A 16-year review of seroprevalence studies on measles and rubella

The determination of the seroprevalence of vaccine-preventable diseases is critical in monitoring the efficacy of vaccination programmes and to assess the gaps in population immunity but requires extensive organisation and is time and resource intensive. The results of the studies are frequently reported in peer-reviewed scientific, government and non-government publications. A review of scientific literature was undertaken to advise the development of WHO guidelines for the assessment of measles and rubella seroprevalence. A search of the National Library of Medicine’s PubMed online publications using key words of ‘measles’, ‘rubella’, combined with ‘serosurvey’, ‘seroprevalence’, ‘immunity’ and ‘population immunity’ was conducted. A total of 97 articles published between January 1998 and June 2014 were retrieved, 68 describing serosurveys for measles and 58 serosurveys for rubella, conducted in 37 and 36 different countries respectively. Only 13 (19%) and 8 (14%) respectively were UN classified “least developed countries”. The study sample varied markedly and included combinations of male and female infants, children, adolescents and adults. The study sizes also varied with 28% and 33% of measles and rubella studies respectively, having greater than 2000 participants. Microtitre plate enzyme immunoassays were used in 52 (76%) measles studies and 40 (69%) rubella studies. A total of 39 (57%) measles and 44 (76%) rubella studies reported quantitative test results. Seroprevalence ranged from 60.8% to 95.9% for measles and 53.0% to 99.3% for rubella studies. The review highlighted that infants lost maternally-acquired immunity within 9 months of birth and were unprotected until vaccination. Two groups at higher risk of infection were identified: young adults between the ages of 15 and 30 years and immigrants.     

Durability of humoral immune responses to rubella following MMR vaccination

BackgroundWhile administration of the measles-mumps-rubella (MMR-II®) vaccine has been effective at preventing rubella infection in the United States, the durability of humoral immunity to the rubella component of MMR vaccine has not been widely studied among older adolescents and adults.MethodsIn this longitudinal study, we sought to assess the durability of rubella virus (RV)-specific humoral immunity in a healthy population (n = 98) of adolescents and young adults at two timepoints: ~7 and ~17 years after two doses of MMR-II® vaccination. Levels of circulating antibodies specific to RV were measured by ELISA and an immune-colorimetric neutralization assay. RV-specific memory B cell responses were also measured by ELISpot.ResultsRubella-specific IgG antibody titers, neutralizing antibody titers, and memory B cell responses declined with increasing time since vaccination; however, these decreases were relatively moderate. Memory B cell responses exhibited a greater decline in men compared to women.ConclusionsCollectively, rubella-specific humoral immunity declines following vaccination, although subjects’ antibody titers remain well above the currently recognized threshold for protective immunity. Clinical correlates of protection based on neutralizing antibody titer and memory B cell ELISpot response should be defined.     

风疹易感人群婚前风疹疫苗接种预防先天性风疹综合征

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

烟台市区风疹爆发的流行病学调查

本文报告了1987年2~5月间烟台市区幼儿园、小学等集体机构发生的一起出疹性疾病。经调查和血清学检测证实为风疹。总罹患率为23.99%,有的班级高达83.33%。具有流行迅速、发病集中、临床表现较重等特征。其中一例于发疹后期并发脑炎死亡。     

2000年广西麻疹疑似病例血清学监测分析

目的了解麻疹的血清流行病学特征 ,探讨麻疹与风疹之间的血清学鉴别诊断。方法采用酶联免疫吸附法对714例RFIs的血清标本进行麻疹IgM和风疹IgM抗体检测 ,对204例麻疹IgM抗体阳性的血清标本进行麻疹IgG抗体检测。结果麻疹IgM阳性率为45.7 % ,风疹IgM抗体阳性率为27.5%。在出疹后4～14天采集的血清标本其麻疹IgM和风疹IgM抗体阳性检出率最高。麻疹IgM阳性数以1～14岁为主 ,1～6岁最高 (44.5% ) ,风疹IgM阳性数是7～14岁为最高 (73.5% ) ;麻疹IgG检出<1:200为76例 (27.7 % ) ,1:200为59例 (21.5% ) ,1:800为17例(6.2 %) ,1:3200为25例(9.1 %) ,≥1:12800为27例(9.8 %)。结论采血时间与检出率密切相关 ;采集血清标本要注意质量和采集时间 ;麻疹患者与风疹患者有一定的年龄差距 ,风疹是最主要的需要与麻疹相鉴别的RFIs,未经实验室诊断极易发生误诊 ;应提高麻疹实验室诊断的及时性、准确性和敏感性 ,建议有条件的地区开展麻疹抗体血清学检测     

