Progress toward elimination of measles and prevention of congenital rubella infection--European region, 1990-2004

The European Region (EUR) of the World Health Organization (WHO) comprises 52 member countries, with an estimated population of 876 million. In 1998, the Regional Committee for EUR resolved to interrupt indigenous measles transmission by 2007 and reduce the incidence of congenital rubella syndrome (CRS) in all countries to <1 per 100,000 live births by 2010. In 2002, progress toward these measles and rubella targets was further encouraged with development of the Strategic Plan for Measles and Congenital Rubella Infection in the WHO European Region, which outlines an integrated approach to achieving both disease targets by 2010 by implementing six key strategies. This report presents data on measles, rubella, and CRS control in EUR during 1990-2004 and summarizes progress halfway through the implementation of the strategic plan.     

Research priorities for global measles and rubella control and eradication

In 2010, an expert advisory panel convened by the World Health Organization to assess the feasibility of measles eradication concluded that (1) measles can and should be eradicated, (2) eradication by 2020 is feasible if measurable progress is made toward existing 2015 measles mortality reduction targets, (3) measles eradication activities should occur in the context of strengthening routine immunization services, and (4) measles eradication activities should be used to accelerate control and elimination of rubella and congenital rubella syndrome (CRS). The expert advisory panel also emphasized the critical role of research and innovation in any disease control or eradication program. In May 2011, a meeting was held to identify and prioritize research priorities to support measles and rubella/CRS control and potential eradication activities. This summary presents the questions identified by the meeting participants and their relative priority within the following categories: (1) measles epidemiology, (2) vaccine development and alternative vaccine delivery, (3) surveillance and laboratory methods, (4) immunization strategies, (5) mathematical modeling and economic analyses, and (6) rubella/CRS control and elimination.     

Measles, rubella, and congenital rubella syndrome--United States and Mexico, 1997-1999

In 1996, the Immunization Working Group of the Mexico-United States Binational Commission was established to enhance coordination of disease surveillance, assure high vaccination coverage in both countries, and hasten the elimination of vaccine-preventable diseases. The United States and Mexico share the Pan American Health Organization (PAHO) goal of measles elimination by 2000. The United States also established a goal of eliminating indigenous rubella and congenital rubella syndrome (CRS) by 2000. This report summarizes the measles and rubella vaccination and surveillance data for the United States and Mexico for 1997-1999.     

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.     

Global Measles and Rubella Laboratory Network, January 2004-June 2005

Measles continues to be a leading cause of childhood morbidity and mortality in developing countries and an outbreak threat in the majority of countries. In 2000, measles was considered the fifth leading cause of childhood mortality, and the World Health Organization (WHO) estimated that approximately 777,000 measles-associated deaths occurred worldwide. In 2001, WHO and the United Nations Children's Fund (UNICEF) developed a 5-year strategic plan, endorsed by the World Health Assembly in 2003, to reduce measles mortality by 50% by 2005 (relative to 1999 estimates) and to achieve and maintain interruption of indigenous measles transmission in large geographic areas with established measles elimination goals. This plan included strengthening routine vaccination coverage, providing a second opportunity for measles immunization to children, improving measles case management, and improving surveillance with laboratory confirmation of suspected measles cases. To date, four of six WHO regions have established measles elimination targets: the Americas Region (AMR) by 2000, the European Region (EUR) by 2010, the Eastern Mediterranean Region (EMR) by 2010, and the Western Pacific Region (WPR) by 2012. The remaining two WHO regions, the African (AFR) and South East Asian (SEAR) regions, are continuing work toward the measles mortality reduction goal. Likewise, to reduce the burden of disease from congenital rubella syndrome (CRS), currently estimated at 100,000 cases per year worldwide, several countries have developed or continue to develop rubella control programs, and AMR and EUR have established regional rubella elimination and CRS reduction goals, respectively. Because improved global surveillance is essential for monitoring progress toward mortality reduction and elimination of these diseases, WHO established the Measles and Rubella Laboratory Network (LabNet) in 2003 to promote case identification and confirmation. This report provides an update on the development of LabNet during January 2004-June 2005 and describes the geographic distribution of measles and rubella virus genotypes as of June 2005.     

Control of rubella and congenital rubella syndrome (CRS) in developing countries, Part 2: Vaccination against rubella.

