Susceptibility to rubella among pregnant women and the serological evidence of congenital rubella in newborn babies at Colombo South Teaching Hospital

OBJECTIVE: To determine the susceptibility to rubella infection in early pregnancy and the incidence of seropositivity of cord blood for rubella specific IgM among the newborn babies at Colombo South Teaching Hospital. METHODS: 1000 cord blood samples and 500 maternal blood samples from pregnant women before the 16th week of gestation were taken from the labour room and the antenatal clinic of the University Unit, Colombo South Teaching Hospital during the period of February 1999 to February 2001. These samples were tested for rubella specific IgM and IgG antibodies by ELISA. A detailed questionnaire was filled during the time of sampling. RESULTS: Of the 500 antenatal blood samples 82% were positive for rubella specific IgG. 373(75%) women gave a history of vaccination against rubella before their present pregnancy. Among the vaccinated 2(0.5%) were negative for IgG antibodies by ELISA. Out of 127 unvaccinated women 12(9%) gave a history of past infection with rubella and of this 3(25%) were seronegative for rubella specific IgG. 18% of pregnant women at 16 weeks of gestation were at risk of giving birth to a baby with congenital rubella syndrome. Among the tested 1000 cord blood samples three were seropositive (0.3%) for rubella specific IgM. CONCLUSIONS: A significant proportion of pregnant women were susceptible to rubella infection in the studied population. The present strategy of selective rubella vaccination should be reconsidered if we are to get closer to eliminating rubella syndrome in Sri Lanka.     

哈尔滨市妊娠妇女风疹病毒感染的筛查及分析

目的 调查2000年哈尔滨市妊娠妇女风疹病毒感染情况，方法 收集60例妊娠8－24周孕妇血清，采用酶联免疫吸附法（ELISA）检测风脊特异性IgM抗体，对该人群的风疹病毒感染率进行调查。结果 21例正常妊娠组血清样本的阳性率为4.76%，39例异常妊娠组血清样本阳性率为17.95%，两组数值经统计学处理x^2=7.33，P＜0.05，有显著性差异。结论 风疹病毒感染是造成异常妊娠的主要原因之一，妊娠早期进行风疹病毒感染的检测，对降低先天性风疹综合征患儿的出现具有重要意义。     

Rubella vaccination programme in Malaysia: analysis of a seroprevalence study in an antenatal clinic

In many developed countries, the incidence of rubella and congenital rubella syndrome (CRS) is considered to be negligible due to the availability of an effective vaccine. However, in Malaysia, several CRS cases are seen every year. This casts doubt on the effectiveness of the rubella vaccination programme. Very few seroprevalence studies were done over the years, making it difficult to discuss the effectiveness of the vaccination programme. The objective of this study is to determine the prevalence of rubella immunity among pregnant women attending antenatal clinics in a local teaching hospital. The hospital database on rubella immunity was assessed retrospectively from August 2001 to June 2002. A cross-sectional study of interviewed method as well as determination of rubella immunity by laboratory tests were carried out in July 2002. A total of 414 women were included, of whom 134 women were interviewed. The rubella immunity status was 92.3%. Based on this figure, rubella vaccination programme in Malaysia is a success despite the presence of CRS cases. Malaysia must ensure rubella vaccine coverage among target groups is high in order to minimise CRS cases.     

Effect of selective vaccination on rubella susceptibility and infection in pregnancy

The effect of school and adult vaccination on susceptibility to rubella in women of childbearing age was assessed in the Manchester area, where the population attending antenatal clinics is over 40 000 a year. Between 1979 and 1984 the proportion susceptible fell from 6.4% to 2.7%. In 1984, 4.2% of nulliparous women were susceptible compared with 1.4% of women in their second or subsequent pregnancy. Eighty five per cent of pregnant women screened and found to be non-immune were vaccinated post partum before leaving hospital. Requests for prevaccination screening of non-pregnant women increased in response to a national campaign and at the time of local outbreaks of rubella but only two thirds of those found to be nonimmune were subsequently vaccinated. During 1983 and 1984 infection was confirmed in 57 pregnant women--2% of those non-immune. Selective vaccination has reduced susceptibility to rubella in the childbearing population, but it is suggested that mass vaccination of children of both sexes should be added to the existing policy to control circulation of wild rubella virus and reduce the risk of infection to pregnant women who remain susceptible.     

