病毒性传染病

山西省2003年正常人群血清麻疹IgG抗体检测分析——郑蕾等(山西太原市山西省疾病预防控制中心030012)《中华临床新医学》2004，4(12)：1077-1078[了解山西正常人群麻疹抗体水平。方法：随机选择4个县，4个年龄组正常人群，采集840份血清，用间接酶联免疫吸附实验(ELISA)测定血清中的IgG抗体。结果：不同县间麻疹抗体检出率和几何平均滴度均有显性差异；各年龄组间也有明显差异，2．4岁年龄组阳性率和几何平均滴度最低。结论：进一步加强麻疹的计划免疫，尤其免疫水平较低的地区更要加强对小年龄组的免疫，以控制麻疹的流行。]     

新疆克拉玛依市0～6岁儿童免疫规划针对传染病抗体水平调查

目的了解新疆克拉玛依市免疫规划针对传染病的抗体水平、预测流行趋势并评价免疫效果,为进一步做好免疫规划工作提供科学依据。方法分层随机抽取克拉玛依市0~6岁儿童143人,采集血标本,检测麻疹、百日咳、白喉、乙型肝炎和甲型肝炎的抗体水平。结果白喉、麻疹、甲型肝炎、乙型肝炎及百日咳Ig G抗体的阳性率依次为100.0%、90.9%、89.9%、79.0%和49.7%,麻疹抗体保护性率为76.9%,麻疹、百日咳、白喉、乙型肝炎、甲型肝炎抗体几何平均浓度(GMC)分别为2 057.3 m IU/ml、34.2 IU/ml、3.6 IU/ml、838.1 m IU/ml、476.5 m IU/ml;不同年龄组麻疹抗体保护率差异有统计学意义(χ~2=40.38,P0.05),麻疹(χ~2=88.80)、百日咳(χ~2=13.96)和甲型肝炎(χ~2=28.14)抗体阳性率差异亦有统计学意义(均P0.05);不同地区人群乙型肝炎抗体阳性率差异有统计学意义(χ~2=12.25,P0.05),不同性别人群百日咳(χ~2=0.32)、白喉(χ~2=0.00)、乙型肝炎(χ~2=2.74)和甲型肝炎(χ~2=0.98)的抗体阳性率差异均无统计学意义(P0.05);不同免疫剂次麻疹(χ~2=70.15)和甲型肝炎(χ~2=19.95)抗体阳性率差异有统计学意义(P0.05),且抗体保护率差异亦有统计学意义(χ~2=24.77,P0.05)。结论新疆克拉玛依市0~6岁儿童麻疹、白喉及甲型肝炎抗体阳性率维持在较高水平,已达到卫生部规定的85%目标,但乙型肝炎和百日咳抗体阳性率偏低,说明此部分人群易受相应传染病的侵袭。     

2018年大理州健康人群麻疹抗体水平分析

目的　了解2018年大理州健康人群麻疹抗体水平及麻疹流行情况,评估麻疹疫苗预防接种效果,为制定大理州麻疹的预防控制策略提供科学依据。方法　通过分层整群抽样方法调查2018年大理州3783名健康者,应用酶联免疫吸附法测定血清中麻疹IgG抗体,采用描述性流行病学方法对麻疹流行情况及抗体水平监测的结果进行统计分析。结果　2018年大理州报告麻疹病例42例,发病率为11.91/100万。发病年龄主要以3岁以下婴幼儿及35～44岁年龄段的人群为主;无免疫史和免疫史不详的25例,占报告病例总数的59.53%,其抗体阳性率、保护率和抗体几何平均浓度（geometric mean concentration, GMC）最低,接种2剂次的阳性率最高,接种3剂次的保护率和GMC最高;健康人群麻疹抗体水平监测结果显示,抗体阳性率、保护率和GMC均以1～2岁组最高,＜1岁组阳性率最低,25～34岁组保护率和GMC最低,各年龄组间的差异均有统计学意义（P均＜0.05）。结论　大理州基本形成预防麻疹的免疫屏障,但3岁以下婴幼儿和35～44岁年龄段人群麻疹发病的风险高。应在加强常规免疫工作的同时,调整免疫策略,在高危人群中开展查漏补种和强化免疫,降低麻疹发病率。     

