Epidemiology of measles in Taiwan: dynamics of transmission and timeliness of reporting during an epidemic in 1988-9.

We analysed nation-wide reported measles cases during the 1988-9 epidemic and found that longer duration and wider spread were two major characteristics of the outbreak. All the 22 county/city index cases were reported with a delay of > 4 days and 64% were aged 5-14 years. This epidemic occurred mainly among 5-14-year-old school-children (59%), infants under 1 year (19%), and pre-school children (18%). The overall attack rate was 0.63 cases per 10,000 population, with the highest attack rate (7.4 cases per 10,000 population) occurring in infants. Among 280 confirmed cases < 15 months of age, 9-month-old infants (42 cases) had a higher risk of measles and peaked at 10 months (49 cases). This epidemic started in March 1988 among 5-9-year-old children in the northern suburban area, then spread to Taipei City and neighbouring counties or cities. It continued to spread from the northern to southern and western areas during the summer vacation and New Year holidays. Multiple logistic regression analysis showed that the delay of measles reporting was strongly associated with the cases infected early in the epidemic (OR = 6.9, P < 0.001) and reported from teaching hospitals (OR = 2.6, P < 0.001). The reappearance of high attack rates among 5-9-year-old children in the 1985 and 1988-9 measles epidemics in Taiwan indicated the persistence of pockets of susceptible individuals even after mass immunization.     

Measles outbreak in the Republic of the Marshall Islands, 2003

BACKGROUND: Measles is a highly contagious viral infection. Measles transmission can be prevented through high population immunity (>or=95%) achieved by measles vaccination. In the Republic of the Marshall Islands (RMI), no measles cases were reported during 1989-2002; however, a large measles outbreak occurred in 2003. Reported 1-dose measles vaccine coverage among children aged 12-23 months varied widely (52-94%) between 1990 and 2000. METHODS: RMI is a Pacific island nation (1999 population: 50,840). A measles case was defined as fever, rash, and cough, or coryza, or conjunctivitis, in an RMI resident between July 13 and November 7, 2003. A vaccination campaign was used for outbreak control. RESULTS: Of the 826 reported measles cases, 766 (92%) occurred in the capital (Majuro). There were 186 (23%) cases in infants aged <1 year and 309 (37%) of cases in persons aged >or=15 years. The attack rate was highest among infants (Majuro atoll: 213 cases/1,000 infants). Among cases aged 1-14 years, 281 (59%) reported no measles vaccination before July 2003. There were 100 hospitalizations and 3 deaths. The measles H1 genotype was identified. The vaccination campaign resulted in 93% coverage among persons aged 6 months to 40 years. Interpretation Populations without endemic measles transmission can accumulate substantial susceptibility and be at risk for large outbreaks when measles virus is imported. 'Islands' of measles susceptibility may develop in infants, adults, and any groups with low vaccine coverage. To prevent outbreaks, high population immunity must be sustained by maintaining and documenting high vaccine coverage.     

Measles control in Maputo, Mozambique, using a single dose of Schwarz vaccine at age 9 months.

In Maputo city, immunization is available at government health facilities, all contacts being used to vaccinate children. Door-to-door mobilization is conducted to identify eligible children and refer them for immunization. Card-documented measles vaccine coverage, estimated by community surveys, rose from 48% in 1982 to 86% in 1986 and 92% in 1992. The median age at measles vaccination was 10.2 months in 1986 and 9.2 months in 1992. The reported measles incidence rates per 100,000 population fell by 92% from 569 in 1977-78 (pre-vaccination) to 44 in 1990-92, and the reported inpatient measles mortality fell from 19.8 to 0.7 per 100,000. Among children whose age at measles onset was known, the proportion of reported measles cases in children under 9 months of age fell from 2162 (20.3% of 10,636 cases) in 1982-85 to 1695 (17.8% of 9501 cases) in 1986-92. The proportion of cases in children aged > or = 5 years increased from 15.2% to 32.8% in the corresponding periods. The global goals for measles control can be achieved by a single dose of Schwarz vaccine at 9 months of age.     