Can we prevent an increase in the incidence of congenital rubella syndrome in the next decade?

The immunity to rubella of 115 girls aged 10 to 14 years was tested in 1978. The proportion of girls found to be immune was 80%, similar to rates in the prevaccination era. Nearly half of the immunity was from documented vaccination, and the other half was presumably from infection with wild rubella virus. The vaccination failure rate was 12%. Because of declining immunity to rubella of women of child-bearing age, detecting low levels of immunity in these women is becoming increasingly important. Immunization of 12- to 15-month-old children has not been effective. Vaccinating all girls 10 to 12 years old would likely be the most effective method of preventing an increase in the incidence of congenital rubella syndrome in the next decade.     

Guide to the management of rubella problems.

Despite the availability of rubella vaccine the incidence of the congenital rubella syndrome has been increasing in certain regions of Canada. Perhaps this is not surprising in view of the known irregular cyclic activity of rubella virus in a community and the fact that the percentage of seropositive women of childbearing age has not changed appreciable since the vaccine was introduced. Clearly vaccine is not being administered to sufficient numbers of women at risk. Until a much higher percentage of women of childbearing age possess rubella antibody, the costly problem of congenital rubella syndrome is likely to be with us. Common rubella problems relate to four categories: the exposed pregnant woman, laboratory diagnosis, the infant with suspected congenital rubella and the vaccine. One of the most common questions about the vaccine is the following: Can recently vaccinated individuals disseminate vaccine and infect seronegative contact? The answer is No.     

乌鲁木齐市三所医院孕产妇及其新生儿弓形体感染情况调查

为了摸清孕产妇弓形体感染情况,我们采用间接血凝(IHA)法,对乌鲁木齐市三所医院妇产科及门诊收集的126对母婴和133份不同孕周的孕妇血清进行了弓形体流行病学调查。结果孕产妇的弓形体抗体流行率为7.34％,新生儿弓形体抗体流行率为6.35％。将不同民族孕产妇的抗体流行率作比较,少数民族的高于汉族。在不同职业孕妇中,以农民的抗体流行率为最高。     

Seroepidemiologic study of rubella in selected Chinese female

To have a better understanding of rubella seroepidemiology among female population in Taiwan, we report a serologic survey of 4030 examinations for 2030 school girls and 2000 pregnant women, using enzyme-linked immunosorbent assay for the detection of rubella specific IgG. RA 27/3 vaccines were given to susceptible volunteer students and postpartum women for the evaluation of vaccine efficiency and its side effects. The results showed that the rubella susceptible female among 8 to 22-year-old girl students was 44.97%, which was higher than expected, as most of them experienced the outbreak of rubella in 1977. The susceptibility rate among the pregnant women was 19.35%, which was also higher than expected for an age group having been through two outbreaks in the past. All the vaccinees showed good tolerance to the vaccine and the seroconversion rate was 100%. With such high susceptibility rate among women of child bearing age and girl students, plus the endemic property of rubella infection in Taiwan, we can expect a high risk of congenital rubella syndrome. Mass vaccination against rubella should be brought into effect immediately.     