北京和重庆市育龄期妇女风疹抗体水平调查

目的了解北京和重庆市育龄期妇女风疹抗体水平,为控制先天性风疹综合征(CRS)提供科学依据。方法2006年6~8月随机抽取北京和重庆市各1个区作为调查点,对20~39岁育龄期妇女623人(北京市311人,重庆市312人)进行血清流行病学调查。结果北京和重庆市育龄期妇女风疹抗体阳性率分别为85.21%和78.53%,自然感染获得抗体阳性率分别为85.08%和77.89%;风疹抗体分布与年龄、地区有关,随着年龄的增长抗体阳性率和几何平均浓度有下降的趋势。结论制定科学的风疹疫苗使用策略和免疫程序,提高育龄期妇女的免疫力,是减少CRS发病的有效手段。     

Predicting the dynamic effects of rubella vaccination programmes

In the Netherlands, prepubertal girls have been vaccinated against rubella since 1974 (the UK strategy). Recently the Dutch Health Council advocated the introduction of an elimination strategy: vaccination of 1- and 9-year-old children. Dynamic effects of both strategies are studied using deterministic and stochastic models. Estimates of several epidemiological parameters are given. All computations and simulations were performed using as much field data as possible. Under the old strategy a new equilibrium is expected around the years 1995 to 2000; the new strategy is estimated to eliminate rubella (CRS) in large parts of the population 3 to 5 years after its initiation. Possible consequences of the new strategy on a cluster of people who refuse vaccination are investigated.     

重组风疹病毒外膜蛋白E1的表达及其在血清学中的初步应用

目的 在大肠埃希菌中表达重组风疹病毒外膜蛋白E1,用其作为包被抗原,建立一种用于诊断风疹病毒感染的ELISA检测方法 .方法 通过基因重组的方式构建表达质粒并在大肠埃希菌中表达风疹病毒外膜蛋白E1,蛋白纯化后作为包被抗原,用ELISA的方法 检测世界卫生组织(WHO)的风疹检测质控血清以及来自广西桂林的未知血清样本.结果 采用WHO用于风疹检测的质控血清对所表达的重组抗原的抗原性进行鉴定,通过试验,特异性、敏感性均为100%.用表达的抗原对来自我国广西的200份未知血清样本进行风疹病毒外膜蛋白抗体的检测,阳性率为93%,与文献报道的我国其他地区风疹病毒抗体阳性率基本一致.结论 通过实验我们表达了具有良好抗原性的风疹病毒外膜蛋白E1,为进一步研究风疹病毒感染的实验室诊断技术奠定了基础.     

Real-time PCR检测风疹病毒方法学建立及临床应用

为了建立一种能广泛应用于临床快速、简便、灵敏度和特异性较好的风疹病毒(RV)定量诊断方法。针对RV基因保守序列设计两对引物和一条荧光双标记探针。将PCR扩增所得到的产物片段克隆,作为定量检测的标准品,进行Real-time PCR检测,绘制标准曲线。将此方法和ELISA试剂盒平行检测50份孕妇血清,评估两种方法检出阳性率的差异显著性。Real-time PCR法能较好地检出RVcDNA载量。曲线的相关系数(r)为0.998,可检测线性范围大约在103~109copies/μl,灵敏度接近103copies/μl;批间、批内CV值分别为3.36%、0.94%;也有较好的特异性。与经典的ELISA方法相比,有显著性差异。Real-time PCR方法操作简单、快速,并能避免PCR后处理导致的假阳性污染,实现实时定量。此方法对RV感染的临床诊断和疗效判断等方面有较大的指导意义。     

新生儿TORCH感染的血清学检测与临床分析

目的 对新生儿进行TORCH感染的血清学检查及临床表现分析。方法 用ELASA法检测血清中TORCH(弓形体、风疹病毒、巨细胞病毒、单纯疱疹病毒)IgM。结果 2000年1月至2003年1月本院新生儿重症监护室(NICU)共收治新生儿l554例，其中48例为TORCH感染，巨细胞病毒感染率最高占52．1％；风疹病毒感染占33．3％；单纯疱疹病毒感染占14．6％。未发现弓形体抗体阳性的患儿。结论 新生儿TORCH感染可造成多器官损伤，主要为听力异常、高胆红素血症和肝功能异常、神经系统损伤、心肌损伤、血小板减少、先天性心脏病。计划免疫、母亲孕期筛查、新生儿早期筛查、干预治疗非常重要。