中国中西部地区新生儿乙型肝炎疫苗首针及时接种状况调查

目的了解中国中西部地区新生儿乙型肝炎(乙肝)疫苗首针(HepB1)及时接种现况,探讨提高新生儿HepB1及时接种率的方法。方法按照卫生部/全球疫苗免疫联盟合作项目办公室的统一要求,2004年对22个项目省(自治区、直辖市,下同)27 459名2003年出生儿童,2005年对5个项目省10 843名2004年出生儿童、1 116名2005年出生儿童的HepB1及时接种情况开展现场调查。结果中西部地区新生儿HepB1及时接种率是:2004年出生儿童(81.55%)高于2003年出生儿童(74.01%);医院出生儿童(85.36%)高于在家出生儿童(19.00%);县级及以上医院出生儿童(88.27%)高于乡镇卫生院(71.74%)。结论中西部地区新生儿HepB1及时接种率正在逐年提高,同时也揭示提高在家出生、在乡镇卫生院出生儿童的HepB1及时接种率,是今后工作的重点。     

The sex ratio of children in relation to paternal preconceptional radiation dose: a study in Cumbria, northern England.

STUDY OBJECTIVE: To investigate whether the occupational exposure to external ionising radiation of men employed at the Sellafield nuclear installation, West Cumbria, affects the sex of the children they subsequently father. DESIGN: A retrospective cohort study using logistic regression to analyse the sex ratio, in particular in relation to paternal preconceptional irradiation. SETTING AND PARTICIPANTS: The 260,060 singleton births between 1950 and 1989 to mothers resident in Cumbria, north west England. RESULTS: The sex ratio among children of men employed at any time at Sellafield was 1.094 (95% CI: 1.060, 1.128), significantly higher than that among other Cumbrian children, 1.055 (95% CI: 1.046, 1.063). There was an increased sex ratio of 1.396 (95% CI: 1.127, 1.729) in the 345 children whose fathers were estimated from annual dose summaries to have received more than 10 mSv of external radiation in the 90 days preceding conception, but no significant linear trend between sex ratio and 90 day paternal preconceptional dose was found. There was no significant association between sex ratio and the external dose accumulated before the 90 day period preceding conception. CONCLUSIONS: Men employed at Sellafield fathered a greater proportion of boys than would be expected for a Cumbrian population, which may be partly explained by their younger age distribution. A greater effect was observed in the fathers with recorded doses exceeding 10 mSv in the 90 days before conception. While this may reflect a true statistical association, it is also possible that it may be a chance finding due to imprecision in the dose estimates and consequent misclassification.     

The risk of childhood cancer from intrauterine and preconceptional exposure to ionizing radiation.

The findings of studies investigating whether exposures to ionizing radiation before birth, either pre- or post-conception, increase the risk of childhood cancer have provoked much scientific controversy. An epidemiological association between the abdominal exposure of pregnant women to diagnostic X-rays and childhood cancer was first reported in the 1950s, while an association between the recorded dose of radiation received occupationally by fathers before the conception of their offspring and childhood leukemia was reported only recently in 1990. The scientific interpretation of these particular statistical associations is by no means straightforward, but the latest analyses of intrauterine irradiation and childhood cancer indicate that a causal inference is likely. Scientific committees have adopted risk coefficients for the intrauterine exposure of somatic tissues, which for childhood leukemia are comparable to those accepted for exposure in infancy, although questions remain about the level of risk of childhood solid tumors imparted by exposure to radiation in utero and shortly after birth. In contrast, the association between paternal preconceptional radiation dose and childhood leukemia has not been confirmed by studies using objectively determined doses. The original association has been found to be restricted to children born in one village, it does not extend to cancers other than leukemia, and it is markedly inconsistent with the established body of knowledge on radiation-induced hereditary disease. A causal interpretation of this association has effectively been abandoned by scientific authorities.     

