was to establish the prevalence of HBV infection and HBV/HIV co-infection in pregnant women in KwaZulu-Natal, South Africa, to inform antenatal HBV screening and childhood immunisation policies in South Africa. Stored plasma specimens obtained from 570 pregnant women were tested for hepatitis B surface antigen (HBsAg) and HBV infectivity, as characterised by the presence of hepatitis B e antigen (HBeAg) and/or HBV DNA load. The antenatal HIV prevalence and HBsAg prevalence in this study were 41.6% and 5.3% (95% confidence interval (CI) 3.4 - 7.1), respectively. Overall, 3.1% (95% CI 1.7 - 4.6) of pregnant women were HBV/HIV co-infected, with HBeAg positivity and the HBV DNA load being significantly higher in co-infected women. We report a 5.3% HBV prevalence and a 3.1% HBV/HIV co-infection prevalence in pregnant women from this HIV-endemic region. Routine antenatal HBV screening will allow early identification of neonates who require HBV active-passive immunoprophylaxis at birth. This strategy, together with antenatal antiretrovirals, will reduce the risk of perinatal HBV transmission, especially in high-risk HBV/ HIV co-infected pregnant women.

Causes of vertical transmission of hepatitis B virus under the at‐risk prevention strategy in Japan

The number of hepatitis B virus (HBV) carrier babies has decreased markedly since the introduction in Japan of an "at-risk" strategy for preventing HBV infection. However, elimination of HBV infection from our country appears difficult. To clarify the limitations of the at-risk strategy for preventing vertical transmission of HBV, causes of vertical transmission in a single hospital were retrospectively analyzed. The following causes were presumed in 17 carrier pediatric cases: five patients had prenatal HBV infection, HBV infection during/after the immunization program was confirmed in five cases, two patients had prenatal infection or infection during the immunization program and three cases were caused by human error (by the patients' guardians). Because their mothers were HBV-negative at screening and only developed acute hepatitis B in the perinatal period, another two cases (Cases 3 and 10) did not undergo immunization because they were not subjects of the at-risk strategy. Sequence analyses in ten patients revealed genotype C (subgenotype, C2/Ce) in nine cases and genotype A (subgenotype, A2/Ae) in one case (Case 3). In Japan, HBV subgenotype Ae has recently been found more frequently among sexually active men with acute hepatitis. There are concerns that horizontal transmission of HBV from these men to their pregnant partners could increase. These data suggest clear limitations to the at-risk strategy in Japan and the possibility that the increase in genotype A may influence vertical transmission of HBV.

Universal Hepatitis B Vaccination Reduces Childhood Hepatitis B Virus–Associated Membranous Nephropathy

To compare the incidence of hepatitis B virus (HBV)-associated membranous nephropathy (HBVMN) before and after universal HBV vaccination and to identify factors underlying the change. This study included 471 hospitalized children with nephrotic syndrome (NS) and 488 long-term follow-up hepatitis B surface antigen (HBsAg)-carrier children. Horizontal transmission (negative maternal HBsAg status) of HBVMN and HBV was assessed, and the incidence of HBVMN was compared before and after initiation of the universal HBV vaccination program started in 1984. The frequency of HBVMN in children with NS was 11.6% between 1974 and 1984, 4.5% between 1984 and 1994, 2.1% between 1994 and 2004, and 0% between 2004 and 2009. Similarly, the number of HBsAg-seropositive children with NS (mainly via horizontal infection) decreased after universal vaccination. The prevaccination frequency of HBV horizontal transmission in chronic HBsAg carriers from the general population was 36.5% compared with 5% in the postvaccination period. The incidence of HBVMN in these carriers revealed a parallel decline. Our results revealed a significant decrease in the frequency of HBVMN in children with NS and in long-term follow-up HBsAg carriers. Children with HBVMN are primarily infected with HBV via horizontal transmission; thus, the significant reduction in horizontal transmission in HBsAg-carrier children in the general population after universal HBV vaccination may explain the reduction of HBVMN in the vaccinated population. These findings confirm the effectiveness of HBV vaccination on reducing the incidence of HBVMN, possibly through a significant decline in horizontal HBV infection.

Knowledge on hepatitis B infection among pregnant women in a high endemicity area

ObjectiveTo assess the knowledge on hepatitis B virus (HBV) infection and associated factors among expectant mothers in an endemic region. MethodsA questionnaire was administered to pregnant Chinese women (n=1623) attending the antenatal clinic to examine their knowledge on HBV infection, and correlating this with socio-demographic, medical and obstetric factors. ResultsIndependent factors associated with insufficient reduced HBV knowledge include women outside the healthcare sector, lower education level, and no previous HBV testing. The majority of respondents could provide correct responses about the common aspects of HBV infection, including screening, blood-borne and perinatal transmissions, prevention by vaccination, and sequelae of HBV infection, but 47.1% did not know that HBV is transmissible by sexual intercourse. Over 75% respondents misunderstood the fact that HBV cannot be transmitted through food, or prevented by a balanced life style and nutrition. ConclusionsMisconceptions about HBV transmission are still common among the obstetric population, and the provision of appropriate and correct information is warranted to improve further the control of HBV infection to the target group. Practice implicationsAppropriate emphasis should be given to educating the general population about horizontal transmission of HBV.

