Assessing the cost-effectiveness of different measles vaccination strategies for children in the Democratic Republic of Congo

IntroductionOne of the goals of the Global Measles and Rubella Strategic Plan is the reduction in global measles mortality, with high measles vaccination coverage as one of its core components. While measles mortality has been reduced more than 79%, the disease remains a major cause of childhood vaccine preventable disease burden globally. Measles immunization requires a two-dose schedule and only countries with strong, stable immunization programs can rely on routine services to deliver the second dose. In the Democratic Republic of Congo (DRC), weak health infrastructure and lack of provision of the second dose of measles vaccine necessitates the use of supplementary immunization activities (SIAs) to administer the second dose.MethodsWe modeled three vaccination strategies using an age-structured SIR (Susceptible-Infectious-Recovered) model to simulate natural measles dynamics along with the effect of immunization. We compared the cost-effectiveness of two different strategies for the second dose of Measles Containing Vaccine (MCV) to one dose of MCV through routine immunization services over a 15-year time period for a hypothetical birth cohort of 3 million children.ResultsCompared to strategy 1 (MCV1 only), strategy 2 (MCV2 by SIA) would prevent a total of 5,808,750 measles cases, 156,836 measles-related deaths and save U.S. $199 million. Compared to strategy 1, strategy 3 (MCV2 by RI) would prevent a total of 13,232,250 measles cases, 166,475 measles-related deaths and save U.S. $408 million.DiscussionVaccination recommendations should be tailored to each country, offering a framework where countries can adapt to local epidemiological and economical circumstances in the context of other health priorities. Our results reflect the synergistic effect of two doses of MCV and demonstrate that the most cost-effective approach to measles vaccination in DRC is to incorporate the second dose of MCV in the RI schedule provided that high enough coverage can be achieved.     

Assessing measles vaccine failure in Tianjin,China

Despite increasing global measles vaccination coverage, progress toward measles elimination has slowed in recent years. In China, children receive a measles-containing vaccine (MCV) at 8 months, 18–24 months, and some urban areas offer a third dose at age 4–6 years. However, substantial measles cases in Tianjin, China, occur among individuals who have received multiple MCV doses. This study describes the vaccination history of measles cases 8 months – 19 years old. Data came from measles cases in Tianjin’s reportable disease surveillance system (2009–2013), and from a case control study (2011–2015). Twenty-nine percent of those in the surveillance dataset and 54.4% of those in the case series received at least one dose of MCV. The minimum and median time-to-diagnosis since vaccination revealed an increase in time since vaccination for incremental doses. Considerable measles cases in Tianjin occur in vaccinated children, and further research is needed to understand the reasons for vaccine failure.     

IgG抗体亲和力试验判定麻疹病例的价值

目的评价麻疹IgG抗体亲和力试验对判定麻疹病例的价值。方法以中国疾病预防控制信息系统2013-2015年天津市麻疹实验室确诊病例和麻疹排除病例为研究对象。回顾性追溯保存的病例血清,开展麻疹IgG抗体亲和力试验,重新对麻疹排除病例进行归类。结果共收集到326例麻疹病例血标本,其中实验室确诊病例267例,排除病例59例,≥20岁病例占92.33%(301/326)。麻疹IgG抗体亲和力试验显示,确诊病例和排除病例中麻疹IgG高亲和力抗体的比例分别为66.95%(158/236)和91.23%(52/57),差异有统计学意义(χ²⁼13.33,P<0.001)。根据判定标准,15.25%(9/59)排除病例被重新判定为麻疹病例,其中8例是高亲和力抗体,有含麻疹成分疫苗(MCV)免疫史,判定为继发性免疫失败病例;1例为低亲和力抗体,有典型的麻疹临床症状,无MCV免疫史。结论麻疹IgG抗体亲和力试验能够提供有参考意义的血清学证据,可以减少麻疹急性期血清学诊断中由于IgM抗体假阴性而造成的错误排除。     

