Effect of rubella vaccination programme in schools on rubella immunity in a general practice population.

Between November 1979 and January 1980 all patients aged 13-21 years who attended a general practice in Glasgow were tested for their immunity against rubella (single radial haemolysis test). All of the women in the sample should have been vaccinated at 13 as part of the rubella vaccination programme, which began in Glasgow in 1971. The programme excludes boys. Of the 77 females and 64 male patients studied, nine (11.7%) and 10 (15.6%), respectively, were susceptible to the infection. For only 34 women was evidence of vaccination documented in the practice records, and three of those either had failed to seroconvert or had antibody below detectable values. Overall there was no significant differences between the proportion of men and women who were susceptible to the disease. The rubella vaccination programme had clearly failed to reduce the number of susceptible women in this practice. Hence the immune state of all girls should be checked at about 15 years of age, so that as many as possible may be rendered immune before they leave school.     

Rubella screening and immunisation of schoolgirls: results six to seven years after vaccination.

A long term follow-up study was carried out of girls given RA27/3 or Cendehill rubella vaccine in their 13th-14th year compared with a group of girls who had been found to be naturally immune at the age. A high proportion of the girls in all groups had persistent rubella antibody six to seven years after inclusion in the study, although some of these would have been considered to be susceptible to rubella by methods currently in use for screening for rubella antibody. Great care should be taken in interpreting the efficiency of the schoolgirl immunisation policy in the United Kingdom; women in their childbearing years who may have received vaccine but are found by a screening test to be seronegative should be retested by a more sensitive procedure before a final report is made.     

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.     

Clinical and Serological Assessment of Children Exposed in Utero to Confirmed Maternal Rubella

As a result of the work of the Public Health Laboratory Service Working Party on Rubella (1970) it was possible to examine the children of 60 susceptible women who were in contact with rubella during their pregnancy and who subsequently showed serological evidence of the infection, despite immunoglobulin prophylaxis. When the children were assessed between 8 months and 4 years 8 months of age a blood sample was also taken and tested for rubella antibodies so that a retrospective diagnosis of congenital rubella infection could be made. Only 19% of children exposed to subclinical maternal rubella showed evidence of intrauterine infection compared with 53% of those born to mothers who had clinical rubella. One of the 26 children exposed to subclinical maternal infection had a rubella defect, compared with 9 of the 34 children exposed to clinical maternal rubella.     

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.     

Rubella Vaccination and Termination of Pregnancy

Six terminations of pregnancy have been carried out in Leicestershire since February 1970 because of rubella vaccine administered inadvertently during early unrecognized pregnancy. Any woman of child bearing age shown by serological tests to be susceptible to rubella should be offered vaccination, preceded and followed by adequate contraception.     

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.     

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.     

Stability of rubella complement-fixing antigens

Various types of rubella complement-fixing (CF) antigen preparations derived from infected BHK-21 cell cultures were examined for stability to certain chemical and physical agents. Antigens studied included: infected culture fluids concentrated 100-fold, ether-treated fluid concentrates, alkaline buffer extracts of infected cells, and large- and small-particle CF antigens separated by Sephadex gel filtration. All preparations were stable at -20 C for months, and were unaffected by three cycles of freezing and thawing. Ether treatment rendered antigens highly susceptible to thermal inactivation at 56 C; untreated antigens were inactivated slowly and showed a persistent fraction of activity even after 2 hr. Large-particle antigen was found to be slightly more susceptible than small-particle antigen to thermal inactivation and ether treatment. CF activity in alkaline buffer extracts was more labile than that in untreated or ether-treated fluid concentrates upon dialysis, Sephadex gel filtration, and sucrose density gradient centrifugation.     

Role of the occupational health service in screening and increasing the uptake of rubella immunisation.

An occupational health department in a district general hospital in Newcastle upon Tyne screened 487 women of childbearing age for rubella immunity who were prospective employees and whose immunity state was unknown. Ninety per cent of these women were immune. Of the 51 who were found to be susceptible, 29 accepted vaccination.     

Prevention of congenital rubella.

The vaccine of choice for rubella vaccination is considered to be RA 27/3, based on frequency of side effects, duration of immunity, antigenic potential and rate of reinfection by wild virus. The most appropriate individuals to be vaccinated are prepubertal schoolgirls and susceptible members of other high-risk groups, and a nationwide immunization program is suggested. Premarital determination of rubella-immune status should be mandatory for all women of childbearing age. A favourable cost/benefit ratio for rubella vaccination seems highly probable. The use of a rubella "fact sheet" to provide education and information for those at risk is strongly recommended.     