In 1995-96 we conducted a review of rubella immunization strategies. Worldwide, 78 countries (more than one-third) reported a national policy of using rubella vaccine. This was closely related to country economic status. Based on the United Nations country classification, rubella vaccine is used in 92% of industrialized countries, 36% of those with economies-in-transition, and 28% of developing countries. Cases of congenital rubella syndrome (CRS) may be prevented as follows: by providing direct protection to women and/or schoolgirls (a selective vaccination strategy); by vaccinating boys and girls to provide indirect protection by reducing the transmission of rubella virus (a childhood vaccination strategy); or by a combination of these approaches (a combined strategy). A combined strategy was most commonly reported (60% of countries); seven countries (9%) reported a selective strategy; and 24 countries (31%) reported only childhood immunization. Experience has shown that it is essential to include vaccination of women of childbearing age in any rubella control strategy. Childhood vaccination alone may pose a risk of an increase in CRS cases. Although many countries have introduced rubella vaccine, few report any data on the impact of vaccination. Countries using rubella vaccine need to establish surveillance for rubella and CRS and monitor coverage in each of the target groups.     

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.     

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.     

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.     

Progress and challenges in measles and rubella elimination in the WHO European Region

IntroductionDespite availability of safe and cost-effective vaccines to prevent it, measles remains one of the significant causes of death among children under five years of age globally. The World Health Organization (WHO) European Region has seen a drastic decline in measles and rubella cases in recent years, and a few of the once common measles genotypes are no longer detected. Buoyed by this success, all Member States of the Region reconfirmed their commitment in 2010 to eliminating measles and rubella, and made this a central objective of the European Vaccine Action Plan 2015–2020 (EVAP). Nevertheless, sporadic outbreaks continue, recently affecting primarily adolescents and young adults with no vaccination or an incomplete vaccination history. The European Regional Verification Commission for Measles and Rubella Elimination was established in 2011 to evaluate the status of measles and rubella elimination based on documentation submitted annually by each country’s national verification committee.DiscussionEach country’s commitment to eliminate measles and rubella is influenced by competing health priorities, and in some cases lack of capacity and resources. All countries need to improve case-base surveillance for both measles and rubella, ensure documentation of each outbreak and strengthen the link between epidemiology and laboratory data. Achieving high coverage with measles- and rubella-containing vaccines will require a multisectoral approach to address the root causes of lower uptake in identified communities including service delivery challenges or vaccine safety concerns caused by circulating myths about vaccination.ConclusionsThe WHO European Region has made steady progress towards eliminating measles and rubella and over half of the countries interrupted endemic transmission of both diseases by 2015. The programmatic challenges in disease surveillance, vaccination service delivery and communication in the remaining endemic countries should be addressed through periodic evaluation of the strategies by all stakeholders and exploring additional opportunities to accelerate the ongoing elimination activities.     

Accelerated rubella control and the prevention of congenital rubella syndrome]

Congenital rubella syndrome (CRS) is associated with substantial morbidity and mortality and with high costs. Today, as a result of improved vaccination and epidemiological surveillance efforts directed at eradicating measles from the Western Hemisphere, there has been a notable increase in the ability to detect, prevent, and control rubella and CRS. The importance of these measures is undeniable, and this piece examines the components that are essential in moving ahead to reduce these major public health problems in Latin America and the Caribbean. One step in that direction would be to integrate the surveillance of measles with that of rubella and CRS.     

上海市麻疹、流行性腮腺炎、风疹抗体水平调查分析

[目的 ]　了解本市健康人群麻疹、腮腺炎、风疹的抗体水平。　 [方法 ]　采集 0～ 5 0岁健康人群血标本 5 43份 ,检测麻疹、腮腺炎、风疹抗体。　 [结果 ]　小于 8月龄组麻疹抗体GMT最低 ,接种麻疹疫苗后抗体GMT显著升高 (P<0 .0 0 1) ;小于 8月龄组及 8月龄组风疹抗体水平最低 ,1岁接种疫苗后风疹抗体显著升高 (P <0 .0 0 1) ,但随着年龄的增长抗体水平有所下降 ,抗体阳性率维持在 85 %以上 ;小于 8月龄组及 8月龄组流行性腮腺炎抗体水平最低 ,1岁以上各年龄组抗体水平显著上升 (P <0 .0 0 1)。　 [结论 ]　上海市现阶段实行麻疹疫苗、MMR疫苗的接种程序比较合理和有效 ,但应该进一步开展上海市育龄期妇女风疹抗体水平调查和MMR疫苗免疫持久性观察 ,研究预防未及龄儿童麻疹疫苗免疫策略、育龄期妇女接种风疹疫苗免疫策略 ,预防先天性风疹综合征     

