Hepatitis B antigen, antigen subtypes, and hepatitis B antibody in normal subjects and patients with liver disease: Results of a collaborative study*

The relative sensitivities of counterimmunoelectrophoresis (CIE) and haemagglutination assays for the detection of hepatitis B surface antigen (HB_sAg) and antibodies (anti-HB_s) were compared. Twelve scientists from ten countries in Asia, Africa and the Pacific region participated in the study. The participants provided serum samples from 15 953 subjects comprising patients with acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC), as well as blood donors and other normal individuals. For the detection of HB_sAg in a reference panel serum, immune adherence haemagglutination (IAHA) was slightly more sensitive than passive haemagglutination inhibition (PHI); CIE was the least sensitive. Mean HB_sAg frequencies in patients with acute hepatitis, chronic hepatitis, cirrhosis, and HCC were significantly higher than in healthy controls. Passive haemagglutination (PHA) was more sensitive than CIE for the detection of anti-HB_s. The frequency of anti-HB_s in patients with HCC was significantly lower than that in the other groups. Mean anti-HB_s frequencies in patients with acute hepatitis, chronic hepatitis, and cirrhosis were not significantly different from that in normal subjects. Subtyping of HB_sAg was performed by PHI. Among asymptomatic carriers the predominant HB_sAg subtype in northeast Asia was adr.In India, ayw predominated in carriers, with the demarcation between adr and ayw occurring west of Burma. In West Africa the only subtype detected was ayw, but in East Africa the majority subtype was adw. The r subtype was found only in Asian populations east of India and in Western Pacific populations. In Papua New Guinea all four subtypes were identified. With one possible exception, the subtypes of HB_sAg-positive patients with liver disease reflected the predominant type in each geographic location.     

北京地区HBsAg亚型分布特征

本文报告的300名HBsAg (+)者分布于262户家庭内,其中有14户家庭分别有2名以上的HBsAg (+)者。在该14户家庭内,有7户家庭的HBsAg (+)者属于同亚型,其它7户家庭的HBsAg (+)者属于异亚型。一些家庭内的HBsAg (+)者呈现同一种亚型,可能是由于通过家庭来源感染HBV的结果,但也不能排除通过社会来源感染HBV的可能性。另一些家庭HBsAg呈现两种亚型,则可以肯定是通过社会来源而感染HBV。     

Prevalence of specific markers of viral hepatitis A and B among an Ethiopian population

There have been few reports from Africa, and none from Ethiopia, pertaining to seroepidemiological investigation of viral hepatitis A and B. In this study, 396 serum samples, from male and female Ethiopian subjects aged between 3 and 60 years, were tested for specific markers of hepatitis A and B. Antibodies to hepatitis A virus were detected in 99% of the study population. There was an overall prevalence of hepatitis B surface antigen (HBsAg) of 9%, with a peak value of 15% in the age groups 21-30 years and ≥41 years. The pattern of age prevalence of HBsAg was similar to that found in China (province of Taiwan), Senegal and Thailand. The distribution of the subtypes of HBsAg was in line with that generally found in east Africa, northern Europe, and central America, where subtype ad predominates. HBsAg was found in 3 times more men than women (10.5% and 3.5%, respectively). Antibodies to hepatitis B surface antigen were found in 67% of the population, and were evenly distributed between males and females. In general, the results indicated that hepatitis B virus is more endemic in rural, rather than urban, areas, while hepatitis A virus is endemic throughout the country.     

A seroepidemiological study of the prevalence of hepatitis B infections in a hyperendemic New Zealand community

The prevalence of hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs) were studied in 93% of the population of the New Zealand township of Kawerau. Sera were collected from 7901 subjects over six months old, and 3318 (42%) had markers of hepatitis B virus (HBV) infections. Five hundred and nineteen (6.6%) were positive for HBsAg and 485 (96.4%) of 503 retested were confirmed as chronic carriers. HBsAg prevalence was 5.4% in the 0-4 years age group but only 1 of 66 children under one year old was positive suggesting that later cross infection, rather than perinatal transmission was the major factor responsible for the high pre-school carrier rate. Total HBV marker prevalence increased dramatically in early school years and peak marker prevalence was 67.7% in the 15-19 year age group. Prevalence of HBsAg was more than four times higher in non-europeans than in Europeans (Caucasians). Other factors significantly associated with hepatitis B virus marker prevalence in children were: number of years spent in Kawerau, which was associated with anti-HBs prevalence; and size of household, which was associated with HBsAg prevalence. Number of siblings was not a significant risk factor over and above the effect of size of household. Factors associated with marker prevalence in adults were: number of years spent in Kawerau, which was associated with anti-HBs; birth in the Northern half of the North Island, which was associated with both HBsAg and anti-HBs; size of household, which was more strongly associated with HBsAg prevalence; and amateur tattoos, which were associated with anti-HBs prevalence but not with HBsAg prevalence.     