Vaccine coverage in children born to migrant mothers in Australia: A population-based cohort study

BackgroundOverall, infant immunisation coverage is currently >90% in Australia, but there are pockets of under-immunised children including children from migrant backgrounds. This study aimed to examine whether on-time vaccination coverage of diphtheria-tetanus-pertussis dose 3 (DTP3) for children born in Australia differed by mother’s region of birth and if so, what factors were associated with these differences.MethodsWe conducted a population-based cohort study using linked data on perinatal, immunisation and birth records for 2 million children born in Western Australia and New South Wales between 1996 and 2012. We assessed on-time coverage of DTP3 (vaccination from 2 weeks prior to, and up until 30 days after, the due date) in children with mothers born overseas. Logistic regression models were developed to determine factors associated with on-time coverage for each maternal region of birth and all regions combined, adjusting for a range of demographic factors. Adjusted estimates of coverage were calculated for the different regions of birth.ResultsOn-time DTP3 coverage was 76.2% in children of Australian born mothers, lower in children of mothers from Oceania (66.7%) and North America (68%), and higher in children born to mothers from South-East Asia (79.9%) and Southern Asia (79.3%). While most variables were consistently associated with lower coverage in all regions of birth, higher socioeconomic status and jurisdiction of birth showed varied results. Adjusted estimates of DTP3 coverage increased in children born to mothers from Australia (78.3%), Oceania (70.5%), Northern Africa (81.5%) and the Middle East (79.6%). DTP3 coverage decreased in children born to mothers from Europe and former USSR (74.6%), North-east Asia (75.2%), Southern Asia (76.7%), North America (65.5) and South/Central America and the Caribbean (73.2%).ConclusionsOn-time vaccination rates differed by mother’s region of birth. More research is needed to determine the main reasons for these remaining differences to improve vaccine uptake and also help guide policy and practice.     

The risk of leukemia in Seascale from radiation exposure

An excess of leukemias in children has been observed between 1950 and 1980 in the village of Seascale (population about 3,000) which is situated approximately 3 km to the south of Sellafield nuclear fuel reprocessing plant in West Cumbria, England. Radiation doses from all the main sources of radiation exposure of the population and risks of radiation-induced leukemia have been calculated for children born and living in Seascale during the period of operation of the plant. For the Seascale study population of 1225 children and young persons, followed to age 20 y, or followed until 1980 for those born after 1960, 0.016 radiation-induced leukemias are predicted from the Sellafield discharges. This corresponds to an average risk to children in the population of about one in 75,000. For the four fatal leukemias observed in the study population (0.5 expected from United Kingdom statistics) to be attributed to the operations at Sellafield, the average risk would have to be increased by a factor of about 250, to one in 300. Although there is some uncertainty about the releases from the plant and concentrations of radionuclides in environmental materials in the Sellafield area, particularly for the early years of its operation, the possibility that the doses calculated and the risk coefficients used for radiation-induced leukemia could be so substantially wrong is very unlikely. The number of radiation-induced leukemias from all radiation sources is calculated to be 0.1, which corresponds to a risk of about one in 12,250 for the average child in the study population. About two-thirds of the risk is from natural radiation, 16% from the Sellafield discharges, and nuclear weapons fallout and medical exposure each contribute about 9%. The models used for calculating radiation doses from intakes of radionuclides were based upon those recommended by the International Commission on Radiological Protection (ICRP). This presented a number of difficulties in the assessment, which included the lack of any generally accepted age-related dosimetric models, particularly for bone-seeking radionuclides; limited information on gut transfer factors for radionuclides incorporated in foodstuffs; and no dosimetric models for the fetus. These and other problems identified in the analysis that require more information are discussed.     

Neighbourhood greenness and birth outcomes in a Swedish birth cohort – A short communication

The present study investigated whether associations between greenness and birth outcomes can be detected in children belonging to a Swedish birth cohort (BAMSE). Normalized difference vegetation index (NDVI) within a 500 m buffer zone around maternal address was used as estimate of greenness. Ordinary least squares and quantile regression models were performed to investigate associations between neighbourhood NDVI and birthweight (n = 2619), birth length (n = 2490) and head circumference (n = 2243). Logistic regression analyses were used to detect the association between NDVI and odds of being born as “small-” or “large-for-gestational-age”. There were no clear associations between NDVI and birth weight in the total sample. However, in a suburban sub-sample, increased NDVI levels were significantly associated with elevated birthweight of small new-borns (β_{2nd percentile} = 276 g, 95% CI 61 to 492, p = 0.012), and significantly reduced the odds ratio (OR) for children being born as small-for-gestational-age (OR = 0.31 95% CI 0.1 to 1, p = 0.049). No significant associations were found between NDVI and birth length or head circumference. In conclusion, neighbourhood greenness appears not to be associated with birthweight as such, but rather decrease the odds of being born underweight, in particular in suburban areas.     

