Presence of immune memory and immunity to hepatitis B virus in adults after neonatal hepatitis B vaccination

Neonatal vaccination against hepatitis B virus (HBV) infection was launched in the 1980s in Qidong, China, where HBV and hepatocellular carcinoma were highly prevalent. Presence of immune memory and immunity against HBV in adults needs to be clarified. From a cohort of 806 who received plasma-derived Hep-B-Vax as neonates and were consecutively followed at ages 5, 10, and 20 years, 402 twenty-four-year-old adults were recruited for booster test. Among them 4 (1%) were found to be HBsAg(+), 27 (6.7%) were HBsAg(−)anti-HBc(+), 121 (30.2%) were HBsAg(−)anti-HBc(−)anti-HBs(+), and 252 (62.4%) were HBsAg(−)anti-HBc(−)anti-HBs(−). Of them, 141 subjects with HBsAg(−)anti-HBc(−) were boosted with 10-μg recombinant HBV vaccine on day-0 and 1-month. The conversion rates of anti-HBs ≥10 mIU/ml on D10-12 and 1-month post-booster were 71.4% and 87.3% respectively in the vaccinees who were anti-HBs(+) at age 5, higher than in those who were anti-HBs(−) at age 5, 57.5% and 80.0% respectively, but no statistically significant. After the second dose of booster, all subjects with anti-HBs(+) at age 5 had anti-HBs >500 mIU/ml. However, 6/40 subjects, with anti-HBs(−) at age 5, had anti-HBs <10 mIU/ml, geometric mean concentration was 3.6 (95% CI 2.0-7.7). Of the subjects received booster, 44 subjects were determined the presence of T cell immunity on D10-12, 41 had HBsAg-specific T cells detectable, including 7/10 subjects whose anti-HBs were <10 mIU/ml 10-12 days post-booster. Among 27 HBsAg(−)anti-HBc(+) subjects, 19 had detectable serum HBV-DNA, and an “a” epitope mutation was found in 1/5 HBV isolates. One subject who was anti-HBc(+) at age 20 converted into HBsAg(+) 4 years later. The adults received neonatal HBV vaccination had immune memory and immunity against HBV infection. However, 31.9% of neonatal HBV vaccinees who responded weakly at an early age might be susceptible to HBV infection after childhood.     

Stable seroepidemiology of hepatitis B after universal immunization in Taiwan: A 3-year study of national surveillance of primary school students

Background

This study is aimed to investigate if there was increased risk of HBV acquisition among first graders in Taiwan during a 3-year follow-up period.

Methods

A total of 1545 healthy first graders, who were vaccinated against HBV in infancy, were recruited in 2005. All subjects were checked for hepatitis B surface antigens (HBsAg), antibodies to HBsAg (anti-HBs), and to the hepatitis B core antigen (anti-HBc). Nucleotide sequence of the “a” determinant of HBsAg was determined by polymerase chain reaction and direct sequencing in the HBsAg carriers.

Results

Among 1545 subjects, 0.78% were HBsAg seropositive, 54.30% were anti-HBs seropositive, and 1.68% anti-HBc seropositive. Three of the 10 HBV carriers (30%), whose HBV DNA were sequenced for the S gene, had surface antigen mutants at the “a” determinant.

Conclusion

There were no new chronic HBV infections in this cohort of children for two consecutive years. HBV S gene vaccine escape mutants did exist in the vaccine-failure population, but they may not have made a major health impact.     

The first five years of universal hepatitis B vaccination in South Africa: evidence for elimination of HBsAg carriage in under 5-year-olds.