Role of schools in the transmission of measles in rural Senegal: implications for measles control in developing countries

Patterns of measles transmission at school and at home were studied in 1995 in a rural area of Senegal with a high level of vaccination coverage. Among 209 case children with a median age of 8 years, there were no deaths, although the case fatality ratio has previously been 6-7% in this area. Forty percent of the case children had been vaccinated against measles; the proportion of vaccinated children was higher among secondary cases (47%) than among index cases (33%) (prevalence ratio = 1.36, 95% confidence interval (CI) 1.04-1.76). Vaccinated index cases may have been less infectious than unvaccinated index cases, since they produced fewer clinical cases among exposed children (relative risk = 0.55, 95% CI 0.29-1.04). The secondary attack rate was lower in the schools than in the homes (relative risk = 0.31, 95% CI 0.20-0.49). The school outbreaks were protracted, with 4-5 generations of cases being seen in the two larger schools. Vaccine efficacy was found to be 57% (95% CI -23 to 85) in the schools and 74% (95% CI 62-82) in the residential compounds. Measles infection resulted in a mean of 3.8 days of absenteeism per case, though this did not appear to have an impact on the children's grades. Among the index cases, 56% of children were probably infected by neighbors in the community, and 7% were probably infected at health centers, 13% outside the community, and 24% in one of the three schools which had outbreaks during the epidemic. However, most of the school-related cases occurred at the beginning and therefore contributed to the general propagation of the epidemic. To prevent school outbreaks, it may be necessary to require vaccination prior to school entry and to revaccinate children in individual schools upon detection of cases of measles. Multidose measles vaccination schedules will be necessary to control measles in developing countries.     

龙岩市2009年麻疹减毒活疫苗强化免疫活动效果评价

目的评价龙岩市2009年麻疹减毒活疫苗（MV）强化免疫活动效果。方法对MV强化免疫摸底质量、接种率、人群抗体水平和麻疹监测系统资料进行分析。结果 MV强化免疫共接种8月龄～14岁目标儿童387 998人,报告接种率和调查接种率均〉95%,免疫后人群麻疹抗体阳性率和抗体滴度均显著升高,麻疹发病率较强化免疫前下降了93.98%。结论龙岩市2009年麻疹疫苗强化免疫效果显著,发病率已降至1/100万以下。为保持强化免疫取得的成果,应做好常规免疫和麻疹监测工作,适时开展后续免疫。     

Assessment of measles incidence, measles-related complications and hospitalisations during an outbreak in a southern Italian region

A large measles epidemic occurred in 2002 in Campania, a region of southern Italy with inadequate vaccination coverage. We evaluated the burden of the outbreak in children <15 years of age using different data sources. The measles standardized incidence rate was 5,757/100,000, corresponding to 63,368 estimated cases (95% CI: 59,544--67,373). Measles virus strains were identified as belonging to the D7 genotype. The estimated complication rate was 7.6%. A total of 972 measles hospitalisations were detected, giving a hospitalisation rate of 88.3/100,000. Three deaths occurred. These results show that measles can still represent a serious health threat even in industrialized countries.     

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.     

Measles mortality in the United States 1971-1975.

During 1971-75, an average of 35.4 measles-related deaths were recorded each year; one death for every 1,000 measles cases reported. Measles mortality rate was highest in children under 1 year of age, as was the death-to-case ratio. Mortality rates were higher in non-metropolitan than in metropolitan counties. Measles mortality rates were inversely related to median family income.     

Measles in Vietnamese refugee children in Hong Kong.

From September 1991-January 1992, there was a measles epidemic in an established refugee camp for 7000 Vietnamese 'Boat People' living in Hong Kong. This 16 week outbreak occurred against a backdrop of poor uptake of measles vaccination and overcrowded living conditions. Two hundred and sixty-two children were affected (155 boys, 107 girls); 235 children (89.7 %) were < 2 years old, age range 5-39 months. Children age 6-11 months had the highest crude attack rate (AR) of 54.3%. The highest age specific crude AR was 83.8% in children aged 14 months. Measles complications affected 234 (89.3%) children. Sixty-six children (25.2%) were admitted to hospital. There were two deaths from pneumonia, giving a case fatality rate of 0.76%. Measles control in refugee camps continues to be a public health challenge.     

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.     

Measles vaccination levels of children enrolled in WIC during the 1991 measles epidemic in New York City.

OBJECTIVES: This study assessed measles vaccination rates and risk factors for lack of vaccination among preschool children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (WIC) during the 1991 measles epidemic in New York City. METHODS: Children aged 12 to 59 months presenting for WIC certification between April 1 and September 30, 1991, at six volunteer WIC sites in New York City were surveyed. RESULTS: Of the 6181 children enrolled in the study, measles immunization status was ascertained for 6074 (98%). Overall measles coverage was 86% (95% confidence interval [CI] = +/- 1%) and at least 90% by 21 months of age (95% CI = +/- 1%). Young age of the child, use of a private provider, and Medicaid as a source of health care payment were risk factors for lack of vaccination (P < .001). CONCLUSIONS: During the peak of a measles epidemic, measles immunization rates were more than 80% by 24 months of age in a sample of WIC children. The ease of ascertaining immunization status and the size of the total WIC population underscore the importance of WIC immunization initiatives.     