Attention regulation in low‐risk very low birth weight preschoolers: the influence of child temperament and parental sensitivity

Even in the absence of major disabilities, children born prematurely are at high risk for academic delays and deficits. Research suggests that some differences in outcomes may relate to problems with self‐regulation, especially attention regulation. Previous research has demonstrated that individual differences in attention regulation is associated with both child and parent factors. This study examines the role of child temperament and parental sensitivity for attention regulation in preschool‐age children (n = 95) born with very low birth weights (VLBW) by using both questionnaire and observational data. Regression analyses demonstrate differential effects of specific child temperament characteristics and specific aspects of parental sensitivity on attention regulation. Early assessment of temperament and individualised parent sensitivity training may be important for improving outcomes for VLBW children.     

Duration of gestation, size at birth and later childhood behaviour

Although many previous studies have reported an association between preterm birth or small size at birth and later behaviour, multiple methodological limitations threaten the validity of causal inferences from reported associations. The authors have examined the association between gestational age and gestational age-specific size at birth (weight, length and head circumference) and behaviour in a large sample of children born healthy at term. The data were from the 6.5-year follow-up of 13,889 Belarusian children who participated in the Promotion of Breastfeeding Intervention Trial, a cluster-randomised trial of a breast-feeding promotion intervention. Child behaviour was measured using the parent and teacher versions of the Strengths and Difficulties Questionnaire (SDQ). Differences in SDQ scores by gestational age and by birthweight, birth length and birth head circumference standardised for gestational age and sex (z-scores) were analysed after controlling for potentially confounding maternal and family factors. There was no association between gestational age and child behaviour after adjusting for potential confounding factors. Lower birthweight-for-gestational age was associated with higher scores in problem behaviours including total difficulties, conduct problems, hyperactivity, emotional symptoms and peer problems. Similar but smaller differences were observed with birth length and birth head circumference, but those differences were attenuated with adjustment for birthweight. The patterns of association were consistent in both parent and teacher assessments. Among school-age children born at term within normal range of birthweight, fetal growth, but not gestational age, was associated with behavioural problem scores.     

Seasonality of birth for cancer in Northern England, UK

Environmental factors operating around the time of birth may influence the subsequent development of childhood cancer, particularly leukaemia. Certain factors may vary with season (e.g. infections), and we therefore investigated whether there was any evidence of seasonality of month of birth, based on data from 4199 children diagnosed with cancer under the age of 15 years. We extracted details of (i) children born 1960-95 and diagnosed 1968-95 from two population-based registries, covering the Northern (n = 2053) and Yorkshire (n = 1977) Regional Health Authority and (ii) children born in Cumbria 1950-93 and diagnosed anywhere in the UK before 1994 from a birth cohort database (n = 397). The following diagnostic categories were analysed: 0-14 years--all cancers, leukaemias, acute lymphoblastic leukaemias, central nervous system tumours, all other solid tumours; 1-6 years--leukaemias, acute lymphoblastic leukaemias. Seasonal variation was tested using Walter and Elwood's test, and logistic regression analysis allowing for cyclical variation in month of birth. No evidence of seasonality was present for any group except acute lymphoblastic leukaemia diagnosed among 1- to 6-year-olds. Seasonal trends varied by region: in the Northern and Cumbrian datasets, seasonality patterns were significant and similar (P < 0.05) with a predicted peak in early spring, whereas in Yorkshire there was less strong evidence of seasonality (P = 0.08) with a peak predicted in late summer. These findings suggest that local seasonal environmental factors operating around the time of birth are not associated with the totality of childhood cancer, but possible links with acute lymphoblastic leukaemia are supportive of a hypothesis of an infectious aetiology.     