Measles and rubella eradication in the Americas

The challenge for regions embarking on measles elimination will be to maintain high population immunity with excellent vaccination coverage and high-quality surveillance. Meeting this challenge will be especially critical for dealing with importations of measles virus that will occur as long as the virus is circulating anywhere in the world. Implementation of measles elimination strategies will uncover the "hidden" disease burden of rubella and congenital rubella syndrome. As was the experience in countries of Latin America and the Caribbean (LAC), integrating the elimination of measles with the elimination of rubella will greatly enhance the capacity of countries to sustain progress in the reduction of measles mortality. Countries of LAC prioritized the routine national immunization program over short-term successes. While doing so, they have also encountered new opportunities to expand the benefits of disease control and elimination activities to other aspects of public health, most importantly towards improving health care for women and newborns and reducing inequities in health in the region's poorest communities. Implementation of similar strategies could lead to the global eradication of measles, rubella, and congenital rubella syndrome early this century, while strengthening routine immunization programs, and developing the capacity to introduce new and underutilized vaccines.     

Waning antibodies in measles and rubella vaccinees--a longitudinal study

The evolution of measles- and rubella-specific serum IgG was followed in a longitudinal study in 224 young adolescent vaccinees, with or without boost vaccination before or during the 6.8-year observation period. Antibody titres were monitored by enzyme immuno assay (Enzygnost, Dade-Behring). After revaccination (second dose) rubella seropositivity rate increased from 92.1 to 100%, whereas measles seroprevalence (about 90%) did not significantly change between the paired sera. Significantly higher IgG (> three-fold) in the second serum of 5.2% (measles) and 7.8% (rubella) of participants with low antibodies (measles: < 1500 mIU; rubella < 40 IU) in first serum, suggest a secondary immune response (SIR) during the study period, only partially explained by revaccination. Excluding individuals with SIR, minimal annual antibody decay rates of -2.9% (confidence interval, CI: -0.7 to -4.8%) for rubella and -1.6% (CI: -0.1 to -3%) for measles were determined in participants with single dose vaccination. Thus, two-dose vaccination was adequate to protect women from rubella infection at least during childbearing age. Similarly only few individuals may become seronegative for measles again after successful vaccination due to minimal waning of low antibody levels (< 1500 mIU). However, as a result of a more rapid decay of high-titre (> 1500 mIU) antibodies (-2.4%/year), many vaccinees may eventually become susceptible to vaccine-modified measles (VMM) and consequently complicate measles control strategies.     

The pre-vaccination epidemiology of measles, mumps and rubella in Europe: implications for modelling studies

Data on the pre-vaccination patterns of infection for measles, mumps and rubella are collated from a number of European countries in order to compare the epidemiology of the three viruses. Key epidemiological parameters, such as the age-specific force of infection and the basic reproduction number (R0) are estimated from case notification or serological data using standard techniques. A method is described to compare force of infection estimates derived from serological data. Analysis suggests that the pre-vaccination patterns of measles and mumps infection in the different countries were similar. In contrast, the epidemiology of rubella was highly variable between countries. This suggests that it may be acceptable to use parameter values estimated from other countries to model measles and mumps transmission, but that this approach to modelling rubella transmission requires more caution. Estimates of R0 depend on underlying mixing assumptions. Constraints were placed on R0 estimates by utilising knowledge of likely mixing patterns. The estimates for R0 were highest for measles, intermediate for mumps, and generally lowest for rubella. Analysis of within- and between-age-group transmission rates suggested that mumps transmission tends to be more concentrated within young children than the other two viruses. The implications for the design of immunization programmes are that mumps may be the easiest to control via infant immunization since it is predominantly transmitted between the very young and the variability in rubella epidemiology requires that careful consideration of the possible effects of vaccination options should be made using local data when planning rubella immunization programmes.     

