Simulations of rubella vaccination strategies in China

Many infants whose mothers have rubella infections during their first trimester of pregnancy have birth defects called congenital rubella syndrome (CRS). China does not routinely vaccinate against rubella in the public sector, but may need to start as its 'one child per couple' policy changes the population age distribution and the dynamics of rubella epidemiology, so that the incidence of rubella in pregnant women increases. Computer simulations with demographic transitions and rubella transmission dynamics predict that, with no or limited rubella vaccination, CRS incidence in China in the 30 years after 2020 will be more than twice the level in 2005. Comparisons of rubella vaccination strategies using computer simulations show that routine vaccination of over 80% of 1-year-old children would be effective in reducing total CRS cases in 2005-2051 and eliminating rubella in China by 2051. Routine immunizations at higher levels and the addition of early mass vaccinations of 2-14-year-old children and women of childbearing ages would further reduce total CRS cases and speed up the elimination of rubella.     

Seroprevalence of Cytomegalovirus,Epstein Barr Virus and Varicella Zoster Virus among Pregnant Women in Bradford: A Cohort Study

Objective

To estimate the seroprevalence of cytomegalovirus (CMV), Epstein Barr virus (EBV) and varicella zoster virus (VZV) among pregnant women in Bradford by ethnic group and country of birth.

Methods

A stratified random sample of 949 pregnant women enrolled in the Born in Bradford birth cohort was selected to ensure sufficient numbers of White UK born women, Asian UK born women and Asian women born in Asia. Serum samples taken at 24-28 weeks’ gestation were tested for CMV IgG, EBV IgG and VZV IgG. Each woman completed a questionnaire which included socio-demographic information.

Results

CMV seroprevalence was 49% among the White British women, 89% among South Asian UK born women and 98% among South Asian women born in South Asia. These differences remained after adjusting for socio-demographic factors. In contrast, VZV seroprevalence was 95% among women born in the UK but significantly lower at 90% among South Asian women born in Asia. EBV seroprevalence was 94% overall and did not vary by ethnic group/country of birth.

Conclusions

Although about half of White British women are at risk of primary CMV infection in pregnancy and the associated increased risk of congenital infection, most congenital CMV infections are likely to be in children born to South Asian women with non-primary infection during pregnancy. South Asian women born in South Asia are at risk of VZV infection during pregnancy which could produce congenital varicella syndrome or perinatal chickenpox. Differences in CMV and VZV seroprevalence by ethnic group and country of birth must be taken into account when universal immunisation against these viruses is contemplated.     

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.     

Surveillance of antibody to rubella virus in Grampian: closing the immunity gap.

OBJECTIVES--To identify causes for the continuing deficit of rubella immunity in women of childbearing age with a view to further reducing the risk of the congenital rubella syndrome. DESIGN--A questionnaire was sent to the general practitioner and a laboratory follow up study conducted in a one year cohort of women found on screening to have inadequate protection against rubella. SETTING--Virus laboratory of the department of medical microbiology, Aberdeen, serving the health board areas of Grampian, Orkney, and Shetland. PATIENTS--239 women whose concentration of antibodies to rubella virus was either absent or below standard (15,000 IU/l) and whose general practitioner could be contacted to supply a history of infection, immunisation, pregnancy, and antibody testing. MAIN OUTCOME MEASURES--Whether rubella vaccination was given and whether those vaccinated were tested for seroconversion. RESULTS--Only 122 (55%) of the women for whom information was available received the recommended vaccine; only 74 (61%) of these were tested for seroconversion. Oversight was the reason given for not vaccinating 64 (65%) of the women who remained at risk. Women who were pregnant when tested were significantly less likely to receive vaccine (odds ratio 3.36) than women who were not pregnant, and even if vaccinated were less likely to have a follow up antibody test (odds ratio 1.94). CONCLUSION--Once women are identified as being unprotected against rubella they are often overlooked and not vaccinated. Prompting mechanisms aimed at general practitioners, such as the one recently set up in Grampian, should reduce the immunity gap and help to eradicate rubella in pregnancy.     

Increase in congenital rubella occurrence after immunisation in Greece: retrospective survey and systematic review

ObjectiveTo describe the events leading to the epidemic of congenital rubella syndrome in Greece in 1993 after a major rubella epidemic.DesignRetrospective survey and systematic review.SettingGreece (population 10 million), 1950-95.SubjectsChildren, adolescents, and women of childbearing age.ResultsAround 1975 in Greece the measles, mumps, and rubella vaccine started being given to boys and girls aged 1 year without policies to attain high vaccination coverage and to protect adolescents and young women. During the 1980s, vaccination coverage for rubella remained consistently below 50%, and the proportion of pregnant women susceptible to rubella gradually increased. In 1993 the incidence of rubella in young adults was higher than in any previous epidemic year. The epidemic of congenital rubella that followed, with 25 serologically confirmed cases (24.6 per 100 000 live births), was probably the largest such epidemic in Greece after 1950.ConclusionsWith low vaccination coverage, the immunisation of boys and girls aged 1 year against rubella carries the theoretical risk of increasing the occurrence of congenital rubella. This phenomenon, which has not been previously reported, occurred in Greece.     