Perinatal and maternal risk factors for autism spectrum disorders in New South Wales, Australia

Background This study was commenced in 1999 with the aim of examining risk factors for autism using established population‐based data for comparison. Methods Cases were ascertained using active surveillance and compared with birth data. Results Four risk factors were found to be significantly associated with autism using binary logistic regression analysis; being male [adjusted odds ratio (OR) 4.7, 95% confidence interval (CI) 3.2–7.0], being born prematurely (adjusted OR 2.2, 95% CI 1.5–3.5), having maternal age ≥35 years (adjusted OR 1.7, 95% CI 1.2–2.4) and having a mother born outside Australia (adjusted OR 1.4, 95% CI 1.0–1.9). For analysis completed for pregnancies, rather than live births, multiple birth was also a significant risk factor for one or more children of the pregnancy to be affected by autism (adjusted OR 2.5, 95% CI 1.1–5.5). There was a statistically significant trend towards increasing risk with increasing risk factor ‘dose’ for gestational age (P = 0.019), multiple birth (P = 0.016) and maternal age (P < 0.001). For mother's country of birth the group with the highest risk were children of mother's born in south‐east or north‐east Asia. There was a non‐significant trend towards a higher proportion of children with developmental disability having risk factors. Conclusion Replication of risk factors from previous studies and a significant risk factor ‘dose’ effect add to growing evidence that maternal and perinatal factors are low magnitude risk factors for autism. The association between developmental disability and autism risk factors warrants further examination.     

Prematurity as a predictor of childhood asthma among low-income children

PURPOSE: The purpose of this study was to evaluate the association among birth weight, prematurity, and the prevalence of asthma later in childhood and to assess the degree to which this association may differ between black and white children. METHODS: Michigan Medicaid claims data from 2001 through 2003 were analyzed to determine asthma prevalence for 150,204 children between ages 5 and 18 years. Asthma cases were identified using Healthcare Effectiveness Data and Information Set persistent asthma criteria and included children having claims for any of the following services within a calendar year: at least one inpatient or one emergency department (ED) claim with an asthma primary diagnosis; at least four asthma medication-dispensing events; or at least four outpatient visits with an asthma diagnosis, and at least two asthma medication-dispensing events. Birth weight and gestational age from birth certificate data were matched with Medicaid files to determine size-for-gestational-age criteria. RESULTS: Overall, 8.3% of children had persistent asthma; black children had slightly higher asthma prevalence (8.6%) than white children (7.8%; odds ratio [OR]=1.11, 95% confidence interval [CI]: 1.07-1.15). Children born very preterm (相似文献   

Feasibility of an epidemiologic study of thyroid neoplasia in persons exposed to radionuclides from the Hanford nuclear facility between 1944 and 1956

Between 1944 and 1956, approximately 19.6 PBq (530,000 Ci) of 131I were released to the atmosphere during Pu reprocessing for nuclear weapons at the Hanford nuclear facility in southeastern Washington state. For these years, we summarized historical records of quarterly 131I atmospheric releases and vegetation concentrations measured in nearby communities. We used these data and other reported environmental measurements to make preliminary estimates of maximum doses to the thyroid for the general public. We also computed the statistical power for an epidemiologic study of thyroid neoplasia in birth cohorts of children born in two counties near Hanford during the years of highest exposure. These estimates suggest that an epidemiologic study would be feasible if the actual average radiation doses in the exposed population were no less than one-tenth the preliminary maximum doses. Our analyses also suggest that it may be more appropriate to stratify the exposed population by cumulative dose in order to examine the relation between radiation exposure and thyroid neoplasia.     