South Africa implemented a vaccine against hepatitis B virus (HBV) into the Expanded Programme on Immunisation (EPI) in April 1995. The HBV vaccine is given at 6, 10, and 14 weeks, in parallel with OPV, DTP and Hib vaccines. This study assessed the impact of universal childhood HBV vaccination programme in reducing HBsAg carriage, in the first five years (1995--1999) since its implementation. In parallel, we investigated the current burden of HBV infection in mothers of vaccinees and the adult general population. A total of 598 babies (mean age=23.3 months) who received 3 doses of 1.5 microg/0.5 ml Hepaccine-B (Cheil) were recruited from the Northern Province (one of the nine provinces in South Africa). HBsAg, anti-HBs, anti-HBc, HBeAg and anti-HBe were tested using the IMx or Axsym kits (Abbott Laboratories). PCR assays were performed following established protocols. The overall seroprotection rate (i.e. anti-HBs titre> or =10 mIU/ml) was 86.8% (519/598) in vaccinated babies, while 13.2% had anti-HBs levels<10 mIU/ml. Seroprotection rates and geometric mean titres (GMT) decreased significantly with increasing age, possibly reflecting waning anti-HBs titre over time. Total HBV exposure (positive for either HBsAg, anti-HBs, or anti-HBc) was 31.0% (58/187) in mothers of vaccinees and 40% (72/180) in the adult general population. HBsAg carrier rate was virtually similar in both groups (3.2% in mothers of vaccinees vs. 3.3% in the general population). Against this background, no vaccine failures resulting in HBsAg and HBV DNA positivity were seen in vaccinated babies, including 6 babies born to HBsAg positive carrier mothers (one carrier mother was positive for HBeAg and HBV DNA). However, 0.9% (5/582) babies, aged between 8--11 months, tested positive for anti-HBc, all of whom had anti-HBs titres>10 mIU/ml and were negative for HBV DNA. Anti-HBc positivity was probably maternal in origin, or may represent sub-clinical averted HBV infections. It can be concluded that the HBV vaccine is highly effective within the framework of the South African EPI and already shows a positive impact in the elimination of HBsAg carrier rate in children<5 years.     

Adolescent booster with hepatitis B virus vaccines decreases HBV infection in high-risk adults

BackgroundNeutralizing antibodies (anti-HBs) after immunization with hepatitis B virus (HBV) vaccines against HBV surface antigen (HBsAg) wane after 10–15 years. We analyzed the effect of an adolescent booster given to vaccination-protected children born to mothers with different HBsAg-carrying status against HBV infection in their mature adulthood.MethodsA total of 9793 individuals, who were HBsAg-negative at childhood (baseline) and donated blood samples, both during childhood and adulthood, from the vaccination group in “Qidong Hepatitis B Intervention Study”, were enrolled. Among them 7414 received a one-dose, 10 μg-recombinant HBV vaccine booster at 10–14 years of age. At endpoint (23–28 years of age), we determined the HBV serological markers and quantified their serum HBV-DNA in each of the chronic HBV-infected adults.ResultsFifty-seven adults were identified as chronic HBV infection, indicated by HBsAg(+)&anti-HBc(+) for more than 6 months. The individuals who were born to HBsAg-positive mothers (high-risk adults) had significantly increased risk of developing chronic HBV infections in adulthood compared with those who were born to HBsAg-negative mothers; the adjusted odds ratio (OR) was 12.56, 95%CI:7.14–22.08. The seronegative status of anti-HBs at 10–11 years of age significantly increased the risk of HBV infections among the high-risk adults. When HBsAg(−)&anti-HBc(+) children who were born to HBsAg-positive mothers 70% of them remained as the status and 10% of them developed HBsAg(+)&anti-HBc(+). While when they were born to HBsAg-negative mothers 1.05% HBsAg(−)&anti-HBc(+) children developed HBsAg(+)&anti-HBc(+) and 24.74% of them remained as the status in 12–18 years. One dose of adolescent booster showed significant protection on high-risk adults from chronic HBV infection; P for trend was 0.015.ConclusionsMaternal HBsAg-positive status was an independent risk factor for vaccination-protected children to develop HBV breakthrough infection in adulthood. Adolescent boosters might be appropriate for high-risk individuals who were born to HBsAg-positive mothers when their serum anti-HBs < 10 mIU/ml.     

Community-based research: cost of the tests used for anti-HBc total seropositivity only and hepatitis B screening