Pregnant Women in and Around Dhaka City: Are Their Children at Risk of Developing Congenital Rubella Syndrome?

Rubella Virus (RUBV) is a common cause of childhood rash and fever in non-immunized populations, and its public health importance relates to teratogenic effects of primary rubella infection in women with early pregnancy. Infection of the fetus may lead to congenital rubella syndrome (CRS). This work aimed to assess the degree of risk associated in acquiring rubella virus infection by the women during pregnancy and developing CRS among their children in Bangladesh. The study population (n = 275) included pregnant mothers (15–38 years) from various socioeconomic backgrounds attending a women health care based hospital. All subjects were personally interviewed, clinically examined and a standardized questionnaire was filled up for each of them. From each participant 3 ml blood was taken and serum was separated. Commercially available ELISA kit was used for the qualitative and quantitative determination of IgM and IgG class antibodies against RUBV in collected serum samples. 209 women were found to contain detectable level of antiRUBV IgG antibodies, but did not possess IgM antibodies against rubella. Only 9% participants were vaccinated previously against rubella virus among the whole antenatal population studied. Ninety-two percent of these vaccinated pregnant women contained serum anti-rubella IgG antibody which was significantly (P = 0.05) higher than that of the nonvaccinated study population (75%). Pregnant women from lower middle and poor socioeconomic class had significantly (P = 0.05) more intra uterine growth retardation (IUGR) of fetus than the upper middle class. 20% of the women of child bearing age examined in this work were not yet exposed to RUBV and at risk of acquiring this virus during pregnancy and subsequently transmitting the virus to the fetus. Our work demonstrates rubella attack rate among antenatal population in Bangladesh as 14.5 in 1000 during pregnancy. A proper and reliable vaccination policy against rubella virus is not yet adopted at the national level in many developing countries including Bangladesh. This work identifies the requirement of detailed study for the identification of intrauterine rubella infection and its related influence on perinatal morbidity and mortality. Thorough epidemiological studies are also considered necessary prior to the development and acceptance of national immunization program against rubella virus in Bangladesh.     

3670 例早期妊娠妇女梅毒血清学检查及处理

目的:了解早期妊娠妇女梅毒感染情况,采取防治措施,减少先天梅毒的发生。方法:采用梅毒明胶颗粒试验(TPPA)和梅毒甲苯胺红试验(TRUST)对早期妊娠妇女进行梅毒血清学检查,两项结果均阳性者诊为妊娠期梅毒,可采取驱梅治疗或终止妊娠。结果:3670例早期妊娠妇女中,确诊为妊娠期梅毒的29例,其中TRUST滴度大于1:8的有8例,小于1:8的有21例;有12人接受驱梅治疗,有17人选择终止妊娠。结论:在早期妊娠妇女中进行梅毒血清学检查,可及早采取措施,减少先天梅毒的发生。     

三江地区妊娠妇女风疹病毒感染的血清学分析

目的调查2005年三江地区妊娠妇女风疹病毒感染情况。方法收集400例妊娠8～24周孕妇血清,采用酶联免疫吸附法（ELISA）检测风疹特异性IgM抗体,对IgM阳性患者进一步用PCR检测风疹病毒RNA,对该人群的风疹病毒感染率进行调查。结果检测400例孕妇风疹病毒IgM,阳性20例,阳性率为5．00％;检测IgM阳性者的风疹病毒RNA,结果阳性8例,占IgM阳性者的40．00％。结论用ELISA和PCR法进行妊娠早期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。     

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.     

妊娠合并甲状腺功能减退症26例妊娠结局分析

目的：对妊娠合并甲状腺功能减退症进行分析,探讨其对母儿的影响,及孕期筛查甲状腺功能有无意义。方法：对我院26例妊娠合并甲减的临床资料进行回顾性统计分析。结果：26例妊娠合并甲减病例中有1例早产（孕33周）,其余25例患者维持至足月妊娠,其中剖宫产17例（65.38%）,合并妊娠期高血压疾病5例（19.23%）,妊娠期糖尿病3例（11.53%）,羊水胎粪污染3例（11.54%）,新生儿无先天性甲减。经过治疗后甲状腺功能减退孕妇的剖宫产率,糖尿病发生率、高血压疾病发生率、羊水粪染的发生率较对照组增加;但两组妊娠结局差异无统计学意义（P〉0.05）。结论：妊娠合并甲状腺功能减退症孕妇多种妊娠并发症的发病率高于正常孕妇,应加强对妊娠甲减的早期筛查及治疗,可有效降低不良妊娠结局,减少先天性甲低的出生。     

Predictors of ratio of placental weight to fetal weight in multiethnic community.