Genetic effects of radiotherapy for childhood cancer

Radiation-induced heritable diseases have not been demonstrated in humans and estimates of genetic risks for protection purposes are based on mouse experiments. The most comprehensive epidemiologic study is of the Japanese atomic bomb survivors and their children, which found little evidence for inherited defects attributable to parental radiation. Studies of workers exposed to occupational radiation or of populations exposed to environmental radiation appear too small and exposures too low to convincingly detect inherited genetic damage. In contrast, survivors of childhood cancer form the largest group of people exposed to high doses of ionizing radiation before reproduction and offer unique advantages for studying trans-generation effects. A wide range of gonadal doses are possible, several comparison groups are readily available (including siblings), and there is a strong willingness among cancer survivors to participate in health studies. Cancer patients also have detailed medical records that facilitate both the accurate estimation of gonadal doses and the assessment of potentially confounding factors, such as intercurrent illness, personal and family medical histories, lifestyle characteristics such as tobacco use, and circumstances at delivery. An international study is nearing completion of over 25,000 survivors of childhood cancer in the United States and Denmark who gave birth to or fathered over 6,000 children. Doses to gonads are being reconstructed from radiotherapy records with 46% over 100 mSv and 16% over 1,000 mSv. Adverse pregnancy outcomes being evaluated include major congenital malformations, cytogenetic abnormalities, stillbirths, miscarriages, neonatal deaths, total deaths, leukemia and childhood cancers, altered sex ratio, and birth weight. The main analyses are based on dose-response evaluations. Blood studies of trios (cancer survivor, spouse or partner and offspring) have been initiated to evaluate mechanistic evidence for the transmission of any radiation-induced genetic damage such as minisatellite mutations. Markers of cancer susceptibility such as chromosomal radiosensitivity and genotype profile will also be examined. In the United States series to date, 4,214 children were born to cancer survivors among whom 157 (3.7%) genetic diseases were reported in contrast to 95 (4.1%) reported conditions among 2,339 children born to sibling controls. In the Denmark series the comparable figures were 82 (6.1%) birth defects among 1,345 children of cancer survivors and 211 (5.0%) among 4,225 children of sibling controls. Coupled with prior studies, these preliminary findings, if sustained by ongoing dose-response analyses, provide reassurance that cancer treatments including radiotherapy do not carry much if any risk for inherited genetic disease in offspring conceived after exposure.     

Tocolytic magnesium sulfate exposure and risk of cerebral palsy among children with birth weights less than 1,750 grams

The authors examined the relation between intrapartum magnesium sulfate exposure and risk of cerebral palsy in a case-control study of low birth weight children designed to control for confounding by the clinical indications for magnesium in pregnancy. Case children (n = 97) included all singleton children with cerebral palsy who were born in 1985-1989 in Atlanta, Georgia with a birth weight less than 1,750 g and whose mothers had not had a hypertension-related disease during pregnancy. Control children (n = 110) were randomly selected from the infant survivors using identical selection criteria. Data on magnesium sulfate exposure, labor and delivery, and infant characteristics were abstracted from hospital records. The authors found no association between exposure to magnesium sulfate and cerebral palsy risk (odds ratio = 0.9; 95% confidence interval: 0.3, 2.6) either in all children or in subgroups with varying likelihoods for exposure to magnesium. However, the association did vary by birth weight, with a protective effect being seen in children born weighing less than 1,500 g and an elevated risk in children with birth weights of 1,500 g or more; all confidence intervals included 1.0 except for the combined <1,500 g group. Several ongoing randomized clinical trials of magnesium and cerebral palsy may shed more definitive light on this relation.     

Born out of wedlock and never married--it breaks a man's heart

This study examines whether men who were born outside marriage in early twentieth century Sweden run a higher risk of dying from ischaemic heart disease (IHD) in middle and old age compared to men who were born inside marriage. Analyses are based on the male half of the Uppsala Birth Cohort Study, Sweden, consisting of all 7411 boys who were born alive at the Uppsala Academic Hospital during the period 1915-1929. The statistical method used is Cox regression. The results demonstrated a statistically significant excess mortality among men born outside marriage, which could not be explained by either social class of origin or birth weight for gestational age. Instead, this elevated mortality was largely explained by the more than doubled mortality risk among those men born outside wedlock who never married in relation to the corresponding group of men born to married parents. Even when three indicators of adult socio-economic status were adjusted for, men who never married and were born outside marriage still ran a 93 per cent higher risk of dying from IHD than men who never married but were born inside marriage. This intervening effect of adult marital status was restricted to the category of never married men. Thus, although divorcees demonstrated an even higher mortality risk in relation to the married than did those who never married, this was equally true for men born inside and men born outside marriage. In the concluding section of the paper I argue that these findings should be understood in terms of the childhood social stigma that the illegitimate children experienced. This stigma may have resulted in an increased susceptibility, which in combination with the "failure" in adulthood to comply with the established norms of society regarding matrimony led to higher levels of IHD mortality in middle and old age.     