汉藏傣瑶维蒙黎族人群乙型肝炎病毒感染调查

对可代表我国主要语系的七个民族的人进行ＨＢＶ感染的血清流行病学调查。经人口数据标准化后，ＨＢｓＡｇ检率汉１５．３％；而藏２６．２％，瑶２４．０％，显著较高；黎７．０％、维５．３％，显著较低。ＨＢｓＡｇ检出率汉１５．３％；显著较低。ＨＢｓＡｇ检出的人群年龄高峰、科学交早降落；在其育龄妇女未检出ＨＢｅＡｇ，或可部分解释其人群较低感染的原因。抗ＨＢｓ／ＨＢｓＡｇ比率一般在１．６１－２．０６；而藏仅０．８     

Universal immunization of infants with low doses of a low-cost,plasma-derived hepatitis B vaccine in South Africa

OBJECTIVE: To evaluate the effectiveness of universal vaccination against viral hepatitis B in South Africa among 18-month-old rural children. METHODS: Children were immunized with a course of low-dose (1.5 microg), plasma-derived hepatitis B vaccine at 6, 10 and 14 weeks of age, and blood samples from the children were tested for three hepatitis B markers: hepatitis B surface antigen (HBsAg), anti-HBs and anti-HBc. FINDINGS: One year after vaccination, a protective anti-HBs antibody titre of at least 10 IU/l was present in 669/769 (87.0%) of blood serum samples tested. Only 3/756 children (0.4%) were HBsAg positive and a fourth child was anti-HBc positive (HBsAg negative). This is a marked decrease compared to the hepatitis B prevalences reported in previous studies. Among rural migrant mine-workers, for example, HBsAg prevalence was 9.9%, and was 10.1% among children 0-6 years of age in the Eastern Cape Province. CONCLUSION: The low-dose, plasma-derived hepatitis B vaccine, which is affordable to most developing countries, was very successful in controlling endemic hepatitis B infection, where the virus is predominantly spread by horizontal transmission among infants and young children.     

Epidemiological serosurvey of Hepatitis B in China—Declining HBV prevalence due to Hepatitis B vaccination

Objective

To determine the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core anti-body (anti-HBc) in a representative population in China 14 years after introduction of hepatitis B vaccination of infants.

Methods

National serosurvey, with participants selected by multi-stage random sampling. Demographics and hepatitis B vaccination history collected by questionnaire and review of vaccination records, and serum tested for HBsAg, antibody to anti-HBc and anti-HBs by ELISA.

Findings

The weighted prevalences of HBsAg, anti-HBs and anti-HBc for Chinese population aged 1–59 years were 7.2%, 50.1%, 34.1%, respectively. HBsAg prevalence was greatly diminished among those age <15 years compared to that found in the 1992 national serosurvey, and among children age <5 years was only 1.0% (90% reduction). Reduced HBsAg prevalence was strongly associated with vaccination among all age groups. HBsAg risk in adults was associated with male sex, Western region, and certain ethnic groups and occupations while risk in children included birth at home or smaller hospitals, older age, and certain ethnic groups (Zhuang and other).

Conclusions

China has already reached the national goal of reducing HBsAg prevalence to less than 1% among children under 5 years and has prevented an estimated 16–20 million HBV carriers through hepatitis B vaccination of infants. Immunization program should be further strengthened to reach those remaining at highest risk.     