9月龄～6岁健康儿童麻疹和风疹抗体水平监测

目的 了解新疆阿克苏地区9月龄～6岁健康儿童麻疹和风疹抗体水平,及时发现免疫薄弱人群,采取针对性免疫措施.方法 采用分层随机抽样法,采集839名9月龄～6岁健康儿童血清标本,采用酶联免疫吸附试验(ELISA)检测麻疹和风疹IgG抗体.结果 839名儿童麻疹抗体阳性率为94.3％,抗体几何平均滴度(GMT)为1 541.2 mIU/ml;风疹抗体阳性率为92.1％,抗体几何平均滴度(GMT)为958.4 mIU/ml.不同免疫剂次和不同年龄组儿童麻疹、风疹抗体阳性率和GMT水平不同,差异有统计学意义(P＜0.05).结论 阿克苏地区9月龄～6岁健康儿童麻疹、风疹IgG抗体水平总体较高,但仍存在薄弱环节,1岁以下儿童是麻疹和风疹的高危人群,应加强此部分人群的针对性免疫策略.     

2017-2020年云南省剑川县健康人群麻疹抗体水平监测分析

目的 了解云南省剑川县健康人群麻疹抗体水平,为制定麻疹防控措施提供科学依据。方法 按照《云南省麻疹等疫苗针对疾病人群抗体水平监测实施方案》的要求,采用分层整群抽样方法,于2017—2020年采集剑川县1 221名健康人群静脉血标本,以ELISA法检测血清中麻疹IgG抗体。结果 2017—2020年剑川县健康人群麻疹抗体总阳性率为94.19%,各年度差异无统计学意义（χ2=7.298,P>0.05）;总保护率为66.75%,各年度差异有统计学意义（χ2=22.257,P<0.05）;各年龄组人群麻疹抗体阳性率（χ2=32.423）和保护率（χ2=103.670）差异均有统计学意义（P<0.05）;抗体保护率随年龄增长呈明显的“V”字,15～34岁仅有48.63%～50.34%人群抗体有保护率,疫情暴发风险极高;有无免疫史人群麻疹抗体阳性率差异无统计学意义（χ2=3.285,P>0.05）,保护率差异有统计学意义（χ2=10.980,P<0.05）。结论 剑川县麻疹抗体水平阳性率处于较高水平,显示免疫规划工作质量和疫苗接种效果较好;但麻疹抗体保护率偏低,现有的...     

2017—2020年云南省剑川县健康人群麻疹抗体水平监测分析

目的 了解云南省剑川县健康人群麻疹抗体水平,为制定麻疹防控措施提供科学依据。方法 按照《云南省麻疹等疫苗针对疾病人群抗体水平监测实施方案》的要求,采用分层整群抽样方法,于2017—2020年采集剑川县1 221名健康人群静脉血标本,以ELISA法检测血清中麻疹IgG抗体。结果 2017—2020年剑川县健康人群麻疹抗体总阳性率为94.19%,各年度差异无统计学意义（χ2=7.298,P>0.05）;总保护率为66.75%,各年度差异有统计学意义（χ2=22.257,P<0.05）;各年龄组人群麻疹抗体阳性率（χ2=32.423）和保护率（χ2=103.670）差异均有统计学意义（P<0.05）;抗体保护率随年龄增长呈明显的“V”字,15～34岁仅有48.63%～50.34%人群抗体有保护率,疫情暴发风险极高;有无免疫史人群麻疹抗体阳性率差异无统计学意义（χ2=3.285,P>0.05）,保护率差异有统计学意义（χ2=10.980,P<0.05）。结论 剑川县麻疹抗体水平阳性率处于较高水平,显示免疫规划工作质量和疫苗接种效果较好;但麻疹抗体保护率偏低,现有的免疫策略已不能建立起牢固的人群免疫屏障;为防范暴发疫情,在抓好儿童麻疹接种的同时,提高疫情监测敏感性和快速处置能力才能有效控制疫情。     

2006─2013年甘肃省平凉市麻疹流行特征分析

目的分析甘肃省平凉市消除麻疹工作阶段性成效,探讨下一步防控措施。方法根据中国免疫规划监测信息管理系统和麻疹监测信息报告管理系统的资料,结合健康人群麻疹IgG抗体监测,采用描述流行病学方法分析2006─2013年平凉市麻疹消除情况。结果平凉市共报告麻疹病例552例,年均发病率3.02/10万;每隔3-4年出现一个流行高峰,4-7月为高发季节,具有季节性和周期性特征;整体上仍属小年龄组发病模式,0-4岁婴幼儿和7-8岁学龄儿童形成发病高峰,呈＂双峰型＂的年龄分布特征;2009年以来健康人群麻疹抗体几何滴度（GMT）维持在较高水平,各年龄组人群麻疹抗体GMT呈现＂两头低中间高＂的现象。结论落实入托、入学查验预防接种证措施,变被动接种为主动接种,提高全民接种疫苗的自觉性;为小学一年级、高中或大学新生、育龄期妇女等特殊年龄组人群接种麻疹类疫苗,预防儿童和成人麻疹发病;督促医疗机构严格执行预检分诊制度,落实隔离治疗措施,控制院内感染。     