克拉玛依市在医院出生的新生儿首剂乙型肝炎疫苗未及时接种原因分析

目的分析克拉玛依市在医院出生的新生儿首剂乙型肝炎疫苗（First Dose Hepatitis B Vaccine,HepB．）未及时接种的原因,为提高新生儿HepB,及时接种率提供参考。方法采取回顾性调查分析方法,系统收集克拉玛依市2004～2010年所有在医院出生的新生儿的HepB,接种资料,对未及时接种HepB,的原因进行分析。结果克拉玛依市2004～2010年在医院出生的新生儿共20159人,HepB,及时接种率95．19％;不同年份HepB,及时接种率的差异有统计学意义（z。=289．29,P〈0．01）;不同地区在医院出生新生儿HepB,及时接种率的差异无统计学意义（X^2=2．84,P〉0．05）;在不同医院出生的新生儿HepB,及时接种率的差异有统计学意义（X^2=121．54,P〈0．01）。在医院出生的新生儿未及时接种HepB．的主要原因是新生儿疾病,占34．98％;其次为早产占26．73％,低体重占20．23％,窒息占13．31％,监护人拒绝接种和自动离院占4．75％。结论影响克拉玛依市在医院出生的新生儿HepB。未及时接种的主要原因是接种人员对HepB,接种禁忌证的把握过度严格,应加强对接种人员相关知识的培训,提高在医院出生新生儿的HepB,及时接种率。     

Obstetric outcomes in West Cumberland Hospital: is there a risk from Sellafield?

A retrospective study was made of the obstetric outcome of 18,252 babies born in West Cumberland Hospital in the years 1975 to 1985. There were 934 premature births (before 37 weeks), 555 small for dates births (under 2.5 kg but not before 37 weeks), 167 stillbirths, 125 neonatal deaths and 236 reported congenital malformations. The 212 babies born to mothers from Seascale during that time were compared with the births to mothers from other areas in West Cumbria Health District in order to assess any adverse effect from possible radioactive discharge at nearby Sellafield. There was no evidence of any increased incidence of these outcomes in Seascale births. Adequate retrospective data on miscarriage rates were not available, but using indirect information on hospital inpatients, no statistically significant increased incidence was found, although the absolute numbers of miscarriage in Seascale were slightly higher than expected. From this evidence, no adverse effects on completed pregnancies can be attributed to the Sellafield plant of British Nuclear Fuels. However, a prospective study of miscarriage incidence in West Cumbria and near other nuclear installations is urgently needed.     

中国2014年HBsAg阳性母亲所生1～14岁儿童乙型肝炎血清流行病学特征分析

目的 分析HBsAg阳性母亲所生1～14岁儿童乙肝血清流行病学特征。方法 以2014年全国乙型肝炎（乙肝）血清流行病学调查中母亲HBsAg阳性的1～14岁儿童作为研究对象,采用SPSS 18.0软件分析不同性别、年龄、民族、出生地点、城乡、地区的儿童HBsAg、抗-HBs、抗-HBc阳性率以及HBsAg、抗-HBs影响因素等。结果 共分析HBsAg阳性母亲所生的1～14岁儿童645人,HBsAg、抗-HBs、抗-HBc阳性率分别为3.41%（22/645）、71.94%（464/645）、7.60%（49/645）。其中,1～、3～、5～、10～14岁组HBsAg阳性率分别为1.27%（3/236）、3.23%（6/186）、5.71%（8/140）、6.02%（5/83）,抗-HBs阳性率分别为85.17%（201/236）、69.35%（129/186）、56.43%（79/140）、66.27%（55/83）,抗-HBc阳性率分别为4.66%（11/236）、5.38%（10/186）、11.43%（16/140）、14.46%（12/83）。多因素logistic分析结果显示,出生地点、首针乙型肝炎疫苗（HepB）接种时间是影响HBsAg阳性母亲所生儿童HBsAg阳性率的主要因素,在医院外出生儿童HBsAg阳性率高于在医院内出生者（OR=7.47,95%CI：1.50～37.25）,首针HepB出生后> 24 h接种儿童HBsAg阳性率高于出生后≤24 h接种者（OR=6.21,95%CI：2.15～17.99）。结论 我国乙肝母婴阻断取得一定成效。住院分娩和首针HepB及时接种仍是新生儿乙型肝炎母婴阻断工作的重点。     