Hepatitis B virus infection in children. A sero-epidemiological study in three endemic areas

The occurrence of hepatitis B surface antigen (HBsAg) and anti-HBs was studied in 254 children aged 0 to 19 years from three areas in Greenland and West Africa, endemic for hepatitis B virus (HBV) infection. Age specific prevalence rates for HBsAg increased in all areas until the age of 10 years while the prevalence of anti-HBs showed a continuous rise and reached maximum level of 44 to 80% in the age group 15 to 19 years. The study results indicate that in these areas infection with HBV occurs throughout childhood, and that HBsAg carriership is derived mainly from infection in the first decade of life, but not only neonatal infection, Such data are necessary for all areas in which attempts to control HBV infection are being made.     

e系统在HBsAg阳性各种肝病病人中的检出情况及其流行病学意义

本文采用琼脂扩散法检查了644份血清的HBeAg和抗-HBe系统。其中226份血清系取自病毒性肝炎或慢性肝病病人,295份为无症状的HBsAg携带者,83份为HBsAg阴性而抗-HBs阳性,58份为HBsAg和抗-HBs均为阴性病人的血清。结果表明各种肝病病人的HBeAg和抗-HBe阳性率分别为22.57%和3.98%,无症状携带者的HBeAg和抗-HBe阳性率分别为21.36%和8.47%,与病人检出率无明显差别。在HBsAg(一)但抗-HBS (+)血清中不但能检出抗-HBe,同时也检出HBeAg,阳性率分别为15.79%和13.16%。在HBsAg和抗-HBs均(一)的血清中不能检出e系统。血清中GPT值的高低与e系统的检出率无关。HBeAg在男、女两性中检出无差异(20.45%和22.99%),但抗-HBs女性高于男性(ll.22%和4.55% P<0.01)。在青少年中HBeAg检出率明显高于大年龄组。家庭中有HBeAg阳性者,其家庭成员中HBsAg阳性率明显高于HBeAg阴性家庭,但抗-HBe的存在却无何影响。     

2005～2006年福州市自然人群乙型肝炎病毒感染状况调查

[目的]了解福州市乙型肝炎病毒(HBV)感染现况,为制订乙肝预防控制策略提供科学依据。[方法]2005年11月至2006年3月,在福州市抽取部分自然人群进行HBV感染状况调查。[结果]调查1538人,HBV感染率为59.56%,其中HBsAg阳性率为13.33%,抗-HBs阳性率为53.25%,HBeAg阳性率为2.28%,抗-HBe阳性率为17.04%,抗-HBc阳性率为56.83%。全部调查对象中,抗-HBs、抗-HBc双阳性者最多,占25.75%。沿海地区HBsAg、HBeAg阳性率均高于平原地区与山区(P<0.05);HBsAg、抗-HBe阳性率15~49岁较高(P<0.01);HBsAg阳性率呈现明显的家庭聚集现象。乙肝疫苗免疫人群HBsAg、抗-HBe、抗-HBc阳性率均低于未免疫人群(P<0.01)。[结论]当前福州市居民HBsAg阳性率高于全国平均水平,应在沿海及HBV感染者家庭成员中加强乙肝预防,做好乙肝疫苗接种工作。     

Post-vaccination serologic testing of infants born to hepatitis B surface antigen positive mothers in 4 provinces of China

ObjectiveTo evaluate prenatal maternal hepatitis B virus (HBV) screening and post-vaccination hepatitis B surface antigen (HBsAg) and antibody to hepatitis B surface antigen (anti-HBs) status and titers of babies born to HBsAg positive mothers, and to provide evidence for development of standard postvaccination serologic testing (PVST) strategies for babies born to HBsAg positive mothers in China.MethodsIn 2014, we conducted a baseline survey of HBV mother to child transmission (MTCT) interruption strategy implementation and PVST for babies born to HBsAg positive mothers after received 3 doses of hepatitis B vaccine (HepB) in 8 counties in 4 Provinces. Bivariate analysis and multivariable analyses modeled statistically significant predictor variables associated with infant HBsAg, anti-HBs positive, anti-HBs titer.ResultsAmong the 1563 infants born to HBsAg positive mothers, 1025 (65.6%) maternal-infant pairs were enrolled in PVST after receiving 3 doses of HepB. 38 infants tested HBsAg positive for an HBsAg positive rate of 3.7%. Maternal hepatitis B e antigen (HBeAg) status and age of infant were significantly associated with infant HBsAg positivity. A total of 932 infants were anti-HBs positive when tested at 7–24 months of age, yielding an anti-HBs positivity rate of 90.9%. Maternal HBeAg status was the factor associated with infant anti-HBs status. Amount of antigen of HepB and infant’s age were most associated with anti-HBs titers. PVST performed 1–2 months after the 3rd dose of HepB was associated with the highest anti-HBs level and the anti-HBs Geometric Mean Concentration (GMC) decreased as the PVST intervals prolonged.ConclusionsIn China, perinatal HBV transmission is approaching the theoretical minimum possible with the current strategy of HepB coupled with HBIG administration for HBV-exposed newborns. PVST of infants born to an HBsAg positive mother is an essential strategy to ensure full protection for vaccine non-responders and appropriate medical care for those infected.     