Our study aimed to determine anti-HBc total (IgG+IgM) seroprevalence in the adult population aged ≥15 and to compare the cost of testing for HBsAg and anti-HBs in only anti-HBc positive (+) subpopulation to that in the whole population for HBV screening. The study involved a face-to-face survey and peripheral blood sampling from 452 adult subjects for HBV tests. HBV-DNA PCR was studied only in anti-HBc(+)subjects. Of the 452 subjects anti-HBc total was positive in 192 (42.47%), of which: (a) 27 (14.06%) were HBsAg(+), anti-HBs negative (-), (b) 126 (65.62%) were HBsAg(-), anti-HBs(+), (c) 39 were HBsAg(-), anti-HBs(-). This last group (c) were tested for HBV-DNA PCR and six (15.38%) were positive. When we perform HBsAg and anti-HBs tests in all 452 subjects as in routine practice in blood banks, the cost is 3320 Euros. However, when all subjects are tested for anti-HBc total at first and then only anti-HBc total(+) ones are tested for HBsAg and anti-HBs, the cost is 2929 Euros. The cost difference between the two methods is 391 Euros for 452 subjects. Accordingly, our HBV screening algorithm brings a financial saving of 11.78% and helps to identify the isolated anti-HBc total(+) subjects who carry potential risk for spreading HBV.     

Hepatitis B virus infection in adolescents in a rural township--15 years subsequent to mass hepatitis B vaccination in Taiwan

In Taiwan, decrease of both infection and carrier rates of hepatitis B virus (HBV) have been documented especially in metropolitan areas after universal HBV vaccination. This study investigated HBV infection status in a rural township 15 years after the program began. Three cross-sectional studies were conducted in 1999, 2000 and 2003, to recruit all the students of the only junior middle school, born from July 1984 to June 1991, in a township in central Taiwan. Serum samples were tested for HBsAg, anti-HBs and anti-HBc. Subjects identified to be neither positive for HBsAg nor anti-HBs were given a booster dose of HBV vaccine. Subjects lacking an anamnestic anti-HBs response were given a complete 3-dose vaccination. A total of 1454 (98.5%) students responded. The prevalence rate of HBsAg decreased 57% [from 12.5% in 1984 to 5.4% in 1991, P < 0.005 (chi2-test for linear trends)], and anti-HBc positive rate dropped 68% (from 31.9 to 10.2%, P < 0.001). An anamnestic anti-HBs response developed after a vaccine booster among 433 (72%) anti-HBs negative and 12 (66.7%) anti-HBc alone subjects. And 93 (94.9%) anti-HBs negative and 1 (16.7%) anti-HBc alone subject developed a primary anti-HBs response after catch-up vaccination. Viremia was detected for two anti-HBc alone subjects without anamnestic or primary response. The vaccination program has decreased the number of those infected and carrier rates in either urban or rural areas in Taiwan. However, the prevalence of HBsAg and anti-HBc in rural area were much higher than urban area.     

Impact of hepatitis B vaccination in a highly endemic area of south Italy and long-term duration of anti-HBs antibody in two cohorts of vaccinated individuals

The aims of this study were to evaluate the impact of hepatitis B vaccination on the changing pattern of HBV infection in a former hyperendemic area (Afragola, South Italy), and to assess the long-term persistence of anti-HBs in two cohorts of individuals vaccinated as infants 18 and 23 years ago. Our data shows a significant decline in the prevalence of hepatitis B virus (HBV) markers in the general population from 1978 to 2006 (HBsAg: 13.4% versus 0.91%; anti-HBc: 66.9% versus 7.6%; p<0.001). Data from two cohorts of vaccinees provides further evidence regarding the long-term persistence of vaccine-induced anti-HBs. Data here reported indicates that the implementation of vaccination had a great impact in the control and prevention of hepatitis B in Italy.     

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.     

2372例慢性无症状HBV携带者血清HBVM模式的转变规律分析

目的 研究乙型肝炎病毒（HBV）感染血清标记物（HBVM）模式的转变规律。方法 对2372例无症状HBV携带进行了2－11年（平均4．14年）血清HBVM模式的随访，随访期内不用任何抗病毒药。结果 最初HBVM模式为HBsAg、HBeAg、抗－HBc均阳性（简称“大三阳”）和HBsAg、抗－HBe、抗－HBc均阳性（简称“小三阳”），随访终点时分别有62．1％和67．4％保持原模式不变；而最初模式为“大二阳”（HBsAg、HBeAg均阳性）、“小二阳”（HBsAg、抗－HBc均阳性）、“单抗－HBc阳性”（单项抗－HBc阳性，其余4项均阴性）、“单HBsAg阳性”（HBsAg阳性，其余4项均阴性），随访终点时保持原模式不变的比率较低（分别为39．3％、32．4％、8．7％、5．6％）。小三阳或小二阳随访期间仍可出现病毒复制（HBsAg阳转）。HBsAg、HBeAg平均每年阴转率分别为1．16％、7．1％，抗－HBs、抗－HBe平均每年阳转率分别为0．63％、4．8％；HBeAg阴转率明显高于HBsAg阴转率（P＜0．01）；抗－HBe阳转率明显高于抗－HBs转阳率（P＜0．01）。在随访期出现ALT升高468例（19．7％），其中160例（6．7％）表现为急性肝炎发作。结论 慢性无症状HBV携带长期随访中不同的血清HBVM模式可相互转换，并可出现肝炎活动。HBsAg自然阴转率和抗－HBs的自然阳转率均较低。     

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.     