A reduction in chronic hepatitis B virus infection prevalence among children in Vietnam demonstrates the importance of vaccination

Background

Vietnam has high endemic hepatitis B virus infection with >8% of adults estimated to have chronic infection. Hepatitis B vaccine was first introduced in the national childhood immunization program in 1997 in high-risk areas, expanded nationwide in 2002, and included birth dose vaccination in 2003. This survey aimed to assess the impact of Vietnam's vaccination programme by estimating the prevalence of hepatitis B surface antigen (HBsAg) among children born during 2000–2008.

Methods

This nationally representative cross-sectional survey sampled children based on a stratified three-stage cluster design. Demographic and vaccination data were collected along with a whole blood specimen that was collected and interpreted in the field with a point-of-care HBsAg test.

Results

A total of 6,949 children were included in the survey analyses. The overall HBsAg prevalence among surveyed children was 2.70% (95% confidence interval (CI): 2.20–3.30). However, HBsAg prevalence was significantly higher among children born in 2000–2003 (3.64%) compared to children born 2007–2008 (1.64%) (prevalence ratio (PR: 2.22, CI 1.55–3.18)). Among all children included in the survey, unadjusted HBsAg prevalence among children with ≥3 doses of hepatitis B vaccine including a birth dose (1.75%) was significantly lower than among children with ≥3 doses of hepatitis B vaccine but lacked a birth dose (2.98%) (PR: 1.71, CI: 1.00–2.91) and significantly lower than among unvaccinated children (3.47%) (PR: 1.99, CI: 1.15–3.45). Infants receiving hepatitis B vaccine >7 days after birth had significantly higher HBsAg prevalence (3.20%) than those vaccinated 0-1 day after birth (1.52%) (PR: 2.09, CI: 1.27–3.46).

Conclusion

Childhood chronic HBV infection prevalence has been markedly reduced in Vietnam due to vaccination. Further strengthening of timely birth dose vaccination will be important for reducing chronic HBV infection prevalence of under 5 children to <1%, a national and Western Pacific regional hepatitis B control goal.     

Factors associated with effectiveness of the first dose of hepatitis B vaccine in China: 1992–2005

Background

In China, the prevalence of chronic hepatitis B infection was high because of perinatal and early childhood transmission. A three-dose hepatitis B vaccine schedule with a first dose as soon as possible after birth was introduced in 1992 and generalized in 2002 in the Expanded Programme of Immunization (EPI). In 2006, a serological survey evaluated the effectiveness of vaccination.

Methods

We conducted a restricted analysis of the national serological survey that sampled children and collected information on demographic characteristics, birth history, hepatitis B vaccination and hepatitis B surface antigen (HBsAg) status as determined by ELISA testing. We compared children who received the first dose in a timely way (i.e., within 24 h of birth) with others in terms of HBsAg status, stratified by birth cohort and place of birth.

Results

Three-dose hepatitis B vaccine coverage increased from 60.8% for children born in 1992–1997 to 93.2% for children born in 2002–2005. Meanwhile, timely birth dose coverage increased from 38.7% to 74.4%. Among 29,410 children born in 1992–2005 who had received three vaccine doses and no hepatitis B immune globulin, factors associated with being HBsAg-negative in multivariate analysis included receiving a timely birth dose (p = 0.04), birth after 1998 (p < 0.001), living in an urban setting (p = 0.008) and hospital birth (p = 0.001). The relative prevalence of HBsAg among children receiving the timely birth dose was lower for children born in county or larger hospitals (0.39), intermediate in township hospitals (0.73) and highest at home (0.87).

Conclusions

Hospital birth and receiving a timely birth dose are the main determinants of the field effectiveness of the first dose of hepatitis B vaccine. Efforts to increase the proportion of hospital deliveries are key to increasing timely birth dose coverage and its effectiveness.