Comparison of rubella seroepidemiology in 17 countries: progress towards international disease control targets

OBJECTIVE: To standardize serological surveillance to compare rubella susceptibility in Australia and 16 European countries, and measure progress towards international disease-control targets. METHODS: Between 1996 and 2004, representative serum banks were established in 17 countries by collecting residual sera or community sampling. Serum banks were tested in each country and assay results were standardized. With a questionnaire, we collected information on current and past rubella vaccination programmes in each country. The percentage of seronegative (< 4 IU/ml) children (2-14 years of age) was used to evaluate rubella susceptibility, and countries were classified by seronegativity as group I (< 5%), group II (5-10%) or group III (> 10%). The proportion of women of childbearing age without rubella protection (< or = 10 IU/ml) was calculated and compared with WHO targets of < 5%. FINDINGS: Only Romania had no rubella immunization programme at the time of the survey; the remaining countries had a two-dose childhood schedule using the measles, mumps and rubella (MMR) vaccine. The percentage of susceptible children defined five countries as group I, seven as group II and four as group III. Women of childbearing age without rubella protection were < 5% in only five countries. CONCLUSION: Despite the low reported incidence in many countries, strengthening the coverage of the routine two-dose of MMR vaccine among children is needed, especially in group III countries. Catch-up campaigns in older age groups and selective targeting of older females are needed in many countries to ensure necessary levels of protective immunity among women of childbearing age.     

Modelling rubella in Europe

The prevention of congenital rubella syndrome (CRS), as a complication of rubella infection during pregnancy, is the main aim of rubella vaccination programmes. However, as vaccination of infants leads to an increase in the average age at which those who were not immunized become infected, certain rubella vaccination programmes can lead to an increase in the incidence of CRS. In this paper we use a mathematical model of the transmission dynamics of rubella virus to investigate the likely impact of different vaccination policies in Europe. The model was able to capture pre- and post-vaccination patterns of infection and prevalence of serological markers under a wide variety of scenarios, suggesting that the model structure and parameter estimates were appropriate. Analytical and numerical results suggest that endemic circulation of rubella is unlikely in Finland, the United Kingdom, The Netherlands, and perhaps Denmark, provided vaccine coverage is uniform across geographical and social groups. In Italy and Germany vaccine coverage in infancy has not been sufficient to interrupt rubella transmission, and continued epidemics of CRS seem probable. It seems unlikely that the immunization programmes in these countries are doing more harm than good, but this may be partly as a result of selective immunization of schoolgirls. Indeed, in both these countries, selective vaccination of schoolgirls with inadequate vaccination histories is likely to be an important mechanism by which CRS incidence is suppressed (unlike the other countries, which have had sufficiently high infant coverage rates to withdraw this option). Reducing inequalities in the uptake of rubella vaccine may bring greater health benefits than increasing the mean level of coverage.     

Policies for immunization against rubella in European countries

In 1986 a survey on immunization policies against rubella was conducted in 17 European countries. A questionnaire was sent to each Ministry of Health and selected practitioners, requesting information on official policy for vaccination against rubella, level of policy decision, immunization strategy, target groups, current recommendations for vaccination, measures taken to facilitate vaccine uptake, vaccine strains used and legislation concerning abortion.A policy for the prevention of congenital rubella is explicitly defined in 16 countries (in 12 at a national level, in 3 at a regional level and in one at both levels). In Greece only, no official policy has been defined, although the practice is to vaccinate infants over 15 months of age and girls by 9–11 years of age. There are 3 countries maintaining the selective strategy of vaccinating teenage girls, but in 8 countries this strategy changed to a mass vaccination of young infants. In 5 other countries an approach combining both mass immunization and selective vaccination is adopted. This situation of different strategies between countries in Europe could have a deleterious effect for young migrants or travelling pregnant women and could reduce the effectiveness of programmes for prevention of congenital rubella syndrome. Harmonization of immunization policies and of recommendations for vaccine administration is advisable. The mass vaccination of all young children combined with systematic revaccination either of all children or of teenage girls is probably the most effective approach for elimination of congenital rubella syndrome in Europe.Corresponding author.     

Rubella and congenital rubella syndrome: global update.