Efficacy of yeast-derived recombinant hepatitis B vaccine after being used for 12 years in highly endemic areas in China

Objective

To evaluate the long-term efficacy and duration of yeast-derived recombinant hepatitis B vaccine in hepatitis B virus (HBV)-endemic areas.

Method

A cross-sectional investigation was carried out in five HBV-endemic areas. Children who were born between 1997 and 2008 and vaccinated with yeast-derived recombinant hepatitis B vaccine were selected. Serum samples were taken to test HBV infection markers by microparticle enzyme immunoassay, and the results were compared to those before vaccination.

Results

7066 subjects were enrolled. The average adjusted hepatitis B surface antigen (HBsAg) prevalence was 1.02%. HBV core antibody (anti-HBc) prevalence was 3.54%. The overall percentage of HBsAg(−)&Anti-HBc(−)&Anti-HBs(+) was 61.34%. With time after immunization, the percentage annually decreases from 86.11% in 2008 to 49.80% in 1997. Geometric mean concentration (GMC) of anti-HBs decreased significantly annually. The portion of GMC = 100–999.9 mIU/ml was 48.0% in 2008, and decreased to 16.7% in 1997.

Conclusion

HBsAg prevalence decreased dramatically. This shows that the yeast-derived recombinant hepatitis B vaccine is effective and stable after being used for 12 years in HBV-endemic areas. It is not suggested to carry out booster immunization.     

Significance and anamnestic response in isolated hepatitis B core antibody-positive individuals 18 years after neonatal hepatitis B virus vaccination in Taiwan

Aim

To investigate the significance of isolated hepatitis B core antibody (anti-HBc) and to analyze the response to hepatitis B virus (HBV) booster vaccination in young adults with isolated anti-HBc who had been fully vaccinated with HBV vaccine as infants.

Materials and methods

We screened 1734 new university entrants who had been fully vaccinated against HBV in infancy for the presence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and anti-HBc upon university entry. Results positive for isolated anti-HBc were reconfirmed by testing for the presence of HBsAg and anti-HBc once more, and further evaluated for anti-HCV, anti-HIV, and HBV DNA status 6 months later. Students were also offered HBV booster vaccinations at that time. Geometric mean titers (GMT) of anti-HBs after one booster dose of HBV were compared between students with isolated anti-HBc and students with HBV naïve status.

Results

The overall prevalence of isolated anti-HBc in our student cohort was 1.2% (21 of 1734). No evidence of occult HBV infection was observed. A “booster” anamnestic response (anti-HBs titer ≥10 mIU/mL) was noted in 95% (20 of 21) of subjects with isolated anti-HBc. After re-measurement of anti-HBc, 13 (62%) of the 21 subjects with isolated anti-HBc were reclassified as having resolved HBV infection with a loss of anti-HBs. In the remaining 8 subjects (38%), isolated anti-HBc was determined to be false positive. The HBV status of these 8 subjects was HBV naïve due to the waning-off effect of anti-HBs of the neonatal HBV vaccination. There was no significant difference in anamnestic response to a single HBV booster dose of vaccine between students with isolated anti-HBc (n = 13) and those with HBV naïve (n = 323) status (GMT 50.6 vs 47.7 mIU/mL, P = 0.90).

Conclusion

The presence of isolated anti-HBc 18 years after HBV vaccination can be attributed to post-HBV infection with a loss of anti-HBs and to a decline in anti-HBs elicited by vaccine. A single HBV booster dose of vaccine is recommended for subjects with isolated anti-HBc who were fully vaccinated with HBV vaccine as infants. This finding needs to be replicated in further studies with larger cohorts.     