OBJECTIVE--To determine whether placental ratio is influenced by maternal ethnic origin, obesity, hypertension, and haematological indices of iron deficiency anaemia. DESIGN--Observational study. SETTING--District general hospital in Birmingham. SUBJECTS--692 healthy nulliparous pregnant women, of whom 367 were European, 213 Asian, 99 Afro-Caribbean, and 13 of other or undocumented ethnic origin. MAIN OUTCOME MEASURES--Placental ratio and maternal body mass index, blood pressure, and haematological indices. RESULTS--Though birth weight and placental weight were lower in Asian women than in other groups, mean placental ratio was similar in Asian (19.5% (SD 3.3%)), European (20.0% (4.0%)), and Afro-Caribbean women (20.4% (5.3%)). Gestational age at birth was the main predictor of placental ratio in the univariate analysis (r = -0.34, P < 0.001) and multivariate analysis. The only other significant predictor of placental ratio in multivariate analysis was maternal body mass index, which was positively associated with placental ratio (r = 0.1, P = 0.01). Mean (SD) placental ratio was not significantly higher in women who developed gestational hypertension (20.4% (4.5%)) and pre-eclampsia (23.3% (7.3%)) than in normal women (19.8% (3.8%)). No evidence of a relation between placental ratio and first antenatal visit haemoglobin concentration or mean cell volume was detected, and placental ratio was not associated with change in mean cell volume during pregnancy or with third trimester serum ferritin concentration. CONCLUSIONS--These data do not support the proposed association between poor maternal nutrition and increased placental ratio. The association between high placental ratio and adult hypertension may be confounded by genetic and environmental factors associated with maternal obesity (and possibly maternal hypertension).     

Comparative sero-epidemiologic observations of rubella infection in pregnant women and female university students

Sera from 58 pregnant women and 34 female university students were tested by a haemagglutination-inhibition (HI) method to determine the levels of immunity to rubella and to assess factors important in its epidemiology. Ages of women ranged from 15 to 35 years. Pregnant women were from the lower socio-economic groups, whilst students came from middle and upper income families. In both groups immunity to rubella increased with age. Students were more susceptible to the infection than pregnant women (21% compared with 3% respectively) - p less than 0.05 and the geometric mean titre was significantly higher in pregnant women than in students. Since women were of the same ages and essentially from the same geographical location, it is suggested that differences in susceptibility rates to rubella were due to differences in the socio-economic status of the two groups.     

The Need for Routine Rubella Antibody Testing of Women

Results of rubella antibody tests performed by the California State Viral and Rickettsial Disease Laboratory on blood specimens collected in 1968 and 1969 from school children and women of childbearing age showed a slightly lower prevalence of rubella antibody in California than reported from most other areas of the United States. Among women of childbearing age, rubella hemagglutination-inhibition (hi) antibody was found in 72 percent of those tested in California compared with 80 percent to 90 percent in other areas of the country.Rubella antibody testing services offered by the State Virus Laboratory included situations in which a pregnant woman was exposed to a suspected case of rubella. It was shown that very few of these exposures constitute a significant risk to the fetus as most of the women already possessed antibody to rubella from past infection and in many instances the exposures were not to actual cases of rubella.The results of this study emphasized the urgency of obtaining blood specimens from pregnant women as soon as possible after exposure to rubella or development of symptoms of rubella. The urgency and anxiety attending these situations can largely be obviated if routine rubella antibody testing of women is carried out prior to pregnancy or at the first prenatal visit.     

Increase in urinary thromboxane excretion during pregnancy and labor

Urinary TXB2 excretion was measured during pregnancy and labor using high pressure liquid chromatography and radioimmunoassay. From the first trimester onwards TXB2 levels in urine of pregnant women (n = 60) were significantly (p less than 0.001) higher than in non-pregnant women (n = 12) and they increased, albeit not significantly, with advancing gestation. Labor was associated with a two-fold increase in urinary TXB2 excretion. Levels in established labor were significantly higher than at any other time in pregnancy (p less than 0.001), but the levels in incipient labor showed considerable overlap with these in late pregnancy. Thus urinary TXB2, while not necessarily originating from the pregnant uterus, appears to reflect the uterine activity of labor and may be the expression of a general stimulation of prostanoid production during parturition.     

Letter: Spontaneous pelvic thrombosis in the postmenopausal woman.