安徽省某市农村地区人群乙型肝炎流行现况及相关知识调查

目的了解安徽省某市农村地区人群乙型肝炎（简称乙肝）的流行状况及相关知识掌握情况。方法采用分层整群抽样的方法,对合肥市农村地区居民2038人进行问卷调查,并采集静脉血3ml,用ELISA方法进行HBsAg及抗-HBs检测。结果在2038份血清标本中,HBsAg标化流行率为6.44%,抗-HBs标化流行率为46.85%,HBsAg流行率在性别之间差异无统计学意义（χ2=0.559,P〉0.05）,农民HBsAg流行率最高,达9.06%,学生群体HBsAg流行率最低,为2.70%。1992年及之后出生的群体HBsAg流行率显著低于1992年之前出生的群体（χ2=8.120,P〈0.05）。乙肝疫苗的标化接种率为38.87%,学生乙肝疫苗接种率最高,为85.41%,农民乙肝疫苗接种率最低,仅12.19%。乙肝知识得分调查农民群体最低;乙肝知识的三大获取途径依次是电视、广播以及报刊书籍。结论调查地区人群中HBsAg流行率为6.44%,低于全国平均水平,但抗-HBs水平偏低,农村居民对乙肝相关知识的了解程度偏低,应加强农村地区乙肝知识的健康教育,提高乙肝疫苗接种率。     

The long-term efficacy of Chinese hamster ovary cell derived hepatitis B vaccine after being used for 14–16 years in Chinese rural communities

ObjectiveTo evaluate the long-term efficacy of Chinese hamster ovary (CHO) cell derived hepatitis B vaccine after being used for 14–16 years in country community in Hebei province in China.MethodA cross-sectional investigation was carried out in 3 of 7 randomly selected rural communities in Zhengding County in 2013. The children who were born between 1997 and 1999 and were vaccinated with three doses of CHO-derived hepatitis B vaccine were eligible to participate in the study. Their sera samples were tested for HBV serological markers. For HBsAg positive children, their historical results were compared, in order to see whether these were new infections.ResultsAmong the 920 participating children, the prevalence of HBsAg, anti-HBs and anti-HBc were 0.65%, 73.15% and 1.20% respectively. The differences between birth-year groups were not significant. When compared with baseline, the vaccine efficacy was 94.2% and the anti-HBs titers of 668 children with sole anti-HBs positivity were 178.8 mIU/ml. By comparing with historical data, no new infection was found in this latest survey. Among 6 mothers of HBsAg positive children, 4 were HBsAg positive, 1 was negative and 1 was unknown.ConclusionThe long-term efficacy of the CHO derived hepatitis vaccine is good and stable for 14–16 years after vaccination. A booster dose seems not necessary. Implementing mother–newborn blocking measures for newborns from HBsAg carrier mothers is urgently needed in the future.     

辽宁省乙型肝炎血清流行病学分析

目的 了解辽宁省1~29岁人群乙型肝炎(乙肝)感染现状,评价乙肝疫苗免疫策略的效果。方法 采用分层二阶段整群随机抽样方法抽取辽宁省6个县区1756人为研究对象采集血清,用ELISA进行乙肝3项指标检测。结果 辽宁省1~29岁人群HBsAg阳性率为0.68%,标化阳性率为1.58%;Anti-HBs阳性1035例,阳性率58.94%,标化阳性率为53.41%;Anti-HBc阳性者88例,阳性率为5.01%,标化阳性率为9.60%;男女性3项指标阳性率比较差异均无统计学意义;各年龄组调查人群比较,HBsAg阳性率最高为20~24岁组(3.60%),Anti-HBs阳性率最高为1~4岁组(71.51%),Anti-HBc阳性率最高为25~29岁组(18.64%),HBsAg和Anti-HBc阳性率呈现总体趋势随着年龄增大而升高;是否有疫苗免疫史的人群HBsAg、Anti-HBs和Anti-HBc阳性率比较差异均有统计学意义。结论 辽宁省HBsAg阳性率下降,疫苗接种效果明显。     