Progress toward measles elimination--Japan, 1999-2008

In 2005, the Regional Committee of the World Health Organization (WHO) Western Pacific Region (WPR) set a target date of 2012 for measles elimination in all WPR member states. In Japan, measles control strategies have included 1) a nationwide public awareness campaign implemented in 2001 to promote timely vaccination with the first dose of measles-containing vaccine (MCV1) administered on or after age 12 months, and 2) a 2-dose MCV schedule with the second dose (MCV2) administered at age 5-6 years, adopted in 2006 in accordance with the recommended WPR measles elimination strategy. However, during 2007-2008, Japan experienced a large measles outbreak, which resulted in exportation of measles cases from Japan into countries where measles elimination had been achieved. This report describes the epidemiology of measles in Japan during 1999--2008 and approval of a National Measles Elimination Plan in December 2007 that includes recommendations for immunization strategies, case-based measles surveillance, and monitoring to ensure elimination of measles by 2012. Measles continues to be endemic in Japan, with most cases occurring in children before school entry, except for 2007 and 2008, when a shift to an older age group was observed. With implementation of the National Measles Elimination Plan, Japan is expected to make progress toward achieving the WPR measles elimination goal.     

Evaluating the population measles susceptibility in Tianjin,China

BackgroundMeasles is a highly infectious illness requiring herd immunity of 95% to interrupt transmission. China has not reached elimination goals despite high vaccination coverage. We estimated the population susceptibility against measles in Tianjin, China and to tailor awareness raising activities in the measles elimination plan.MethodsAge-specific measles seroprevalence was evaluated by Enzyme-Linked Immunosorbent Assay (ELISA) on 12,164 individual aged 0–44 years in 2009–2018. Measles IgG avidity testing was performed to confirm the relationship of the waning immunity after vaccination and secondary vaccination failures (SVF) on 324 confirmed measles cases in 2013–2018.Results11,108 samples (91.32%) tested positive for measles IgG, 239 (1.96%) tested as equivocal and 817 (6.72%) were negative. The age distribution of measles cases in Tianjin followed a U-shaped curve and was highest for those at <8 months and again at 20–39 years which correlated closely with the age distribution of measles susceptibility based on measles IgG antibody status (r = 0.72, P < 0.001). The seropositivity rate and antibody geometric mean concentration (GMC) for the 2018 study population were significantly lower (χ² = 7.45, P = 0.006 and t = 12.01, P < 0.001) compared to 2009. The multivariate stepwise logistic regression analysis showed that age and region were the risk factors for both measles seropositivity rate and GMC after vaccination. The proportion of high avidity cases increased with age, being significantly higher in 75.31% of cases in patients aged 30–34 years (χ² = 18.04, P = 0.003).ConclusionsHigh immunization coverage in children alone will not be adequate to realizing sufficient levels of population herd immunity, particularly given that the potential susceptibility window in adult. Implementation of supplemental immunization activity (SIA) targeted to appropriate group aged 30–34 years is recommended.     

A measles outbreak in a middle school with high vaccination coverage and evidence of prior immunity among cases,Beijing, P.R. China