Antibody response to hepatitis B vaccine is independently associated with hepatitis B breakthrough infection among adults: Results from a three-year follow-up study in China

Hepatitis B breakthrough infection (HBBI) and its risk factors are rarely reported among adults in China. In 2009–2010 in three townships of China, hepatitis B vaccine (HepB) administration and anti-HBs detection after HepB were conducted among the residents aged 18–59 years. HBsAg, anti-HBs and anti-HBc were detected for these vaccinees in 2013. A total of 252 out of 4701 vaccinees turned to be positive for anti-HBc in 2013, but nobody was positive for HBsAg. The HBBI rate was 5.36% (95% CI 4.73, 6.04). The highest rate was found in age-group of 18–29 years (7.33%, 95% CI: 5.31, 9.82). The rate was significantly different by the residential townships (P < 0.001) and by the antibody response to HepB (P = 0.003). Multivariate analysis showed that anti-HBs response to HepB was the independent risk factor of HBBI. The study documents the association between hyporesponse to HepB and HBBI among adults. It also suggests more attention should be given to new HBV infection among young adults.     

Long-term efficacy of plasma-derived and recombinant hepatitis B vaccines in a rural township of Central Taiwan

Aims

To assess the differences of long-term efficacy between plasma-derived and recombinant hepatitis B virus (HBV) vaccines and the effectiveness of catch-up vaccination in adolescents with undetectable anti-HBs.

Methods

Before 1992, infants born in Taiwan were immunized using plasma-derived HB vaccine, and thereafter, by using recombinant HB vaccine. From the only junior middle school of a rural township in central–southern Taiwan, 1788 (93.7%) students from five cross-sectional screenings, grouping into three birth cohorts (Group I: born during 1984–1986, II: 1986–1992 and III: 1992–1995), were enrolled for checking HBsAg, anti-HBs and anti-HBc. Students with undetectable HBsAg and anti-HBs underwent a booster dose (2.5 ug) of recombinant HB vaccine (Engerix-B; GlaxoSmithKline, Rixensart, Belgium) and had anti-HBs re-checked 3 weeks later. Individuals who had remained undetectable for anti-HBs completed the other two doses of HB vaccines at 1 and 6 months later.

Results

The prevalence of HBsAg (11.4, 5.4 and 1.2%), anti-HBs (64.5, 44.1 and 36.0%) and anti-HBc (29.5, 12.5 and 4.4%) decreased from Group I to III (P < 0.001 for trends). After a booster dose, the positive rates of anti-HBs increased up to 80.5% (16% increase) in Group I, 81.0% (36.9% increase) in Group II, and 94.4% (58.4% increase) in Group III. The percentages of anamnestic response increased with a trend (P < 0.001). A total of 110 non-responders completed 3 doses of catch-up HB vaccination, but 3 cases (2.7%) of Group II, evoked primary vaccination response.

Conclusion

Recombinant vaccine showed predominant disappearance rate (62.7%) of anti-HBs 12–15 years after vaccination, but provided better anamnestic response after a booster dose. It also showed high success rate (97.3%) in catch-up vaccination in adolescents.     

无锡市城区20岁以上人群乙型肝炎病毒感染及免疫状况调查

目的 对江苏省无锡市城区20岁以上自然人群HBV感染与乙型肝炎(乙肝)疫苗接种关系进行研究.方法 按知情、自愿、随机的原则抽取无锡市20岁以上的自然人群3744名进行乙肝血清流行率和乙肝疫苗接种调查,采用ELISA和放射免疫分析法测定乙肝五项指标(HBsAg、抗-HBS、HBeAg、抗-HBe和抗-HBc).结果 3744名调查对象总HBV感染率经标化后为51.7%,HBsAg、抗-HBs、HBeAg、抗-HBe、抗-HBc阳性率经标化后分别为4.5%、48.5%、0.3%、3.5%、51.4%.30岁以下人群HBsAg阳性率最低,分别为2.9%和2.6%.抗-HBc阳性率男性显著高于女性(P<0.05),且随着年龄的增加而逐步升高(趋势χ2=256.2,P<0.001).该人群乙肝疫苗标化接种率为17.6%,随着年龄的增加接种率迅速下降(P<0.05).接种疫苗人群的HBsAg阳性率和HBV感染率明显低于未接种疫苗人群、抗-HBs阳性率则高于未接种人群(P值均<0.05).结论 成年人接种乙肝疫苗可以影响整个人群的HBV感染模式,在加强新生儿乙肝疫苗计划免疫同时,应进一步加强对成年人的乙肝疫苗免疫策略.     