雅安市适龄儿童麻疹疫苗强化免疫前后抗体水平分析

目的 了解雅安市适龄儿童麻疹疫苗(MV)强化免疫前后麻疹抗体水平,为制定免疫规划,实现消除麻疹目标提供科学依据.方法 采用ELISA(酶联免疫吸附试验)法对250人份MV强化免疫前后500份血清进行麻疹IgG抗体水平检测.结果 MV强化免疫前阳性率为94.40%,麻疹IgG抗体平均浓度为1524.24mlU/ml;MV强化免疫后阳性率为100%,麻疹IgG抗体平均浓度为1 893.14mlU/ml.强免前后抗体阳性率差异有统计学意义(x2=14.40,P<0.05)),有MV免疫史的免前麻疹抗体阳性率显著高于未接种者(x2=11.95,P<0.05)).结论 雅安市适龄儿童麻疹抗体水平较高,强化免疫能提高人群免疫覆盖率,消除免疫空白.     

南京某单位新入职人员麻疹抗体现状调查

目的通过了解南京某单位新入职人员麻疹血清抗体情况,为制定免疫策略提供依据。方法采用ELISA检测南京某单位新入职人员麻疹Ig G抗体情况。结果共采样调查546人,年龄17~24岁,麻疹抗体阳性率为98.4%,抗体几何平均滴度(geometric mean titer,GMT)为1662 m IU/ml,抗体阳性率和GMT在各年龄段人群间两两比较差异无统计学意义(P均0.05);有麻疹疫苗接种史人群的麻疹抗体阳性率和GMT高于无接种史或接种史不详人群(P均0.05);不同地区及有无麻疹病史人群麻疹抗体阳性率之间差异无统计学意义(P均0.05)。结论该单位新入职人员麻疹血清抗体水平和阳性率较高,已基本形成了预防麻疹的免疫屏障。     

河北省麻疹疫苗初始强化免疫血清学效果抽样分析

目的研究河北省首次实施麻疹疫苗(MV)初始强化免疫(catch-up)血清学效果。方法通过抽样,对同一人群采集强化免疫前后双份血清以及对不同人群分别于强化免疫前后采集血清,采用酶联免疫吸附试验(ELISA)检测麻疹IgG抗体。结果强化免疫接种11920936人,接种率为92.30%;强化免疫后麻疹抗体阳性率从90%上升至99.7%以上,抗体几何平均滴度(GMT)从小于1000上升至2000以上,平均增长3倍以上;人群麻疹抗体滴度组成发生了重大变化,低抗体人群比例下降,高抗体人群比例上升;强化免疫后3年内,抗体水平仍保持在较高的水平。结论MV初始强化免疫血清学效果非常显著,极大提高了人群抗体水平,减少了易感人群的积累,使麻疹发病率保持在较低的水平。     

北京市大兴新城地区常住本、外地育龄期妇女麻疹抗体水平调查研究

目的了解大兴新城地区常住本、外地育龄期妇女现有麻疹抗体水平,为麻疹防控提供科学依据。方法 2013年1—6月对大兴新城地区常住本、外地育龄期妇女进行麻疹抗体水平测定。结果常住外地育龄期妇女的麻疹IgG抗体水平高于常住本地育龄期妇女水平(P0.05)。结论常住本地育龄期妇女的麻疹IgG抗体水平明显低于常住外地育龄期妇女,尤其是本地计划免疫外育龄期妇女存在麻疹发病危险。应加强对本地育龄期妇女的免疫接种,尤其是计划外人群。     

Age-dependent differences in IgG isotype and avidity induced by measles vaccine received during the first year of life