BackgroundAge-appropriate receipt of ≥2 measles-containing vaccine (MCV) doses has been considered evidence of immunity against measles. Transmission of measles is rarely reported among such persons.MethodsWe report a measles outbreak in a middle school in Beijing that has high coverage with≥2 documented MCV doses. History of previous measles and documentation of MCV receipt were collected for all individuals. Cases were identified by active surveillance and confirmed by laboratory tests. Measles immunoglobulin G (IgG) titers and clinical presentations were obtained for each case.ResultsOf 1331 individuals without a prior history of measles, 1172 (88.1% [95%CI:86.4–91.5%]) and 1078 (81.0% [95%CI:78.9–83.1%]) had age-appropriate receipt of ≥2 MCV doses by domestic and U.S. CDC/ACIP criteria, respectively. Thirteen measles cases occurred in the outbreak. The index case and 3 secondary cases were students. The 9 tertiary cases included 2 teachers and 7 students. All 11 student cases received ≥2 age-appropriate MCV doses by Chinese domestic criteria; 8 were age-appropriately vaccinated by U.S. CDC/ACIP criteria. Measles IgG was detected during the acute phase of measles for all but 2 cases -the first case and 1 tertiary case. Among students with age-appropriate receipt of ≥2 MCV doses, the length of time since the last MCV was significantly associated with risk of measles: for the 1172 students, the risk was 4.6 [OR5.6;95%CI:1.4–22.9] and 5.5 [OR6.5;95%CI:1.4–29.8] times higher when the last MCV dose was 5–9 years and ≥10 years prior, respectively, compared with <5 years prior; for the 1078 students, the risk was 4.1 [OR5.1;95%CI:1.3–20.7] times higher when the last MCV dose was 5–9 years prior compared with <5 years prior.ConclusionsThis is the first report from China showing measles transmission among persons with prior evidence of immunity. Secondary vaccine failure may have played an important role in measles transmission. Further laboratory surveillance is needed to assess the persistence of vaccine-induced immunity of domestically-produced MCV in China.     

安徽省2011―2020年麻疹流行特征及消除麻疹策略探讨

目的 分析2011―2020年安徽省麻疹流行特征,探讨消除麻疹策略。方法 采用描述流行病学方法分析2011―2020年安徽省麻疹流行特征。结果 安徽省2011―2020年共报告麻疹病例8 892例,年均发病率为1.48/10万,整体呈现下降趋势(χ²_趋势=1 794.80,P<0.001)。病例主要集中在2―6月,低发病年份无明显季节聚集性。皖北、皖中和皖南地区年平均发病率分别为1.82/10万、1.12/10万和1.24/10万,差异有统计学意义(χ²=44.95,P<0.001)。病例主要集中在不足2岁和15岁以上人群,占总发病数的90.25%。56.94%的病例无明确含麻疹成分疫苗(measles containing vaccine, MCV)接种史,30.40%的病例接种史不详。758例麻疹病例有基因型鉴定结果,其中737例均为本土H1基因型,16例为疫苗株A基因型,B3基因型2例,D8基因型3例。共报告突发公共卫生事件相关信息5起,暴发疫情76起。结论 2011―2020年安徽省麻疹发病呈现下降趋...     

Study on factors associated with seroprotection after measles vaccination in children of 6–14 years in Eastern China

Measles cases have occurred in individuals with histories of vaccination against the disease in Zhejiang Province, China. The purposes of this study were to determine the seroprevalence of immunoglobulin G (IgG) measles antibodies in vaccinated individuals, to explore the waning kinetics of measles antibody among children after receipt of a measles-containing vaccine, and to define high-risk groups in the population. A seroprevalence survey of measles antibody was conducted with 1900 randomly selected and age-stratified participants aged 6–14 years in Zhejiang province. In our study, seronegative persons accounted for 7.17% of study participants. A case-control study of participants who had received at least one dose of measles-containing vaccine was conducted, with 123 cases of immune failure and 1593 controls with immune success. Multivariate logistic regression analysis showed that age, and number of doses were the influencing factors for measles immunization failure. The older a participant (odds ratio [OR] = 1.164), the more likely that measles vaccine immunity failed. In addition, immune failure was more likely to occur after one dose of MCV than two doses (OR = 0.008) or three doses and more (OR = 0.047). In a univariate logistic regression analysis, we found that immune failure was more likely to occur with MCV vaccination beginning at 8 months than at 9–11 months (OR = 0.562) and the subjects whose registration residence was in other cities in Zhejiang province (OR = 3.527). However, these differences in seropositivity were not significant in the multivariate logistic regression analysis. The exponential regression equation of the attenuation model after measles immunization was y = 884.64e^−0.057x (R² = 0.0521, p < 0.001), and results showed that the measles geometric mean concentration of IgG antibodies was approximately 884.64 mIU/ml after the last MCV vaccination and decreased with time since last vaccination.     