An epidemic of rubella reached its peak in the Atlantic provinces in 1974, subsiding in early 1975. With the exception of Quebec the remainder of Canada showed a reverse trend, with a large increase in the numbers of cases reported in the first 41/2 months of 1975. The Halifax virus laboratory reported 106 serologically proven cases of rubella in 1974, 44 of them in pregnant women. In the aftermath of the epidemic many infants were born with the congenital rubella syndrome (CRS). A study carried out from Sept. 1, 1974 through Apr. 30, 1975 showed an 80% correlation between clinical diagnosis and the presence of rubella-specific IgM antibodies in 35 of these infants. Of the 23 infants in whom the diagnosis of CRS was made by laboratory or clinical findings or both, laboratory criteria were met in 20 (87.0%), clinical criteria in 19 (82.6%) and both laboratory and clinical criteria in 16 (69.6%).     

Rubella Epidemic in a Maternity Unit

Four cases of rubella, the last confirmed by laboratory tests, occurred among the nurses of a large obstetric unit. Immediate measures were taken to prevent the spread of the infection to pregnant patients and staff, and none was in fact infected.Persons susceptible to rubella and who become infected may pose a real danger to women in early stages of gestation during the incubation period. We recommend that the immune status of medical and nursing personnel working in obstetric departments should be ascertained serologically, and that rubella vaccine should be offered to those who are susceptible.     

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.     

Immunity to rubella in women of childbearing age in the United Kingdom.

In the first three years of a surveillance scheme for susceptibility to rubella in women aged 15-44 the results of over 1.3 million serological tests were collected by 80 laboratories throughout the United Kingdom. Seventy eight per cent of the results, or an average of 340,000 a year, were from pregnant women, so that just under half of all pregnant women in the United Kingdom were reported on. Eighteen per cent of results were from women tested before vaccination and the remainder were from diagnostic and other tests. Pregnant women showed an overall downward trend in susceptibility to rubella (from 4.2% at the beginning of 1984 to 3.0% at the end of 1986), and a similar decline was seen in the two other categories. Regional data showed a significant negative correlation between the proportion of pregnant women aged 15-19 who were susceptible to the virus and rate of uptake of vaccine in 14 year old schoolgirls. Women aged 25-29 were least susceptible. This form of laboratory surveillance is feasible and representative; it should be continued to monitor the effect of introducing the measles, mumps, and rubella vaccine.     

Erythema infectiosum and pregnancy-related complications.

Erythema infectiosum, an acute, communicable viral disease with a highly distinctive exanthem, follows the usual course of a self-limiting benign disease. In pregnant women, however, it may be associated with fetal death and nonimmune hydrops fetalis. Because of the association of human parvovirus (HPV) B19 infection with fetal damage we reviewed the current knowledge of the clinical aspects of erythema infectiosum, focusing on pregnancy and fetal outcome, to determine the magnitude of fetal risk and offer recommendations for management. Among 180 infected pregnant women 44 fetal deaths (24%) occurred, 1 to 12 weeks after the infection was noted. Pregnant women should be advised that (a) because of the high prevalence (up to 65%) of anti-HPV B19 IgG antibody among adults most of them are not at risk and (b) if maternal infection does occur therapeutic abortion is not indicated since intrauterine infection causes fetal death more often than abnormal development. Infection should be suspected in pregnant women who exhibit the symptoms of erythema infectiosum with or without arthropathy. They should be monitored for an elevated serum alpha-fetoprotein level (indicating fetal aplastic crisis) and undergo serial ultrasonography for the detection of hydrops fetalis. Although the incidence of congenital malformation is no higher than the expected rate in the general population (3% to 5%), the precise incidence of fetal adverse outcomes remains unknown and requires investigation in larger, prospective studies.     

Evaluation of the incidence of congenital rubella in GDR]

Annual number of congenital rubellas in GDR was evaluated by means of a mathematic model. Dates of inmunity rate of rubella in L. and P. districts obtained by means of haemagglutination inhibition reaction were taken into account. From these dates of a number of possible primary cases of rubella infection in wifes in the first 3 months of pregnancy as well as literary dates on mean number of monsters determined after the infection, i.e. 10--15--25% cases, were evaluated. There were obtained in relation with different mean numbers of monsters 37--56--93 cases of congenital rubellas for live born children from mothers at the age of 14 to 45 years. It results in total that the incidence of disease for live born children from mothers up to 45 years, is 0,2--0,5%, i.e. 2--5 children with congenital rubella on 10 000 live born children. Compared with literary data, it results a good correlation between proper evaluations and numbers of congenital rubella incidence quoted by other authors. In view of these evaluations, a conclusion to introduce protective rubella vaccination, is fully justified.