A large rubella outbreak with spread from the workplace to the community

CONTEXT: Childhood vaccination has reduced rubella disease to low levels in the United States, but outbreaks continue to occur. The largest outbreak in the past 5 years occurred in Nebraska in 1999. OBJECTIVES: To examine risk factors for disease, susceptibility of the risk population, role of vaccine failure, and the need for new vaccination strategies in response to the Nebraska rubella outbreak. DESIGN, SETTING, AND PATIENTS: Investigation of 83 confirmed rubella cases occurring in Douglas County, Nebraska, between March 23 and August 24, 1999; serosurvey of 413 pregnant women in the outbreak locale between October 1998 and March 1999 (prior to outbreak) and April and November 1999 (during and after outbreak). MAIN OUTCOME MEASURES: Case characteristics, compared with that of the general county population; area childhood rubella vaccination rates; and susceptibility among pregnant women before vs during and after the outbreak. RESULTS: All 83 rubella cases were unvaccinated or had unknown vaccination status and fell into 3 groups: (1) 52 (63%) were young adults (median age, 26 years), 83% of whom were born in Latin American countries where rubella vaccination was not routine. They were either employed in meatpacking plants or were their household contacts. Attack rates in the plants were high (14.4 per 1000 vs 0. 19 per 1000 for general county population); (2) 16 (19%), including 14 children (9 of whom were aged <12 months) and 2 parents, were US-born and non-Hispanic, who acquired the disease through contacts at 2 day care facilities (attack rate, 88.1 per 1000); and (3) 15 (18%) were young adults (median age, 22 years) whose major disease risk was residence in population-dense census tracts where meatpacking-related cases resided (R(2) = 0.343; P<.001); 87% of these persons were born in Latin America. Among pregnant women, susceptibility rates were 13% before the outbreak and 11% during and after the outbreak. Six (25%) of 24 susceptible women tested were seropositive for rubella IgM. Rubella vaccination rates were 90.2% for preschool children and 99.8% for school-aged children. CONCLUSIONS: A large rubella outbreak occurred among unvaccinated persons in a community with high immunity levels. Crowded working and living conditions facilitated transmission, but vaccine failure did not. Workplace vaccination could be considered to prevent similar outbreaks. JAMA. 2000;284:2733-2739.     

Absence of cell-mediated immunity to rubella virus 5 years after rubella vaccination.

The long-term effectiveness of rubella vaccination in childhood is particularly important because the ultimate goal of immunization is the prevention of infection during pregnancy. Of 25 healthy children tested 4 to 5 years after rubella vaccination, 19 showed no evidence of cell-mediated immunity (CM) to rubella virus despite the presence of hemagglutination-inhibition or complement-fixation antibodies or both. Twenty-two of 25 seropositive, naturally infected young adults showed evidence of CMI. These results indicate that fetuses of women who have been vaccinated against rubella may not be protected against damage by wild rubella infection during the pregnancy, when CMI is physiologically depressed.     

Intrauterine diagnosis of cytomegalovirus and rubella infections by amniocentesis.

OBJECTIVE: To establish a correlation between the presence of cytomegalovirus (CMV) or rubella virus in amniotic fluid obtained through amniocentesis and fetal infection. DESIGN: Case series. SETTING: Five hospitals in the Montreal region. Virology testing was done at the Virology Research Centre, Institut Armand-Frappier, Laval, Que. PATIENTS: Thirteen pregnant women infected with CMV, 3 with rubella, their 15 babies and 2 fetuses. Twelve of the women with CMV infection were recruited from a prospective study of CMV infection in pregnancy. Infection in the other women was detected through routine laboratory diagnostic testing. INTERVENTION: Amniotic fluid samples were cultured for CMV and rubella virus. Congenital infection of the neonates was established through isolation of either virus from pharyngeal mucus and urine specimens collected during the first 3 days of life or from fetal tissue if the pregnancy was terminated. MAIN RESULTS: CMV was cultured from the amniotic fluid of three of the CMV-infected women and from the pharyngeal mucus and urine specimens of their infants. Of the three women with rubella the amniotic fluid of one (who had a twin pregnancy) was positive for rubella virus. After the in-utero death of one fetus she underwent a therapeutic abortion of both. Examination of fetal tissue indicated that both fetuses had been infected with rubella virus. Each of the two other women with rubella gave birth to an uninfected, healthy infant. CONCLUSIONS: We found a strong correlation between the isolation of CMV or rubella virus from the amniotic fluid and the presence of congenital infection. This suggests that amniocentesis used to detect the presence of a virus is a useful method for the diagnosis of fetal infection.     