2010-2012年杭州市西湖区学龄前儿童病毒性乙型肝炎血清标志物分布和流行规律

目的 分析杭州市西湖区学龄前儿童病毒性乙型肝炎血清标志物的分布和流行规律. 方法 选取杭州市西湖区2010-2012年间0～6岁的学龄前儿童2 578例,利用ELISA法检测儿童体血清内HBsAg、anti-HBs、HBeAg、anti-HBe、anti-HBc水平. 结果 HBsAg及anti-HBs的阳性检出率分别为1.12％和57.76％,男性学龄前儿童的HBsAg 的阳性检出率要显著高于女性学龄前儿童,而女性学龄前儿童的anti-HBs的阳性检出率要显著高于男性儿童.2010、2011、2012连续三年的动态监测发现anti-HBs的阳性检出率呈现出逐年上升的趋势,而HBsAg的阳性检出率则呈现出逐年降低的趋势. 结论 定期的对学龄前儿童进行乙型肝炎血清标志物的检测,并及时的对其中的易感人群进行疫苗的补种,这样才能有效的防止乙肝的感染.     

Epidemiological distribution of hepatitis B virus genotypes in 1–29-year-olds in the mainland of China

BackgroundTo analyze the epidemiological distribution of Hepatitis B virus (HBV) genotype in the mainland of China following the implementation of effective preventive measures.MethodsFive hundred and seventeen HBsAg-positive subjects aged 1–29 years surveyed in the 2014 national HBV sero-survey in the mainland of China were enrolled in the study. The full-length HBV genome was obtained by PCR amplification and sequencing. The HBV genotype was determined by phylogenetic analysis. Combined with questionnaire information, HBV genotype distribution was analyzed.ResultsOf the 517 HBsAg-positive subjects, 369 (71.4%) were included in the analysis. HBV genotypes found were B (45.0%), C (36.6%), D (6.0%), C/D (9.8%), B/C (2.2%), and I (0.5%). Geographic differences in HBV genotype were significant for seven regions. Three serotypes were found: adw (47.2%), adr (35.5%), and ayw (17.3%). B2 (43.9%) and C2 (25.2%) were the two major subgenotypes. The predominant genotypes differed between the Han group and the other ethnic groups. No statistical differences in genotype distribution were found by gender, age group, or hepatitis B (HepB) vaccination history.ConclusionThe prevalence of HBV genotype B was higher than that of genotype C with subgenotypes B2 and C2 endemic in 1–29-year-olds in the mainland of China, after HBV prevalence has reduced significantly due to the implementation of preventive measures. HepB vaccination or other factors did not interfere with HBV genotype distribution. The surveillance of HBV genotype was essential for responding to the potential changes and impact on the preventive policies in the future.     

Prevalence study of different hepatitis markers among pregnant Albanian refugees in Greece

Aim of the study was to record the prevalence of the various types of viral hepatitis, especially hepatitis B, in pregnant Albanian refugees in Greece. The study comprised 500 pregnant refugees of mean age 25:1 ± 4,6 years. In Albania, all women had lived in overcrowded houses and had been exposed to non throw-away needles and syringes. Various indices for all hepatitis types were determined. The prevalence of HBsAg was 13.4%, of anti-HBs 53%, of total anti-HBc 70.8%, of anti-HBc IgM 0.4%, of HBeAg 1.2%, of anti-HBe 58.6%, of anti-HAV 96.2%, of anti-HAV IgM 1%, of anti-HDV 0.4%, of anti-HCV 0.6% and of anti-HEV 2%. HBeAg was found positive in 7.5% of HBsAg carriers. Prevalence of hepatitis B markers, as determined by HBsAg and/or anti-HBs and/or total anti-HBc was significantly higher in those with a history of previous hospitalization in Albania (p = 0.01) and those with previous history of hepatitis (p = 0.02). The high prevalence of hepatitis B markers in pregnant Albanian refugees proves that HBV infection is highly endemic in Albania and the possibility of perinatal transmission to the offsprings urges for HBV vaccination programmes. On the other hand improvements in the socioeconomic conditions and the sanitation system in Albania is anticipated to reduce the incidence of HAV and HBV infections.     