Effect of early measles vaccination on long-term protection: A systematic review

BackgroundIn North America, the first dose of a measles-containing vaccine (MCV1) is administered at ≥12 months of age. However, MCV1 may be given to infants <12 months living in highly endemic areas or traveling to these areas. Although an early dose of MCV1 leads to immediate protection, it remains unclear how this impacts long-term immunity.MethodsThis systematic review and meta-analysis evaluates the impact of MCV1 given at <12 months vs. ≥12 months of age on long-term immunogenicity and vaccine effectiveness, with long-term defined as at least one-year post-vaccination. PubMed, EMBASE, Global Health, Web of Science and Scopus were searched on October 31st, 2019. Studies were included if they included a cohort of infants vaccinated <12 months of age and evaluated long-term immunogenicity, vaccine efficacy, or effectiveness.ResultsA total of 51 texts were identified: 23 reported outcomes related to vaccine effectiveness and 30 to immunogenicity. Infants vaccinated with MCV1 < 12 months of age showed an overall higher risk of measles compared to ≥12 months of age (RR = 3.16, 95% CI: 2.00, 5.01; OR = 2.46, 95% CI: 1.40, 4.32). Risk of measles decreased with increasing age at first vaccination, with those vaccinated with one dose ≥15 months at a lesser risk compared to 12–14 months or <12 months. Measles seroconversion and seropositivity was not affected by age at first vaccination, but antibody levels were significantly lower in the MCV1 < 12-month group (MD = −0.40, 95% CI: −0.71, −0.09).ConclusionLong-term measles seroconversion and seropositivity did not appear to be affected by age at MCV1, while vaccine effectiveness decreased with younger age. There was not enough evidence to look at the effect of age at MCV1 on immune blunting.     

Scheduling of measles vaccination in low-income countries: Projections of a dynamic model

Large-scale vaccination campaigns (SIAs) and improved routine immunization (RI) have greatly reduced measles incidence in low-income countries. However, the interval between SIAs required to maintain these gains over the long term is not clear. We developed a dynamic model of measles transmission to assess measles vaccination strategies in Cambodia, Ghana, India, Morocco, Nigeria, and Uganda. We projected measles cases from 2008 to 2050 under (a) holding SIAs every 2, 4, 6, or 8 years, (b) improvements in first dose routine measles vaccine (MCV1) coverage of 0%, 1%, 3% annually, and (c) introducing MCV2 once MCV1 coverage reaches 70%, 80%, 90%. If MCV1 continues improving, then India and Nigeria could hold SIAs every 4 years without significant probability of large outbreaks, and the other countries every 6–8 years. If RI remains stagnant, India and Nigeria should hold SIAs every 2 years, and the other countries every 4–6 years.     

A population profile of measles susceptibility in Tianjin,China

BackgroundMeasles is a highly infectious illness requiring herd immunity of 95% to interrupt transmission. Measles is targeted for elimination in China, which has not reached elimination goals despite high vaccination coverage. We developed a population profile of measles immunity among residents aged 0–49 years in Tianjin, China.MethodsParticipants were either from community population registers or community immunization records. Measles IgG antibody status was assessed using dried blood spots. We examined the association between measles IgG antibody status and independent variables including urbanicity, sex, vaccination, measles history, and age.Results2818 people were enrolled. The proportion measles IgG negative increased from 50.7% for infants aged 1 month to 98.3% for those aged 7 months. After 8 months, the age of vaccination eligibility, the proportion of infants and children measles IgG negative decreased. Overall, 7.8% of participants 9 months of age or older lacked measles immunity including over 10% of those 20–39 years. Age and vaccination status were significantly associated with measles IgG status in the multivariable model. The odds of positive IgG status were 0.337 times as high for unvaccinated compared to vaccinated (95% CI: 0.217, 0.524).ConclusionsThe proportion of persons in Tianjin, China immune to measles was lower than herd immunity threshold with less than 90% of people aged 20–39 years demonstrating protection. Immunization programs in Tianjin have been successful in vaccinating younger age groups although high immunization coverage in infants and children alone would not provide protective herd immunity, given the large proportion of non-immune adults.     