Some current issues relating to rubella vaccine

At the time of licensure in 1969, available data indicated that rubella vaccines were safe, noncommunicable, and effective. Since vaccine virus could cross the placenta and infect the fetus, cautious use of the vaccines in childbearing-age women was recommended. Over the past 15 years, additional information about the vaccines has been accumulated. This article provides an update of data on (1) the risk and degree of joint symptoms following vaccination and revaccination, (2) the duration of vaccine-induced immunity, (3) the protective effect of low levels of vaccine-induced antibody, and (4) the risks to the fetus following maternal vaccination. The data support continued vaccination of all young children as well as increased efforts to vaccinate susceptible adolescents and young adults, especially women. Only by more effective vaccination of the latter can elimination of congenital rubella syndrome be hastened.     

实时荧光定量RT-PCR与ELISA检测孕妇血清风疹病毒的比较分析

目的应用TaqMan实时荧光定量RT-PCR技术定量检测孕妇血清标本中风疹病毒RNA,并与ELISA法比较其敏感度与特异度,为孕妇早期风疹病毒检测提供迅速准确的方法。方法收集126例已确诊风疹病毒阳性孕妇血清标本与107例女性健康查体者血清标本,同时进行实时荧光定量RT-PCR核酸检测与风疹病毒ELISA法IgM抗体检测,比较两种方法的敏感度与特异度。结果以细胞培养法为金标准,实时荧光定量RT-PCR法敏感度为92.9%,特异度为98.1%。ELISA IgM抗体法的敏感度和特异度分别为97.6%,86.9%。两种方法的敏感度无显著性差异（p〉0.05）,实时荧光定量RT-PCR法的特异度明显高于ELISA IgM抗体法（p〈0.01）。结论实时荧光定量RT-PCR简便快捷、敏感性高、特异性高、定量准确,在临床风疹病毒基因检测中具有很大的应用潜力。     

风疹易感人群婚前风疹疫苗接种预防先天性风疹综合征

目的探讨婚前风疹易感人群风疹疫苗接种在提高孕妇对风疹的免疫力,预防先天性风疹综合征中的作用.方法对10 913例婚前风疹病毒抗体IgG阴性者给予国产风疹减毒活疫苗注射.3个月随防671例,比较风疹疫苗接种前后该地区孕妇近期风疹感染的发病率.结果818例风疹病毒抗体IgG阴性者接种后抗体转阳率为99.8%.风疹疫苗接种前后3年孕妇近期风疹感染率分别为0.37%及0.08%,有明显下降,有非常显著差异(P＜0.001).结论应用国产风疹减毒活疫苗对婚前易感人群作预防接种可提高育龄妇女对风疹的免疫力,降低孕期风疹感染的发生率,是预防先天性风疹综合征及风疹致畸的有效、安全措施.     

Congenital rubella in babies of south Asian women in England and Wales: an excess and its causes

The incidence of congenital rubella was found to be 2.3 times higher in Asian than non-Asian births in England and Wales. This was attributed in part to higher susceptibility to rubella in Asian than non-Asian women, as shown by antenatal serological data from public health laboratories in Leeds, Luton, and Manchester. Examination of the ethnic origin of pregnant women requesting laboratory testing after contact with rubella or rash and of women with laboratory confirmed rubella in pregnancy also suggested that the disease was being underdiagnosed in pregnant Asian women. Failure to prevent congenital rubella by termination of infected pregnancies may therefore contribute to the increased incidence of the syndrome in Asians. Health education programmes about the dangers of rubella in pregnancy and of the need for vaccination can readily be promoted in the Asian community through existing ethnic organisations. Protection of other ethnic minorities likely to be at similar increased risk may require a vaccination programme aimed at national elimination of rubella.     