BACKGROUND: Measles remains an important cause of death worldwide, and vaccinating individuals at an earlier age could lead to better control of the disease. However, persistence of maternal antibody and young age affect the quantity of vaccine-induced neutralizing antibody and may also affect antibody quality. METHODS: Enzyme immunoassay was used to analyze measles virus-specific IgG levels, avidity maturation, and isotype changes, using serum samples from infants who received measles vaccine at 6 months of age and measles-mumps-rubella (MMR)-II at 12 months of age (n=26), measles vaccine at 9 months of age and measles-mumps-rubella (MMR)-II at 12 months of age (n=48), or only MMR-II at 12 months of age (n=27). RESULTS: The median IgG level was lower among infants with maternal antibody than among those without maternal antibody. Compared with median avidity indices for infants aged 12 months, median values were lower for 6-month-old infants with maternal antibody (P=.0001), 6-month-old infants without maternal antibody (P=.001), 9-month-old infants with maternal antibody (P=.03), and 9-month-old infants without maternal antibody (P=.006). The median IgG3 level was highest at 6 months of age. IgG1 was predominant at 12 months. Low avidity responses at 6 or 9 months of age did not hinder higher avidity responses or the switch to IgG1 after secondary vaccination. The 2-dose regimen did not augment the response, compared with the response in infants who received 1 dose at 12 months of age. CONCLUSIONS: Avidity and isotype maturation of measles vaccine-induced antibody are affected by age, providing insight into the ontogeny of the immune response to measles vaccine.     

Control of measles in Czechoslovakia (CSSR)

Mass immunization against measles in the Czechoslovak Socialist Republic (CSSR) began in 1969 and utilized the Czechoslovak vaccine, which corresponds in its parameters to the further-attenuated measles vaccines. The immunization rate for relevant age groups of the population (i.e., children born in 1968-1980) is already 98%-99% in 1982. Measles morbidity decreased to less than 2% of the incidence before the introduction of immunization, and the mortality now is practically negligible. The decade 1972-1982 produced significant changes in epidemiologic characteristics of measles. Of importance is the gradual shift in the age distribution of affected children to older, nonimmunized age groups. Results of yearly immunologic surveys of a broad, randomly selected population sample have become the decisive criteria for evaluation of vaccine efficacy. The program of revaccination of all children was chosen as the optimal strategy for maintaining measles elimination. This program aims at ensuring a level of herd immunity in the whole population of greater than or equal to 95%.     

Prevalence of protective antibody against measles in HIV-infected children with immune recovery after highly active antiretroviral therapy

OBJECTIVES: This study was conducted to determine the prevalence of measles-protective antibody in HIV-infected children with immune recovery after highly active antiretroviral therapy (HAART). METHODS: Ninety-six HIV-infected children were enrolled in the study. Their mean age was 9.7+/-2.6 years, 47% were boys, and 47% were in Centers for Disease Control and Prevention (CDC) clinical category C. All participants had been treated with HAART until they achieved a CD4 cell percentage > or =15%. Three children with a history of clinical measles infection were not included in the data analysis. RESULTS: Only 39 out of 93 children (42%) had a measles-protective antibody level, defined as an anti-measles immunoglobulin G (IgG) level > or =320 mIU/mL. There was no significant difference between the groups with and without protective levels of measles antibody in gender, clinical category, age at which HAART was started, duration of severe immune suppression, CD4 cell count and percentage, or plasma HIV RNA level before and after HAART. CONCLUSIONS: We conclude that, despite a history of measles immunization and evidence of immune reconstitution after HAART, many healthy HIV-infected children are still susceptible to measles.     

Measles IgG seroprevalence prior to mass vaccination in Taiwan.

OBJECTIVES: Measles vaccine was licensed for use in Taiwan in 1968 and mass vaccination has been implemented since 1978. Serological surveys were conducted to characterize measles seroepidemiology prior to mass vaccination. METHODS: Measles IgG was quantitatively measured in 1564 serum samples collected from four populations (nationwide, urban, rural, and mountain areas) during 1974-80 with a commercial EIA kit. The nationwide samples covered age groups from 3 months to 19 years, but the other three samples only covered school-aged children. The cut-off value of seropositivity was set at 100 mIU/ml. RESULTS: In the nationwide samples, measles IgG seroprevalence decreased from 50% at 3-5 months to 13% at 6-11 months, then increased rapidly to 55% at 1-1.9 years and reached 98% at 7-7.9 years of age; this was maintained to young adulthood. In all four samples, seroprevalence also reached >97% in individuals >10 years of age. Semiquantitative analysis found that 24%(10/42) of 1-1.9-year-old children but only 4%(1/24) of 15-19-year-old adolescents had low level measles IgG (100-399 mIU/ml). In addition, the distribution of measles IgG level in 1-1.9-year-old children had two peaks at 200-399 and 1600-3199 mIU/ml, whereas only one peak at 1600-3199 mIU/ml had been found in 15-19-year-old adolescents. The median age of measles infection (i.e. 50% seroprevalence) in Taiwan was 1.4 and 2.1 years, respectively, before and after excluding individuals with measles IgG 100-399 mIU/ml that may have resulted from vaccination. CONCLUSIONS: Measles seroepidemiology in Taiwan in the 1970s seemed to be more similar to that in a developing country rather than in an industrialized country, and there was a low median age of infection.     