The effect of immunization on measles incidence in the Democratic Republic of Congo: Results from a model of surveillance data

BackgroundMeasles continues to be a leading cause of vaccine-preventable disease mortality among children under five despite a safe and efficacious vaccine being readily available. While global vaccination coverage has improved tremendously, measles outbreaks persist throughout sub-Saharan Africa. Since 2010, the Democratic Republic of Congo (DRC) has seen a resurgence of measles outbreaks affecting all 11 provinces. These outbreaks are mainly attributed to gaps in routine immunization (RI) coverage compounded with missed supplementary immunization activities (SIAs). We utilized national passive surveillance data from DRC's Integrated Disease Surveillance and Response (IDSR) system to estimate the effect of immunization on measles incidence in DRC.MethodsWe investigated the decline in measles incidence post-immunization with one dose of measles containing vaccine (MCV1) with and without the addition of supplementary immunization activities (SIAs) and outbreak response immunization (ORI) campaigns. Measles case counts by health zone were obtained from the IDSR system between January 1, 2010 and December 31, 2013. The impact of measles immunization was modeled using a random effects multi-level model for count data with RI coverage levels and mass campaign activities from one year prior.ResultsThe presence of an SIA (aIRR [95% CI] 0.86 [0.60–1.25]) and ORI (0.28 [0.20–0.39]) in the year prior were both associated with a decrease in measles incidence. When interaction terms were included, our results suggested that the high levels of MCV1 reported in the year prior and the presence of either mass campaign was associated with a decrease in measles incidence.ConclusionsOur results highlight the importance of a two-dose measles vaccine schedule and the need for a strong routine immunization program coupled with frequent SIAs. Repeated occurrences of large-scale outbreaks in DRC suggest that vaccination coverage rates are grossly overestimated and signify the importance of the evaluation and modification of measles prevention and control strategies.     

Estimating the number of US children susceptible to measles resulting from COVID-19-related vaccination coverage declines

Measles elimination hinges on vaccination coverage remaining above 95% to retain sufficient community protection. Recent declines in routine measles vaccinations due to the COVID-19 pandemic coupled with prior models indicating the country was close to the 92% herd immunity benchmark are a cause for concern. We evaluated population-level measles susceptibility in the US, including sensitivity analyses accounting for pandemic-related impacts on immunization. We estimated the number of children aged 0–18 currently susceptible to measles and modeled susceptibility proportions in decreased vaccination scenarios. Participants were respondents to the NIS-Teen survey between 2008 and 2017 that also had provider-verified vaccination documentation. The exposure of interest was vaccination with a measles-containing vaccine (MCV), and the age at which they were vaccinated for all doses given. Using age at vaccination, we estimated age-based probabilities of vaccination and modeled population levels of MCV immunization and immunity vs. susceptibility. Currently, 9,145,026 children (13.1%) are estimated to be susceptible to measles. With pandemic level vaccination rates, 15,165,221 children (21.7%) will be susceptible to measles if no attempt at catch-up is made, or 9,454,436 children (13.5%) if catch-up vaccinations mitigate the decline by 2–3%. Models based on increased vaccine hesitancy also show increased susceptibility at national levels, with a 10% increase in hesitancy nationally resulting in 14,925,481 children (21.37%) susceptible to measles, irrespective of pandemic vaccination levels. Current levels of measles immunity remain below herd immunity thresholds. If pandemic-era reductions in childhood immunization are not rectified, population-level immunity to measles is likely to decline further.     