Analysis of anti-HBs levels in healthcare workers over 10 years following booster vaccination for hepatitis B virus

In this study, we analyzed anti-HBs levels in 104 Japanese healthcare workers who received three booster HBV surface antigen (HBsAg) vaccines because 80 became anti-HBs-negative at a mean of 2.4 years after the primary vaccination and 24 did not respond to primary vaccination. Of the re-vaccinees, 96% achieved a level of 10 mIU/ml or more of anti-HBs (i.e. seroprotected), 1 month after booster vaccination. Although anti-HBs levels of re-vaccinees decreased as rapidly as those of primary immunized vaccinees, at 10 years post-booster, 64% of re-vaccinees maintained anti-HBs levels at 10 mIU/ml or higher. Our results suggest that the additional three-dose protocol of booster HBsAg vaccination is beneficial in maintaining a seroprotective level of anti-HBs until new immunogenic vaccination protocols are established.     

深圳市儿童乙型肝炎血清流行病学调查分析

目的探讨深圳市儿童乙型病毒性肝炎(简称乙肝)流行现状及乙肝疫苗应用效果。方法采用多阶段整群系统随机抽样方法抽取调查户,对深圳市1～14岁常住人口进行问卷调查并采血检测HBsAg、抗-HBs及抗-HBc。采用Epidata 3.2软件建立调查数据库,利用SPSS 16.0软件进行数据处理分析,两组之间率比较采用χ2检验,P<0.05为差异有统计学意义。结果调查1～14岁儿童1 653人,HBsAg阳性率2.06%,抗-HBs阳性率74.53%,抗-HBc阳性率5.32%,HBV感染率9.62%。有乙肝疫苗免疫史儿童1 349人,HBsAg阳性率1.85%、抗-HBs阳性率75.02%、抗-HBc阳性率4.60%及HBV感染率5.41%;无乙肝疫苗免疫史儿童92人,HBsAg阳性率4.35%、抗-HBs阳性率68.48%、抗-HBc阳性率10.87%及HBV感染率73.91%;有无乙肝疫苗免疫史儿童HBsAg阳性率、抗-HBs阳性率差异无统计学意义,抗-HBc阳性率、HBV感染率差异有统计学意义,(χ2=7.14、457.83,P均<0.01)。乙肝疫苗免疫3年以内儿童601人,其中HBsAg阳性率为0、抗-HBs阳性率73.71%、抗-HBc阳性率2.0%、HBV感染率2.0%;免疫7～9年183人,其中HBsAg阳性率5.46%、抗-HBs阳性率79.23%、抗-HBc阳性率8.74%、HBV感染率11.48%。乙肝疫苗不同免疫年限儿童抗-HBs阳性率差异无统计学意义,HBsAg阳性率、抗-HBc阳性率、HBV感染率差异有统计学意义(χ2=29.53、36.88、43.75,P均<0.01)。结论持续保持较高的乙肝疫苗接种率,可以有效降低乙肝流行率。研究和推行乙肝疫苗加强免疫策略也是乙肝防治工作重点之一。     

Hepatitis B markers in Gloucestershire firemen

Occupational exposure to blood and body fluids and the prevalenceof serological markers of hepatitis B virus (HBV) infectionwere studied in Gloucestershire firemen to assess the occupationalrisk of HBV infection. A high compliance was achieved (472/503,94 per cent). Cumulative occupational exposure to blood or bodyfluids rose progressively to 68 per cent after 24 years' service.No sera were positive for hepatitis B surface antigen (HBsAg).Six sera were positive for hepatitis B surface antibody (anti-HBs)and were tested for hepatitis B core antibody (anti-HBc). Thefour subjects who were positive for anti-HBs alone had all receivedHBV vaccine. Two sera contained both anti-HBs and anti-HBc.Therefore, 2/472 firemen (0.42 per cent) showed evidence ofprevious HBV infection, a similar proportion to that found ina recent study in UK blood donors (0.49 per cent). Despite considerableexposure to blood and body fluids, an occupational risk of hepatitisB infection was not found in Gloucestershire firemen.