Evaluation of rubella screening in pregnant women

BACKGROUND: The rationale for rubella vaccination in the general population and for screening for rubella in pregnant women is the prevention of congenital rubella syndrome. The objective of this study was to evaluate the effectiveness of the prenatal rubella screening program in Quebec. METHODS: A historical cross-sectional study was designed. Sixteen hospitals with obstetric services were randomly selected, 8 from among the 35 "large" hospitals in the province (500 or more live births/year) and 8 from among the 50 "small" hospitals (fewer than 500 live births/year). A total of 2551 women were randomly selected from all mothers of infants born between Apr. 1, 1993, and Mar. 31, 1994, by means of stratified 2-stage sampling. The proportions of women screened and vaccinated were ascertained from information obtained from the hospital chart, the physician's office and the patient. RESULTS: The overall (adjusted) screening rate was 94.0%. The rates were significantly different between large and small hospitals (94.4% v. 89.6%). Five large hospitals and one small hospital had rates above 95.0%. The likelihood of not having been screened was statistically significantly higher for women who had been pregnant previously than for women pregnant for the first time (4.8% v. 1.4%; p < 0.001). Of the 200 women who were seronegative at the time of screening (8.4%), 79 had been vaccinated postpartum, had a positive serological result on subsequent testing or did not require vaccination, and 59 had not been vaccinated postpartum; for 62, subsequent vaccination status was unknown. INTERPRETATION: Continued improvement in screening practices is needed, especially in small hospitals. Because vaccination rates are unacceptably low, it is crucial that steps be taken to address this issue.     

Rubella antibody titres and immunization status in a family practice.

Rubella vaccination status and immunity to rubella were studied in 230 "active patients" aged 8 to 22 years in a teaching family practice by means of a chart review and measurement of the rubella antibody titre in a blood sample. Of the 200 patients who submitted a blood sample 161 (80%) were found to be immune, having a rubella hemagglutination-inhibiting antibody titre of 1:16 or greater. Log linear analysis showed that immunity to rubella was independent of a history of rubella, and that 94% of the vaccinated patients versus 74% of the unvaccinated patients (a significant difference; P = 0.007) were immune. In retrospect we estimated that 80% of the study group were protected at the start of the study. After surveillance and follow-up, with vaccination of 27 of the 39 patients identified as susceptible to rubella, this estimated proportion increased to 90%. The study showed that there is nothing to be gained by asking about a history of rubella but that vaccination against this disease is increasing among children aged 5 to 9 years.     

健康人群风疹抗体水平监测及风疹疫苗免疫效果观察

目的 了解人群风疹免疫状况及国产风疹疫苗的免疫效果，为风疹疫苗的科学使用提供依据。方法 采用酶联免疫吸附试验(ELISA)，检测本区不同年龄健康人群的风疹特异性抗体IgG的水平，以及1周岁左右无风疹免疫史的儿童用国产风疹疫苗免疫前后的IgG水平。结果 一般人群风疹IgG抗体的阳性率为68．84％，孕妇风疹IgG抗体阴性率为23．17％，国产风疹疫苗免疫成功率为96．13％。结论 低龄儿童和青少年风疹免疫水平较低，是风疹疫苗接种的主要对象，国产风疹疫苗具有良好的免疫原性，可产生较好的免疫效果。     

妊娠合并慢性乙型肝炎病毒感染（CHB）对新生儿生长发育的影响

 目的  探讨妊娠合并慢性乙型肝炎病毒感染(chronic hepatitis B virus infection,CHB)对新生儿生长发育的影响。方法  采用前瞻性研究设计,纳入 2012年6月1日至2013年3月15日在安徽省安庆市立医院住院分娩的孕妇为研究对象,收集血清标本并进行乙型肝炎病毒表面抗原(hepatitis B surface antigen,HBsAg)的酶联免疫吸附法筛检并经电化学发光法确证,通过医院电子病历系统收集孕妇人口学信息和新生儿的生长发育指标,并通过单因素和多因素分析方法分析妊娠合并CHB与新生儿生长发育指标的关系。结果  在1 159例孕产妇中,单胎活产为1 028例,其中妊娠合并CHB组与非CHB组分别为72例和956例,两组在人口学特征方面相似可比,两组的体质指数、孕次、产次等方面差异均无统计学意义。单因素和多因素分析均显示两组间在胎龄、孕周、新生儿身长、出生体重、Apgar评分、性别及剖宫产比例的差异均无统计学意义。结论  本研究并未发现妊娠合并CHB影响新生儿的生长发育。