Measles outbreaks and progress toward measles preelimination --- African region, 2009-2010

In 2008, the World Health Organization (WHO) African Region (AFR) measles technical advisory group (TAG) recommended establishing a measles preelimination goal, to be achieved by the end of 2012. The goal sets the following targets for the 46 AFR countries: ≥98% reduction in estimated regional measles mortality compared with 2000; measles incidence of <5 cases per 1 million population per year nationally; >90% national measles-containing vaccine (MCV) first dose (MCV1) coverage and >80% MCV1 coverage in all districts; and ≥95% MCV coverage by supplementary immunization activities (SIAs) in all districts. The goal also sets surveillance performance targets of ≥2 cases of nonmeasles febrile rash illness per 100,000 population, ≥1 suspected measles cases investigated with blood specimens in ≥80% of districts, and routine reporting from all districts. In addition, introduction of a routine second MCV dose (MCV2) was recommended for countries meeting specific criteria for MCV1 coverage and measles surveillance. This report updates progress toward the preelimination goal during 2009--2010 and summarizes measles outbreaks occurring in AFR countries since 2008. Of the 46 AFR countries, 12 (26%) reported measles incidence of <5 cases per 1 million population during 2010, compared with 28 (61%) in 2008. Furthermore, 28 (61%) countries reported a laboratory-confirmed measles outbreak during 2009--2010. The recent measles outbreaks highlight the need for renewed dedication by donors and governments to ensure that national multiyear vaccination plans, national budgetary line items, and financial commitments exist for routine immunization services and measles control activities.     

中山市2005―2018年麻疹流行特征及含麻疹成分疫苗接种分析

  目的   分析中山市麻疹流行病学特征,评价含麻疹成分疫苗（measles containing vaccine,MCV）保护效果（vaccine effectiveness,VE）。   方法   采用描述性流行病学方法分析中山市2005―2018年麻疹发病资料,采用病例对照研究评价MCV的VE。健康儿童MCV接种资料来源于2017年、2018年中山市疫苗接种率现场调查。   结果   中山市2005―2018年共报告麻疹6 516例,发病率为0.5/10万（2017年）~63.7/10万（2005年）,年均发病率为15.4/10万。4―9月为发病高峰,男、女性别比为1.4:1,职业以散居儿童为主（59.4%）,8月龄~10岁病例中77.4%无MCV免疫史。2017年、2018年中山市儿童MCV接种率分别为97.6%和98.4%,首剂及时接种率分别为65.2%和58.0%。1~10岁儿童接种1剂、2剂MCV的VE分别为93%（95%CI:89%~96%）、96%（95%CI:93%~98%）。   结论   2005―2018年中山市麻疹发病下降趋势明显,近年保持低发态势,但未阻断传播。应继续加强麻疹监测,维持高水平MCV接种率和首剂及时接种率,最终达到消除麻疹的目标。     

African-American children are at risk of a measles outbreak in an inner-city community of Chicago, 2000

BACKGROUND: Since the measles resurgence of 1989-1991, which affected predominantly inner-city preschoolers, national vaccination rates have risen to record-high levels, but rates among inner-city, preschool-aged, African-American children lag behind national rates. The threat of measles importations from abroad exists and may be particularly important in large U.S. cities. To stop epidemic transmission, measles vaccination coverage should be at least 80%. OBJECTIVE: To determine measles vaccination rates and predictors for having received a dose of measles-containing vaccine by age 19 to 35 months among children in an inner-city community of Chicago.METHODS: We used a cross-sectional survey with probability proportional to size cluster sampling. Immunization histories from parent-held records and providers were combined to establish a complete vaccination history. RESULTS: A total of 2545 households were contacted, and 170 included a resident child aged 12 to 35 months. Of these, 97% (N=165 children) agreed to participate. Immunization history from a parent or provider was not available for 20 children. Among children aged 19 to 35 months with available immunization histories, 74% received measles vaccine (n=100); of these, 84% received the vaccine as recommended at ages 12 to 15 months. However, when including children without immunization histories, measles coverage levels among children aged 19 to 35 months were 64% (n=114). Among children with records, predictors for receipt of measles vaccine by age 19 to 35 months were possessing a hand-held immunization card (odds ratio [OR]=16.8; 95% confidence interval [CI]=4.2-67.1); utilizing a public health department provider for a usual source of care (OR=8.9; 95% CI=1.6-47.2); and being up-to-date for vaccines at 3 months of age (OR=5.0; 95% CI=1.8-14.1). CONCLUSIONS: Optimistically assuming that children without immunization histories are as well immunized as children with immunization histories, the measles vaccination rate among Englewood's children aged 19 to 35 months is too low to maintain immunity (74%). Measles coverage levels lagged behind coverage reported in a national survey in Chicago (86%) and the nation as a whole (92%). Efforts to raise and sustain coverage should be undertaken.     