HEPATITIS B VIRUS DNA IN SALIVA FROM CHILDREN WITH CHRONIC HEPATITIS B INFECTION

To explore the mechanism of horizontal transmission of hepatitis B virus (HBV) among children, we investigated the quantitative relationship between HBV in saliva and blood from 46 children with chronic hepatitis B. We found high levels of HBV DNA in saliva of HBeAg (+) children, suggesting saliva as a vehicle for horizontal transmission of HBV among children.

Prevalence and Phylogenetic Analysis of Hepatitis B Virus among Nonhuman Primates in Taiwan

Hepatitis B virus (HBV) is a public health problem worldwide, and apart from infecting humans, HBV has been found in nonhuman primates. This study investigated the prevalence and phylogenetic analysis of hepatitis B virus (HBV) and hepatitis D virus (HDV) among nonhuman primates in Taiwan, an area where human HBV remains endemic. Serum samples from 286 captive nonhuman primates (i.e., 32 great apes [Pan troglodytes and Pongo pygmaeus], 42 gibbons [Hylobates sp. and Nomascus sp.], and 212 Cercopithecidae monkeys) were collected and tested for the presence of HBV- and HDV-specific serologic markers. None of the Cercopithecidae monkeys were reactive against serologic markers of HBV. In contrast, 21.9% (7/32) of great apes and 40.5% (17/42) of gibbons tested positive for at least one serologic marker of HBV. Of these, five gibbons were chronic HBV carriers, characterized by presence of HBV DNA and hepatitis B surface antigen in the serum. HBV DNA was also detected in the saliva of three of the chronic carries. None of these HBV carrier gibbons exhibited symptoms or significant change in serum clinical chemistry related to HBV infection. Phylogenetic analysis of the complete HBV genome revealed that gibbon viruses clustered with other HBV isolates of great apes and gibbons from Southeast Asia and separately from human-specific HBV. None of the HBV-infected animals were reactive against HDV. These findings indicate that HBV found in these animals is indigenous to their respective hosts and might have been introduced into Taiwan via the direct import of infected animals from Southeast Asia. To reduce the horizontal and vertical transmission of HBV in captive animals, the HBV carriers should be kept apart from uninfected animals.

Chronic hepatitis B in Asian women of childbearing age

Hepatitis B virus (HBV) infection is a serious clinical problem affecting approximately 2 billion people worldwide. An estimated 350 million live with chronic hepatitis B (CHB) infection and are at an increased risk for serious liver sequelae and death from acute or chronic consequences of CHB infection. Individuals with CHB have a 20-30% risk of early death from complications, including liver cirrhosis and hepatocellular carcinoma. In the Asia-Pacific region, half of the CHB burden results from vertical or mother-to-child transmission, with early childhood horizontal transmission accounting for the remaining half. Screening and vaccination are key factors in the successful prevention and control of HBV infection. Over the last 20 years, the implementation of screening programs and universal HBV vaccination for all individuals born in endemic areas have reduced the prevalence of HBV infection and HBV-related liver diseases among individuals younger than 30 years. Women of childbearing age are key stakeholders in preventing HBV infection and, as such, play a critical role in reducing the vertical and horizontal transmission of HBV. Further efforts are needed to implement screening and educational programs for women of childbearing age, particularly those with CHB, to prevent the transmission of HBV to newborns, spouses, other household members, and sexual partners. In addition, healthcare workers need to learn how to avoid iatrogenic transmission in the healthcare setting. This article reviews these issues and highlights areas in which their engagement with public health efforts serves to improve quality of life and society as a whole.

Prevalence of Hepatitis B Infection among Schoolchildren in Southeast Turkey

Aim: Hepatitis B virus (HBV) infection is a worldwide health problem. The objectives of this study were to determine the impact of the Expanded Programme on Immunization (EPI) on the prevalence of HBsAg carrier rate and immunity developed against HBV infection among schoolchildren in southeast Turkey. Materials and Methods: The study population consisted of 147,200 healthy schoolchildren between 6 to 17 years of age living in the Mardin area. A total of 802 children were randomly selected by systematic sampling method. Hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc) were analyzed in blood samples by enzyme-linked immunosorbent assay (ELISA General Biological Corp., Taiwan). Results: This study involved 420 (52.4%) male and 382 female (47.6%) schoolchildren with a mean age of 10.4 ± 2.3 years. The overall anti-HBs, anti-HBc, and HBsAg were positive in 724 (90.2%), 56 (7%), and 22 (2.7%) children, respectively. The overall HBV seroprevalence rate was 2.7% . Conclusions: The introduction of the national EPI has successfully decreased the HBV seropositivity possibly by preventing perinatal and horizontal HBV transmission among schoolchildren in southeast Turkey.