Imported Genotype 2B Rubella Virus Caused the 2012 Outbreak in Anqing City,China

A rubella outbreak occurred in Anqing city of Anhui province, China, from February to July of 2012, and a total of 241 clinically diagnosed or lab-confirmed patients were reported. The highest number of rubella cases during this outbreak was recorded in teenagers between 10 and 19 years of age who had not previously received the rubella vaccine. Genotyping results indicated that the genotype 2B rubella virus (RV) was responsible for the outbreak. However, a phylogenetic analysis showed that the genotype 2B RVs isolated in Anqing City were not related to 2B RVs found in other cities of Anhui province and in other provinces of China, thus providing evidence for importation. After importation, the transmission of Anqing RVs was interrupted owing to an effective immunization campaign against rubella, suggesting the timeliness and effectiveness of contingency vaccination. Strengthening rubella surveillance, including the integration of epidemiologic information and laboratory data, is a vital strategy for rubella control and elimination. In addition, except for routine immunization, targeted supplementary immunization activities aimed at susceptible groups according to sero-epidemiological surveillance data also play a key role in stopping the continuous transmission of rubella viruses and in preventing further congenital rubella syndrome cases.     

Defectiveness of Interferon Production and of Rubella Virus Interference in a Line of African Green Monkey Kidney Cells (Vero)

Vero cells, a line of African green monkey kidney cells, failed to produce interferon when infected with Newcastle disease, Sendai, Sindbis, and rubella viruses, although the cells were sensitive to interferon. Further, infection of Vero cells with rubella virus did not result in interference with the replication of echovirus 11, Newcastle disease virus, or vesicular stomatitis virus, even in cultures where virtually every cell was infected with rubella virus. Under the same conditions, BSC-1 cells and other cells of primate origin produced interferon and showed rubella virus interference. The results indicate that the presence of rubella virus in the cell does not in itself exclude multiplication of other viruses and that rubella virus interference appears to be linked to the capability of the cell to produce interferon.     

Vaccination campaigns for common childhood diseases

Mathematical models exist for vaccination programs for common childhood diseases such as measles, chickenpox, polio, rubella, and mumps. In compartmental models, the population is divided into compartments containing susceptible, infected, and immune individuals, and the model also takes account of the age structure in the population. An equilibrium analysis is performed on the resulting partial differential equations to determine the vaccination program that just eliminates the disease. The stability of the resulting equilibrium solutions is also examined. Particular attention is paid to multistage vaccination strategies that vaccinate given proportions of susceptible individuals at various ages. Finally, some numerical results are analyzed to see what these vaccination coverages mean for certain common childhood diseases.     

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.     

2012年广州市越秀区疑似麻疹风疹病例血清学检测结果分析

目的:对2012年广州市越秀区疑似麻疹风疹的血清学结果进行整理分析,以了解麻疹风疹病例的流行特点。方法:选取2012年1月-2012年12月的166例疑似麻疹风疹患者的血清作为研究对象,统计血清中IgM阳性抗体的检出情况,以及各年龄段、月份IgM抗体阳性的例数及构成比。结果:麻疹风疹疑似病例中有36.1%的患者检测出IgM抗体阳性,其中麻疹IgM阳性以0-1岁婴幼儿的检出率较高,可达44.4%。从月份来看,12月、8月和5月是麻疹的好发时期。风疹IgM阳性以20岁以上中老年患者检出率最高,为75.0%,7月、4月和5月是风疹的易感季节。结论:疑似麻疹风疹病例有较高的IgM抗体阳性检出率,0-1岁婴幼儿和20岁以上中老年人是麻疹风疹的易感人群,4-5、7-8和12月是发病的高峰时期,临床应注意加强防范。     

应用ELISA法检测风疹病毒IgG抗体

实验证明,将0.1％脱氧胆酸钠制备的风疹病毒粗制抗原,用于ELISA法检测风疹病毒IgG抗体,效果较满意,方法的特异性好,与常规血凝抑制试验(HI)的相关性也好,所测抗体的几何平均值为HI的4倍。用本法初步调查了北京市不同年龄人群的风疹感染率,证明随年龄增长风疹感染率迅速上升,18岁以上人群达94％。检测河北省沧州地区孕妇的风疹IgG阳性率为99％。用於风疹病人的血清学诊断,获得较好结果。     

Congenital Perceptive Deafness: Role of Intrauterine Rubella

Rubella antibody was detected in 85 (61%) of 139 children aged from 6 months to 7 years with congenital perceptive deafness. Of the 112 children who were aged under 4 years 61 (54%) had rubella antibody (seropositive) compared with 7·1% in randomly selected children of the same age. A close correlation was found between the presence of antibody in children with perceptive deafness and (1) a maternal history of rash or contact in early pregnancy, and (2) with the presence of other rubella-type defects. Intrauterine rubella was thought to be the cause of the deafness in 82 (59%) of the 139 children, in 60 of whom deafness was the only rubella defect detected. Thus intrauterine rubella should be considered a likely cause of congenital perceptive deafness in a child under 4 years in whom rubella antibody is present.     

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.     

A Plaque Method for Rubella Virus Assay

A method has been described in which suitable dilutions of rubella virus will induce the formation, in a monolayer of green monkey kidney cells, of islets of infected cells which were protected from the effects of Echo 11 challenge virus. The number of islets or “negative” plaques was proportional to the dilution of rubella virus inoculated on to the monolayer. Using this method, it was observed that bentonite adsorption increased the plaque assay values of rubella virus pools. This suggested that rubella virus interference may be mediated by an interferon-like principle.