Worldwide, it is estimated that there are more than 100.000 infants born with congenital rubella syndrome (CRS) each year. In 1998, standard case definitions for surveillance of CRS and rubella were developed by the World Health Organization (WHO). In 2001, 123 countries/territories reported a total of 836.356 rubella cases. In the future more countries are expected to report on rubella as a global measles/rubella laboratory network is further developed under the coordination of WHO. Operational research is being conducted to improve rubella surveillance. This includes projects on initiating CRS surveillance, comparative studies on diagnostic laboratory methods, and molecular epidemiology research to expand the global understanding of patterns of rubella virus circulation. In 1996 a WHO survey found that 78 od 214 reporting countries/territories (36%) were using rubella vaccine in their routine immunization services. By the en of 2002 a total of 124 of the 214 counties/territories (58%) were using rubella vaccine. Rubella vaccine use varies by stage of economic development: 100% for industrialized countries, 71% for countries with economies in transition, and 48% for developing countries. A safe effective rubella vaccine is available, and there are proven vaccination strategies for preventing rubella and CRS. A WHO position paper provides guidance on programmatic aspects of rubella vaccine introduction. The introduction of rubella vaccine is cost-effective and cost-beneficial but requires ongoing strengthening of routine immunization services and surveillance systems.     

Modelling the incidence of congenital rubella syndrome in developing countries

BACKGROUND: As of 1997, less than one-third of developing countries included rubella vaccine in their national immunization programme. In countries that have achieved high coverage of measles vaccine, an ideal opportunity exists to include control of rubella and congenital rubella syndrome (CRS) in enhanced measles control activities. Data on the burden of congenital rubella syndrome are important to guide rubella vaccination policies. METHODS: We reviewed the literature to identify studies of rubella antibody prevalence in developing countries that were conducted on populations with no major selection bias, prior to wide-scale rubella vaccination in the country. We used a simple catalytic model to describe the age-specific prevalence of susceptibility to rubella virus infection in given populations. Estimates of the incidence of infection among pregnant women were calculated using expressions for the average prevalence of susceptibility to infection and the incidence of infection during gestation. To estimate the number of cases of CRS, we assumed an overall risk of 65% after infection in the first 16 weeks of pregnancy and zero risk thereafter. These estimates were derived for each country for which data were available, then for each World Health Organization region, excluding Europe. RESULTS: The estimated mean incidence of CRS per 100,000 live births was lowest in the Eastern Mediterranean region (77.4, range 0-212) and highest in the Americas (175, range 0-598). The mean of the estimates of the total number of cases of CRS in developing countries in 1996 was approximately 110,000. The range was, however, very wide, from as few as 14,000 to as many as 308,000 cases. CONCLUSIONS: Congenital rubella syndrome is an under-recognized public health problem in many developing countries. There is an urgent need for collection of appropriate data to estimate the cost-effectiveness of a potential global rubella control programme.     

山东省实施儿童风疹疫苗免疫后风疹发病年龄变化趋势的分析

目的分析山东省自1995年开始实施儿童风疹疫苗免疫后风疹发病年龄的变化趋势。方法对1999—2004年通过麻疹疫情专报系统得到的风疹疫情资料以及风疹疫苗接种情况进行分析。结果1999—2004年山东省风疹年平均报告发病率为0．59／10万，多为暴发（占总病例数的81．17％）；发病主要集中在7～15岁学龄儿童（77．77％），7岁以下发病较少（占7．93％），发病年龄中位数分别为10．37岁、11．66岁、11．41岁、12．81岁、14．28岁和13．96岁，发病高峰年龄逐年后移，成人发病有所增加；学龄前儿童风疹疫苗基础免疫估算接种率约为60％，学龄儿童约为20％。结论风疹发病年龄后移，将威胁育龄期妇女，增加发生先天性风疹综合征的危险性；应在继续做好儿童风疹免疫的同时，积极开展育龄期妇女风疹抗体筛查及疫苗接种工作。     

Prevalence of antibodies against rubella virus in The Netherlands 9 years after changing from selective to mass vaccination

A two-dose mass vaccination programme with a combined vaccine against measles, mumps and rubella (MMR) was adopted in the Netherlands in 1987, replacing the selective schoolgirl vaccination strategy introduced in 1974. To obtain insight into the effect of mass vaccination and the population's immunity, the antibody levels against rubella were studied in the general Dutch population and in religious groups refusing vaccination. In the national sample, we observed a high prevalence (96.5%) for rubella antibodies in vaccinated cohorts as well as in the older unvaccinated cohorts. No indications of rapidly waning immunity after vaccination were found. There are indications of low virus circulation in the last few years. The very high seroprevalence in women at childbearing age is consistent with the few reported cases of congenital rubella syndrome (CRS) at present. However, individuals in the age group of 1-9 years who are not vaccinated for religious or other reasons have a considerably lower seroprevalence and thus there is a potential risk of a CRS outbreak in the future.     