Global landscape of measles and rubella surveillance

BackgroundAll six World Health Organization (WHO) regions have committed to eliminate measles, and three WHO regions have committed to eliminate rubella. One of the key tenets of measles and rubella elimination is to have a strong surveillance system in place. The presence of a case-based measles and rubella surveillance system that is national, population-based, provides laboratory confirmation, and directs action, is one of the requirements for elimination-standard surveillance.MethodsIn order to understand the global landscape for measles and rubella surveillance, a questionnaire was sent to all 194 WHO member states (herein referred to as countries) requesting information on how surveillance was conducted for measles, rubella, and congenital rubella syndrome. Data were supplemented with information provided to WHO through other reporting mechanisms and by national policy documents available to the public. Frequencies and percentages were calculated.ResultsData were available to review from 164 (85%) countries, although not every country responded to every question. Case-based, population-based, national surveillance with laboratory confirmation was reported to be conducted in 136 (86%) of 158 countries for measles and 122 (77%) of 158 countries for rubella. Congenital rubella syndrome surveillance was reported to be conducted by 126 (77%) of 163 countries. Gaps were noted in the quality of measles-rubella surveillance conducted, and 26 (16%) of 158 countries reported not including all healthcare providers as mandatory reporters.ConclusionsMany countries reported having some of the essential components in place to conduct elimination-standard surveillance for measles and rubella; however, in order to achieve elimination, the quality of surveillance needs to improve to detect all cases. In those countries without these essential components of elimination-standard surveillance, the first step is to implement these components.     

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。     

Increase of vaccination coverage by mass media and individual approach: intensified measles, mumps, and rubella prevention program in Finland

In the 1970s, mass vaccination projects were started in various parts of the world against measles and congenital rubella, with eradication as the final goal. In many developing and industrial countries, including Finland, the elimination of measles failed because of low vaccination coverage. In Finland, a combined measles, mumps, and rubella (Virivac) vaccination program was started in 1982. Computerized recording of the vaccinated children was considered necessary and was integrated with the population registry to identify the hard-to-reach families. Several interventions improved compliance: a mass media campaign and notification of nonvaccinated children to local health professionals and parents. All successive campaigns increased vaccination coverage significantly, with the notification of parents about their nonvaccinated child being especially effective. A vaccination coverage of over 96% was achieved, which theoretically prevents measles, mumps, and rubella transmission.     

The strategy for prevention of measles and rubella prevalence with measles–rubella (MR) vaccine in Japan

To eliminate the indigenous measles and rubella virus by 2012 in Japan, the strategy for prevention of measles and rubella prevalence with measles-rubella (MR) vaccine was proposed. Since the vast majority of 1-year old infants are susceptible to measles and rubella, the first MR vaccine should be administered at 1-year old to sustain the herd immunity. Since significant elevation of measles and rubella antibody titers was estimated in a half of children after the second dose, the second dose of MR vaccine within 1 year before elementary school entry is the effective maneuver. Moreover, supplement MR vaccination to the teenage group and 20–29 years’ group might be necessary, because the mean measles antibody titers in this group were significantly lower compared with those in the older individuals’ groups.     

天津市麻疹风疹及流行性腮腺炎抗体水平分析

目的了解天津市健康人群麻疹、风疹、流行性腮腺炎抗体水平,评价疫苗接种需求。方法2007年3月采集0~57岁健康人群608人份血样品,用ELISA方法定量检测麻疹、风疹、流行性腮腺炎IgG抗体水平。运用直线相关分析抗体阳性率,保护率GMC与疾病发病率之间的关系,P0.05为差异有统计学意义。结果麻疹、风疹和流行性腮腺炎疫苗接种率分别为70.39%、16.78%和12.34%;抗体阳性率分别为91.78%,65.79%和73.52%;抗体几何平均浓度(GMC)分别为2 488.10 IU/L、200.4 IU/ml和759.91 U/ml。麻疹抗体阳性率,保护率与发病率存在明显相关关系(P0.01),而GMC与麻疹发病率没有显著性相关;风疹和流行性腮腺炎抗体阳性率、GMC与发病率无相关关系。结论本次调查显示2007年天津市麻疹人群抗体GMC总体保持在较高水平。风疹、流行性腮腺炎疫苗接种率和抗体水平较低,2剂次的麻腮风疫苗(MMR)纳入免疫规划既有助于消除麻疹,也有利于控制风疹和流行性腮腺炎。