Chronic Diarrhea as First Manifestation of Liver Cirrhosis and Hepatocarcinoma in a Teenager

Hepatocellular carcinoma (HCC) is rare in children, accounting for approximately 0.5% of all pediatric malignances (1). It is the second most common hepatic malignancy in children after hepatoblastoma, with an incidence of 0.5% to 1.0% cases per million (2). HCC is closely associated with chronic hepatitis B virus (HBV) infection and occurs mainly in adults between 40 and 60 years of age (3Y5). However, HCC may develop in children who live in hyperendemic areas as a consequence of vertical or horizontal HBV transmission (6). With the introduction of HBV vaccination programs, the incidence of HCC has declined markedly in many countries (3,5,7). In Brazil, the vaccination program began in 1990. Thus, there is still a sizable number of people with chronic HBV infection. The symptoms of HCC are usually those of chronic liver disease and are generally nonspecific (8). Chronic diarrhea has been described as one manifestation of liver cirrhosis and HCC. Its pathogenesis is poorly understood and probably multifactorial. This report describes a patient with cirrhosis and HCC who presented with chronic diarrhea. Possible mechanisms leading to diarrhea are discussed.

Differential seroprevalences of hepatitis C virus, hepatitis B virus and human immunodeficiency virus among intravenous drug users, commercial sex workers and patients with sexually transmitted diseases in Chiang Mai, Thailand

To elucidate the differences in the mode of transmission of three blood-borne viruses, hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus (HIV), under comparable conditions of study, we analyzed the prevalences of anti-HCV antibodies (anti-HCV), anti-HBV core antibodies (anti-HBc), HBV surface antigen (HBsAg) and anti-HIV antibodies (anti-HIV) in different risk populations in Chiang Mai, Thailand, where the prevalence of HIV infection is high. The subjects consisted of 98 intravenous drug users (IVDU), 100 commercial sex workers (CSW) and 50 male patients with sexually transmitted diseases (STD). In IVDU the prevalence of anti-HCV was the highest (85%), followed by anti-HBc (77%) and anti-HIV (46%), whereas in CSW and STD the prevalence of anti-HCV was 2 and 0%, respectively, that of anti-HBc 69 and 64%, respectively, and that of anti-HIV 11 and 14%, respectively. The prevalence of anti-HBc minus that of HBsAg, representing horizontal transmission of HBV, was similar for IVDU (63%), CSW (58%) and STD (64%). Thus, HCV is mainly transmitted by blood contact, HIV primarily by blood contact rather than by sexual contact, and HBV equally readily by blood or sexual contact. These findings were supported by the results of logistic regression analysis.

Decline of hepatitis B carrier rate in vaccinated and unvaccinated subjects: sixteen years after newborn vaccination program in Taiwan.

Taiwan was an endemic area for hepatitis B virus (HBV) infection, and related liver diseases cause a significant drain of public resources. To control the endemic, a nation-wide newborn vaccination program was started in 1985. We reviewed the results of the annual survey for HBV surface antigen (HBsAg) performed in freshmen class of two high schools in Hualien, eastern Taiwan, from 1991 to 2001. A total of 10,194 students, most of them 15 years old, were tested for serum HBsAg using enzyme immunoassays. There is a significant trend (P < 0.0001) of decreasing HBsAg carrier rate from 20.3 to 4.4% in males and 14.3% to 2.4% in females, respectively, over 11 years. The HBsAg carrier rate was 16.0-20.3% in students surveyed during 1991-1993 (born more than 6 years before the start of the national vaccination program), which decreased to 7.7-11.9% during 1994-1999 (born 1-6 years before the program). It further declined to 4.7% and 3.4% in 2000 and 2001 (born after the start of the program). The HBsAg carrier rate in male students was significantly higher than that in female students in most of the years. The HBV newborn vaccination program not only successfully prevented most of the perinatal transmission of HBV but also reduced horizontal transmission of HBV to children born up to 6 years before the start of the program. Also, the protection persisted for at least 15 years.

Trend of hepatitis B virus infection in freshmen classes at two high schools in Hualien, Taiwan from 1991 to 1999.

Taiwan is an endemic area of hepatitis B virus (HBV) infection. A nationwide mass vaccination program to prevent HBV infection was started in 1985. Perinatal and horizontal transmission of HBV decreased substantially after the launching of this program. However, the influence of this program on children born before 1985 has not been studied. From 1991 to 1999, annual surveys of hepatitis B virus surface antigen (HBsAg) and antibody (anti-HBs) were carried out in freshmen at two high schools in Hualien, Taiwan. The average age was 16 years old. Although these students were born 2-10 years after the start of the national HBV vaccination program, there is a significant trend of decreasing HBsAg carrier rate (from 21.0% to 10.5% in males and 14.3% to 4.7% in females) and increasing anti-HBs rate (from 56.6% to 67.8% in males and 70.3% to 75.9% in females) over the 9 years. With yearly comparison, the carrier rate of HBsAg started to show significant decrease since 1994, while the anti-HBs began to rise significantly after 1996, especially in male students. The HBsAg carrier rate in male students was significantly higher, while the anti-HBs rate was significantly lower, than that in female students in most of the years. It is concluded that the effect of HBV vaccination also reduced horizontal transmission of HBV to children born up to 7 years before the start of the program.