Progress toward elimination of rubella and congenital rubella syndrome--the Americas, 2003-2008

In 2003, the Pan American Health Organization (PAHO) adopted a resolution calling for rubella and congenital rubella syndrome (CRS) elimination in the Americas by the year 2010. Elimination was defined as the interruption of endemic rubella virus transmission in all countries of North America, Central America, South America, and the Caribbean for more than 12 months and no occurrence of CRS cases attributed to endemic transmission. To accomplish this goal, PAHO developed a rubella and CRS elimination strategy (3) to 1) introduce rubella-containing vaccine (RCV) into routine vaccination programs of all countries for children aged 12 months and reach >/=95% coverage in all municipalities, 2) conduct a one-time mass campaign among adolescents and adults and periodic follow-up campaigns among children aged <5 years, and 3) integrate rubella surveillance with measles surveillance and initiate CRS surveillance. During 1998-2006, confirmed rubella cases decreased 98% (from 135,947 to 2,998) in the Americas. However, in 2007, rubella outbreaks with a total of 13,014 cases occurred in three countries (Argentina, Brazil, and Chile), primarily in males not included in previous vaccination campaigns. This report summarizes overall progress toward reaching the 2010 goal of eliminating rubella and CRS. With completion of campaigns in Argentina, Brazil, and Haiti, all countries will have implemented the recommended PAHO strategy by the end of 2008, with the expectation of reaching the 2010 rubella and CRS elimination goal.     

Progress toward control of rubella and prevention of congenital rubella syndrome --- worldwide, 2009

Rubella usually is a mild, febrile rash illness in children and adults; however, infection early in a woman's pregnancy, particularly during the first 16 weeks, can result in miscarriage, fetal death, or an infant born with birth defects (i.e., congenital rubella syndrome [CRS]). In 2000, the World Health Organization (WHO) published the first rubella vaccine position paper to guide introduction of rubella-containing vaccine (RCV) in national childhood immunization schedules. As of December 2009, a total of 130 WHO member states have introduced RCV, a 57% increase from 83 member states in 1996. In addition, goals to eliminate rubella and CRS have been established in the WHO Region of the Americas (by 2010) and the WHO European Region (by 2015), and the WHO Western Pacific Region has established targets for accelerated rubella control and CRS prevention by 2015. During 2009, a total of 121,344 rubella cases were reported from 167 member states to WHO, an 82% decrease from 670,894 cases reported in 2000 from 102 member states. This report summarizes reported rubella and CRS cases globally and progress toward global introduction and use of RCV.     

Elimination of rubella and congenital rubella syndrome--United States, 1969-2004

In October 2004, CDC convened an independent panel of internationally recognized authorities on public health, infectious disease, and immunization to assess progress toward elimination of rubella and congenital rubella syndrome (CRS) in the United States, a national health objective for 2010. Since rubella vaccine licensure in 1969, substantial declines in rubella and CRS have occurred, and the absence of endemic transmission in the United States is supported by recent data: 1) fewer than 25 reported rubella cases each year since 2001, 2) at least 95% vaccination coverage among school-aged children, 3) estimated 91% population immunity, 4) adequate surveillance to detect rubella outbreaks, and 5) a pattern of virus genotypes consistent with virus originating in other parts of the world. Given the available data, panel members concluded unanimously that rubella is no longer endemic in the United States. This report summarizes the history and accomplishments of the rubella vaccination program in the United States and the Western Hemisphere and the challenges posed by rubella for the future.     

Safety profile of rubella vaccine administered to pregnant women: A systematic review of pregnancy related adverse events following immunisation,including congenital rubella syndrome and congenital rubella infection in the foetus or infant