Impact of pooling on accuracy of hepatitis B virus surface antigen screening of blood donations

Expenditure on screening blood donations in developing countries can be reduced by testing donations in pools. This study evaluated serological screening in pools for hepatitis B virus (HBV) at the Israeli national blood bank and a hospital blood bank in Gaza, the Palestinian Authority. The accuracy of HBV surface antigen (HBsAg) enzyme immunoassay performed on pools of 3-24 samples was compared with individual tests. Delay in detecting positive samples due to dilution in pools and the possibility of antibody-antigen neutralization were analyzed. The sensitivity of pooled testing for HBsAg was 93-99%, prolonging the window period by 5 days (8.3%). Neutralization of HBsAg by hepatitis B surface antibodies (anti-HBs) could be minimized by testing immediately after pooling. Serological testing for HBsAg in pools may be performed using manually created pools of up to six samples, with 5% loss in sensitivity and a risk of neutralization by anti-HBs present in the donor population. Pooling can therefore be considered as an option only in countries with a low prevalence of HBV.     

深圳市流动人口与户籍居民乙肝感染情况比较分析

  目的  了解深圳市罗湖区乙型肝炎（以下简称乙肝）综合防治示范区内 ≥ 18岁劳务工人乙肝病毒感染状况,为深圳市劳务工人乙肝病毒的防治提供科学依据。  方法  选取罗湖辖区范围内于2019年4月 — 2020年6月间进行健康体检的劳务工人,在取得知情同意后完成问卷调查并采集肘静脉血液,采用酶联免疫吸附实验检测血清乙肝表面抗原和抗体。  结果  共收集到5 493名劳务工人血液标本及调查问卷,乙肝表面抗原（HBsAg）阳性率为6.54 %,乙肝表面抗体（抗 – HBs）阳性率为60.37 %,不同年龄、文化程度、职业、户籍来源以及乙肝疫苗接种史比较,HBsAg和抗 – HBs阳性率差异均有统计学意义,将2项乙肝血清标志物中单因素分析有意义的变量采用二元logistic回归分析,结果发现接种乙肝疫苗是HBsAg感染的保护性因素,文化程度初中及中以下、年龄30～49岁是危险性因素;而接种疫苗、< 30岁人群和户籍为华东地区抗 – HBs阳性率高于其他人群。  结论  深圳市罗湖乙肝综合防治示范区乙肝病毒感染率较国家“十一五”期间有所降低,但还应加强重视 < 20岁年龄组、户籍来源为西南、东北和西北以及未接受过乙肝疫苗接种人群的乙肝防治工作。     

Seroepidemiology of hepatitis B virus infection among adults in Singapore: A 12-year review

We undertook a national hepatitis B seroprevalence study to assess the seroprevalence of hepatitis B virus (HBV) markers in the adult population in Singapore in 2010 and make comparisons with the seroprevalence in 1998 and 2004. The study involved residual sera from national health surveys conducted every six years since 1998. The tests for HBV markers were carried out using commercial chemiluminescent microparticle immunoassay. In 2010, the prevalence of hepatitis B surface antigen (HBsAg) among 3293 Singapore residents aged 18–79 years was 3.6% (95% confidence interval [CI] 2.9–4.2%). Hepatitis B e antigen (HBeAg) was detected in 4.2% of those who were HBsAg positive. About 22.5% (95% CI 21.1–23.9%) were positive for antibody to hepatitis B core antigen (anti-HBc). The overall population immunity to HBV, as determined by antibody to hepatitis B surface antigen (anti-HBs) ≥ 10 mIU/mL, was 43.9% (95% CI 42.2–45.6%). Among young adults below 30 years of age, HBsAg prevalence (1.1%) was half that in 1998 and 2004, and in those positive for HBsAg, none was positive for HBeAg in 2010, compared to 20.8% in 1998 and 15.8% in 2004. In this age group, anti-HBc prevalence also decreased significantly from 22.1% in 2004 to 4.4% in 2010, while anti-HBs (≥10 mIU/mL) prevalence increased significantly from 27.9% in 1998 to 43.3% in 2010 (p < 0.001). The national childhood HBV immunisation and catch-up programmes implemented in 1987 and 2001–2004, respectively, had a significant impact in reducing HBV infection and in raising the immunity of the adult population 18–29 years of age.