陕西省麻疹高接种率和高发病率的原因分析

目的探讨陕西省麻疹高接种率下高发病率的病原学和疫苗免疫相关因素。方法分析麻疹病例年龄及免疫史。从咽拭子中分离病毒，用酚-氯仿抽提法提取病毒RNA，逆转录一聚合酶链反应（RT—PCR）扩增N基因-COOH端的450个核苷酸（bp）片段，进行序列测定和基因分型。用微量中和试验测定疫苗免疫血清及麻疹病例急性期血清中和疫苗株和野毒株的抗体水平。结果麻疹病例中有麻疹疫苗免疫史的平均占38．97％；麻疹病例急性期血清：有免疫史的中和S191株GMT（56．18）明显高于H1野毒株GMT（26．90）；无免疫史的S191株GMT（25．40）与H1野毒株（27．86）相近。疫苗免疫血清：S191株抗体效价≤16血清中有19．15％为H1野毒株抗体阴性。结论陕西省近年出现的麻疹高接种率水平下的高发病率现象不排除麻疹流行株变异和疫苗对流行株H1基因组野毒株保护性不足两方面因素。     

合肥市适龄儿童麻疹疫苗强化免疫效果评价

目的了解合肥市适龄儿童麻疹疫苗(MV)强化免疫活动(SIA)效果及影响因素,为调整和实施消除麻疹策略提供参考。方法应用分层随机抽样法,选择合肥市社区疫苗接种门诊、幼儿园、小学、中学等作为研究点,分析8月龄～14岁儿童SIA前后麻疹抗体水平。SIA前后分别调查儿童340名和348名,应用描述统计方法,分析SIA前后麻疹流行状况。结果合肥市适龄儿童MV总体接种率为98.04%。SIA后麻疹抗体阳性率、几何平均滴度(GMT)均上升,麻疹抗体阳性率为91.38%。1～4岁组、≥3次免疫史者GMT分别为最高,Logistic多元回归分析显示,1次免疫史者抗体保护水平低。2010年麻疹发病率为0.81/10万,较2009年下降91.86%,发病年龄以婴儿为主,≥2次免疫史者病例构成比最低。结论在麻疹逐渐减弱流行阶段,需要规范适龄儿童首剂次、2剂次MV常规免疫,开展必要强化免疫,加强免疫规划和病例监测质量管理。     

2011 - 2017年湘西自治州麻疹流行病学特征分析

目的 分析2011 - 2017年湘西自治州麻疹流行病学特征。方法 通过中国麻疹信息报告管理系统收集湘西自治州麻疹病例个案的调查数据,采用描述性流行病学方法分析。结果 2011 - 2017年湘西自治州共报告麻疹病例288例,年均发病率1.58/10万;麻疹发病以3 - 6月为发病高峰期;病例以5岁内小年龄的散居儿童为主（85.07%）,尤其以2岁内居多,＜8月龄内儿童及20岁以上成人也占较大比例（35.42%）;男女性别比为1.72∶1;72.83%的8月龄～14岁发病者为含麻疹成分疫苗（MCV）免疫史无或不详; 61.27%的病例出疹前7～21 d有医疗机构就诊或住院史。结论 湘西自治州麻疹发病率呈低发态势,需提高适龄儿童MCV接种率和及时接种率,加强监测和有效处置麻疹疫情,严防院内交叉感染,最终达到消除麻疹目标。