BackgroundData on the safety of inadvertent rubella vaccination in pregnancy is important for rubella vaccination programs aimed at preventing congenital rubella syndrome.MethodsThe association between monovalent rubella or combination vaccinations in or shortly before pregnancy and potential harm to the foetus was examined by conducting a systematic review and meta-analysis using fixed effect methods and simulation.ResultsFour cohort studies of inadvertently vaccinated and unvaccinated women were found, 15 cohorts of pregnant women who were rubella susceptible at time of inadvertent vaccination and 9 cohort studies with no information on susceptibility and case series. No case of vaccine associated congenital rubella syndrome (CRS) was identified. Cohort studies with an unvaccinated comparison group were limited in number and size, and based on these only a theoretical additional risk of 6 or more cases of CRS per 1000 vaccinated women (0% observed, upper 95% CI 0.6%) could be excluded. Based on cohorts of vaccinated rubella susceptible pregnant women a maximum theoretical risk of 1 CRS case in 1008 vaccinated women (0% observed, upper 95% CI 0.099%) was estimated. Asymptomatic rubella vaccine virus infection of the neonate was also noted (fixed effects estimate of risk overall 1.74%, 95% CI 1.21, 2.28).ConclusionThere is no evidence that CRS is caused by rubella-containing vaccines but transplacental vaccine virus infection can occur. CRS is effectively prevented by vaccination, thus the risk/benefit balance is unequivocally in favour of vaccination. The data confirm previous recommendations that inadvertent vaccination during pregnancy is not an indication for termination of pregnancy.     

The seroepidemiology of rubella in western Europe

Most of the countries in western Europe have now implemented mass infant rubella immunization programmes, instead of or in addition to selective vaccination in order to achieve the elimination of congenital rubella syndrome. The European countries Denmark, England and Wales, Finland, France, Germany, Italy and the Netherlands undertook large, national serological surveys collecting several thousand serum specimens during 1994-8. Antibodies against rubella virus were detected by a variety of enzyme immuno-assays. Comparability of the assay results was achieved by a standardized methodology. The age- and sex-stratified serological results were related to the schedules, coverage of rubella vaccination and the incidence in these countries. The results show widely differing levels of immunity to rubella both in the general population and in the specific age groups of males and females. A low rate (< 5%) of susceptibles in childhood and adolescents of both sexes was obtained only in Finland and the Netherlands. Countries such as Italy with only moderate coverage for the infant immunization programme currently have both high susceptibility levels in the general population and in the at-risk population. The likelihood is of continued epidemics of rubella with cases of congenital rubella syndrome. The continued implementation of selective vaccination will help to offset the impact of this ongoing transmission and to protect women on reaching childbearing age.     

2005年山东省部分孕期妇女风疹易感性调查

[目的]了解山东省孕期妇女风疹易感性水平,为调整风疹疫苗免疫策略提供依据。[方法]2005年,采集不同地区到医院准备分娩的20~40岁孕妇血清,采用间接酶联免疫吸附定量法检测风疹IgG抗体。[结果]检测标本3 788份,风疹抗体阳性(>20 IU/ml)的2 942人,阴性(<10 IU/ml)的314人,临界值(10~20 IU/ml)的532人,易感(临界值和阴性者)合计846人,易感率为22.33%。几何平均抗体含量(CMT)为34.93 IU/ml。不同地区风疹易感率和CMT的差异均有统计学意义(P<0.01);风疹易感率有随年龄增长而增高的趋势(P<0.01)。[结论]山东省近1/4的孕妇为风疹的易感者,有必要对育龄期妇女开展风疹疫苗接种。     

Models of strategies for control of rubella and congenital rubella syndrome—A 40 year experience from Australia

We investigated the impact of vaccination on rubella epidemiology in Australia, using a mathematical model fitted to Australian serosurvey data and incorporating pre-vaccination European estimates of rubella transmissibility. Mass infant measles–mumps–rubella (MMR) vaccination produced a 99% reduction in both rubella and congenital rubella syndrome (CRS) incidence by 2010 compared to the pre-vaccination era (1960–70). The model is consistent with reductions in CRS based on surveillance of congenital hearing impairment. Model simulations suggest that selective schoolgirl vaccination (1971–88) was associated with a 90% reduction in CRS incidence, but only a 1–4% reduction in rubella incidence. Our model predicted that these reductions in rubella were much less vulnerable to reductions in MMR vaccine coverage than for measles. In the future, a less than 15% decrease in MMR vaccine coverage is estimated to have minimal impact before 2060, but a 20% reduction may result in a 7-fold increase in rubella incidence, with the effective reproductive number R rising from 0.28 to 0.78 by 2060. The 99% reduction in both rubella and CRS incidence and low effective reproductive number (R ≤ 0.28) we documented after 2010 are consistent with Australia having achieved rubella elimination.     