Predominant influence of environmental determinants on the persistence and avidity maturation of antibody responses to vaccines in infants

BACKGROUND: Immune responses are complex traits influenced by genetic and environmental factors. We previously reported that genetic factors control early antibody responses to vaccines in Gambian infants. For the present study, we evaluated the determinants of the memory phase of immunoglobulin G (IgG) responses. METHODS: Antibody responses to tetanus toxoid (TT), measles vaccines, and environmental antigens (total IgG levels) were measured in 210 Gambian twin pairs recruited at birth. Intrapair correlations for monozygous and dizygous pairs were compared to estimate the environmental and genetic components of variations in response. RESULTS: In contrast to antibody responses measured in infants at age 5 months, 1 month after immunization, no significant contribution of genetic factors to anti-TT antibody and total IgG levels was detected at age 12 months. Genetic factors controlled measles antibody responses in 12-month-old infants, which indicates that the increasing influence of environmental determinants on anti-TT responses was not related to the older age of the children but, rather, to the time elapsed since immunization. Environmental factors also predominantly controlled affinity maturation and the production of high-avidity antibodies to TT. CONCLUSIONS: Genetic determinants control the early phase of the vaccine antibody response in Gambian infants, whereas environmental determinants predominantly influence antibody persistence and avidity maturation.     

Estimate of the cost/benefit ratio of measles vaccination

Among primary health care programs, one of those that has the highest benefit/cost ratio is measles immunization. An estimate of cases, complicated cases and deaths that could have occurred if such immunization program would not have been run, and costs of medical care (hospitalization, physician's visits, medical treatment and rehabilitation), were calculated. Since population at risk has a steady-state given by those who enter -births- and releave it -when they are 15 years old-, if the program did not exist more than 2 million cases and at least 60,000 deaths from measles would have occurred annually. This hypothetical situation is compared with the actual situation of measles in Mexico during the 80's; 1) no more than 100,000 cases could have been estimated to occur in the very extreme case of notifying only one out of 10 cases. 2) The proportions of vaccinated and immune children under five reach 70 percent; this situation has produced 3) a fade out of epidemicity and has increased the critical size of community population for epidemics and doubled the interepidemic interval with the corollary of 4) increasing the average age of infection. The average cost of vaccinating a child was estimated near 1.25 dollars (US). Estimated costs of disease are related to individual losses. Taking into account these factors, benefit/cost ratio of measles immunization in Mexico is, at least, 100:1. Measles transmission patterns in Mexico are discussed since they lead to increase the benefit/cost ratio as compared to countries where the age of infection was put up before the immunization era. To expand investments on measles immunization is recommended.     

A study on measles epidemic in Sukagawa area, Fukushima Prefecture from 2002 to 2003

Measles epidemic occurred in southern part of Fukushima Prefecture from April 2002 to July 2003. Public Iwase hospital in Sukagawa City was the central hospital in the measles epidemic area and 382 patients with measles were admitted to the hospital during the epidemic. Based on clinical records, age distribution, vaccination history, familiar infection and complications were retrospectively investigated. Moreover, the vaccination rates and their calculating methods in the area were compared and the problems on immunization against measles were discussed. As the result, we found that 1) measles epidemic centered on unvaccinated infants, 2) measles was still serious disease with many complications and sometimes fatal, 3) measles was highly infectious and there was no way for prevention except vaccination, 4) the actual condition of measles vaccination was not reflected exactly by the current calculating methods used for the local health reports by the Ministry of Health Labour and Welfare. For the prevention of measles epidemic, it is necessary to know the exact numbers of patients infected with measles and patients deceased due to measles, to calculate precise vaccination rate, and to form the consensus among parents, physicians and administrators to control measles epidemic by the vaccination.