Rubella in the Russian Federation: epidemiological features and control measures to prevent the congenital rubella syndrome

A review of the epidemiology of clinical rubella in the Perm region of the Russian Federation from 1979-97 showed that the incidence was about 220 cases per 100,000 population. Congenital rubella syndrome (CRS) accounted for 15% of birth defects and for about 3.5 cases of CRS per 1000 live births per year. Surveys of the seroepidemiology of rubella infection revealed that the susceptibility rate among pregnant women (i.e. rubella virus antibody haemagglutination-inhibition (HAI) assay titres < 10) was 16.5%. As serum rubella antibody HAI titres > or = 10 both prevented infection in pregnant women and protected their foetuses, serological testing has been introduced into the routine antenatal services. Pre-existing rubella antibodies were found not to interfere with the immune response to vaccination, so selective immunization was provided to girls approaching puberty and to women of childbearing age. A programme of epidemiological surveillance is being developed to define tactics for the widescale introduction of rubella vaccination.     

Rubella susceptibility in pregnant women and results of a postpartum immunization strategy in Catalonia,Spain

BackgroundElimination of congenital rubella syndrome depends not only on effective childhood immunization but also on the identification and immunization of rubella susceptible women. We assessed rubella susceptibility among pregnant women and evaluated the adherence and response to postpartum immunization with measles, mumps and rubella (MMR) vaccine.MethodsCross-sectional study of women who gave birth at the Hospital Clinic de Barcelona (Spain) between January 2008 and December 2013. Antenatal serological screening for rubella was performed in all women during pregnancy. In rubella-susceptible women, two doses of MMR vaccine were recommended following birth. We evaluated rubella serological response to MMR vaccination in mothers who complied with the recommendations.ResultsA total of 22,681 pregnant women were included in the study. The mean age was 32.3 years (SD 5.6), and 73.6% were primipara. The proportion of immigrants ranged from 43.4% in 2010 to 38.5% in 2012. The proportion of women susceptible to rubella was 5.9% (1328). Susceptibility to rubella declined with increasing maternal age. Immigrant pregnant women were more susceptible to rubella (7.6%) than women born in Spain (4.6%). Multivariate analyses showed that younger age (≤19 years) aOR 1.7 (95% CI 1.1–2.5), primiparas aOR 1.3 (95% CI 1.1–1.5) and immigrant women aOR 1.6 (95% CI 1.4–1.8) were more likely to be susceptible. The second dose of MMR vaccine was received by 57.2% (718/1256) of rubella-susceptible women, with the highest proportion being immigrant women compared with women born in Spain. After vaccination, all women showed rubella immunity.ConclusionsThe higher rubella susceptibility found in the three youngest age groups and in immigrant women highlights the relevance of antenatal screening, in order to ensure identification and postpartum immunization. The postpartum immunization strategy is an opportunity to protect women of childbearing age and consequently prevent occurrence of CRS, and to increase vaccination coverage against rubella and other vaccine-preventable diseases.     

An epidemiological assessment towards elimination of rubella and congenital rubella syndrome in Singapore

ObjectiveIn line with regional and global goals for the elimination of rubella and congenital rubella syndrome (CRS), we reviewed the epidemiological situation in Singapore, based on surveillance reports on rubella and CRS, national immunization coverage and seroprevalence surveys. The aim of our review was to identify current gaps and steps taken to achieve the targets set by the World Health Organization (WHO) Western Pacific Regional Office (WPRO).MethodsEpidemiological data on clinical and laboratory-confirmed rubella cases, including CRS, notified to the Communicable Diseases Division, Ministry of Health, Singapore, from 2003 to 2013 were collated and analyzed. Vaccination coverage against rubella was obtained from the National Immunization Registry and School Health Services of the Health Promotion Board. The changing prevalence of rubella was determined from periodic serological surveys.FindingsThe incidence of indigenous rubella cases per million population decreased from 37.2 in 2008 to 7.6 in 2013 and there had been no indigenous case of CRS in 2012 and 2013. Therapeutic abortions performed due to rubella infections had become uncommon. The annual measles, mumps, and rubella (MMR) vaccination coverage in childhood population remained high ranging from 93% to 96%. The overall susceptibility to rubella in women aged 18–44 years had reduced significantly from 15.8% in 2004 to 11.0% in 2010. The prevalence of IgG antibody against rubella among Singapore children aged 1–17 years was maintained at 87.3% in 2008–2010.ConclusionAll available data indicated that Singapore has made good progress towards the elimination of rubella and CRS. It has attained the targets set by the WHO WPRO for 2015. In preparation for verification of rubella elimination, an enhanced surveillance system has been implemented to ensure that all reported cases are laboratory confirmed, and genotyping of rubella virus strains isolated is carried out to provide evidence for interruption of endemic transmission.     

Sero-epidemiology of rubella in the urban population of Addis Ababa, Ethiopia

We conducted a community-based cluster sample survey of rubella sero-epidemiology in Addis Ababa, Ethiopia in 1994. Among 4666 individuals for whom complete data were available, rubella antibody prevalence was 91% (95% confidence interval: 90, 92). On multivariable analysis, seroprevalence was lower among individuals who were resident in Addis Ababa for 1 year or less. Approx. 50% seroprevalence was attained by age 4 years, and the estimated average age at infection was 5.2 years. The highest age-specific force of infection was estimated to occur in 5- to 9-year-olds. The early age at infection corresponded with a low estimated incidence of congenital rubella syndrome (CRS) of 0.3 per 1000 live births, equivalent to nine cases of CRS in 1994. The predicted critical level of immunity for elimination of rubella via vaccination was 85-91%, requiring 89-96% coverage with a vaccine of 95% effectiveness. Unless very high coverage of rubella vaccine could be guaranteed, the introduction of childhood vaccination could increase the incidence of CRS in Addis Ababa.     

A systematic review of rubella vaccination strategies implemented in the Americas: impact on the incidence and seroprevalence rates of rubella and congenital rubella syndrome

Objective

To evaluate the impact of rubella vaccination strategies on the rates of acquired rubella and congenital rubella syndrome in the Americas.

Methods

We conducted a systematic review of the literature (MEDLINE, PubMed, EMBASE, Cochrane Library, Artemisa Database, LILACS Database, Evidence Portal, VHL-PAHO Portal, Scielo, and Grey-Literature sources) that was published from 1969–2010. We included studies on rubella incidence and seroprevalence rates that were associated with rubella vaccination. The quality of the studies was evaluated according to international guidelines.

Results

A total of 14 studies were identified: 2 clinical trials, 2 cohort studies, 3 transversal studies, 5 ecological studies, and 2 mathematical models. Childhood vaccination reduced the incidence of rubella by 23.6% to 99.6%, increased the occurrence of epidemic cycles in Argentina and in the United States, and shifted the illness to susceptible adults. Vaccination strategies that focused on women and children in Brazil were associated with a 5.5-fold greater incidence of rubella in men leading to new outbreaks and CRS. A combined vaccination strategy with a universal approach that included routine vaccination for boys, girls, women, and men in Mexico and in Costa Rica reduced the incidence of rubella by more than 98% and led to absence of CRS since 2008. A medium and a low risk of bias were found in 3 and 4 articles, respectively.

Conclusion

The results of this review demonstrate that the combined vaccination strategy with a universal approach was the most effective strategy as evidenced by a drastic reduction in the number of cases and the interruption of endemic transmission of rubella in the Americas.     

Surveillance for congenital rubella in Australia since 1993: Cases reported between 2004 and 2013

Objective

To describe the epidemiology of congenital rubella infections notified to the Australian Paediatric Surveillance Unit (APSU) from 2004 to 2013 and compare that with previously published APSU data for 1993–2003.

Methods

Active national surveillance for congenital rubella infection has been conducted through the APSU since 1993. Monthly reporting by child health clinicians according to pre-defined case criteria triggers requests for clinicians to provide de-identified clinical, epidemiological, and laboratory information. Data were extracted for cases reported between January 2004 and December 2013 and compared with previous years.

Results

Five cases of confirmed congenital rubella infection were identified during the reporting period. All five infants had defects consistent with congenital rubella syndrome (CRS). Four of the infants were born in Australia during the study period, and all were born to mothers born overseas. Three of the five mothers had not had rubella vaccination, and in two vaccination status was unknown, although both were from countries without routine rubella immunization programmes. Since 1993, there have been 57 notifications of congenital rubella infection to the APSU; 40 of these infants were born between January 1993 and December 2013, of whom 34 had confirmed CRS.

Conclusions

Congenital rubella infection in Australia is predominantly among children born to unimmunized immigrant mothers. Migrant women born in rubella endemic countries without routine immunization remain an important group to target for vaccination. Rubella-susceptible women, especially those in the early stages of pregnancy, should also carefully consider the risks of travelling to rubella endemic countries.