The epidemiology of measles in a partially vaccinated population in an African city: implications for immunization programs

A large outbreak of measles was reported in Pointe-Noire, Congo, between October 1984 and March 1985. An investigation was conducted to determine the epidemiology of measles in this community in which, in 1985, 54% of the children 12-23 months of age had documented evidence of vaccination against measles. The investigation included hospital and clinic record reviews and a community survey. Measles has been continuously transmitted in Pointe-Noire since at least 1979, with seasonal epidemics. In early 1984, the expected epidemic did not occur, and at least 1,000 measles hospital admissions and 100 measles deaths were prevented. Between October 1984 and March 1985, 1,942 measles cases were hospitalized, of which 306 (15.8%) died. During the epidemic, the proportion of nonpreventable cases (cases occurring before nine months of age) was 17%, reflecting the change in age distribution of measles cases in childhood since the immunization program started in Pointe-Noire in 1982. From the community survey, it was estimated that 13% of all children under age five years acquired measles in Pointe-Noire in 1985. Vaccine efficacy was calculated from community and hospital samples to be between 78% and 87%. Our findings suggest that increasing vaccination coverage levels to well above 50% is necessary to substantially reduce measles morbidity and mortality in African cities.     

Study of incidence of measles and vaccination coverage in Ahmedabad urban slums

Measles incidence and vaccination coverage survey was carried out in Ahmedabad urban slums in February 2000. A total of 3073 children between 9 to 59 months were studied. The incidence rate of measles was 11.2% (95% C.I-10.04-12.36). Measles vaccination coverage was only 59.88%. There was no gender difference in vaccine coverage or measles incidence rate. Diarrhoea was the most common complication observed among both vaccinated and unvaccinated children and it was significantly more among unvaccinated children. Among 1840 vaccinated children only 529 (28.75%) children received vitamin A along with measles vaccination.     

2004-2013年保山市麻疹流行特征及 人群麻疹抗体水平分析

摘要:目的　分析2004-2013年保山市麻疹流行病学特征以及人群麻疹抗体水平,为消除麻疹提供理论依据。方法　收集麻疹网络监测系统数据以及整理历年档案进行描述性流行病学分析。2014年,采用多阶段随机抽样方法抽取我市1 948名人群进行个案调查和采集血标本,用酶联免疫吸附试验检测麻疹抗体。结果　2004-2013年,保山市麻疹病例共 403 例,麻疹平均发病率为1.70/10万,保山市麻疹病例主要集中在7岁以下儿童以及20岁以上农民人群,全市麻疹抗体阳性（≥250）率为94.82%,麻疹抗体保护（≥800）率为 70.12%。8～17月龄阳性率为88.05%、18～23月龄阳性率为97.39%、2～3岁阳性率为95.96%、4～5岁阳性率为94.51%、6～9岁阳性率为97.12%、10～13岁阳性率为96.76%、14～17岁阳性率为96.53%,≥18岁阳性率为91.80%,各年龄组间抗体阳性率差异有统计学意义（χ2＝35.317,P＜0.01）。结论　保山市麻疹疫情近年来有上升趋势,小年龄段儿童以及20岁以上农民人群是高危人群。需重点强化小年龄段儿童以及20岁以上农民人群的麻疹防控措施,防止麻疹疫情发生。     

Incidence and risk factors for Malaria, pneumonia and diarrhea in children under 5 in UNHCR refugee camps: A retrospective study

Background

United Nations High Commissioner for Refugees (UNHCR) refugee camps are located predominantly in rural areas of Africa and Asia in protracted or post-emergency contexts. Recognizing the importance of malaria, pneumonia and diarrheal diseases as major causes of child morbidity and mortality in refugee camps, we analyzed data from the UNHCR Health Information System (HIS) to estimate incidence and risk factors for these diseases in refugee children younger than five years of age.

Methods

Data from 90 UNHCR camps in 16 countries, including morbidity, mortality, health services and refugee health status, were obtained from the UNHCR HIS for the period January 2006 to February 2010. Monthly camp-level data were aggregated to yearly estimates for analysis and stratified by location in Africa (including Yemen) or Asia. Poisson regression models with random effects were constructed to identify factors associated with malaria, pneumonia and diarrheal diseases. Spatial patterns in the incidence of malaria, pneumonia and diarrheal diseases were mapped to identify regional heterogeneities.

Results

Malaria and pneumonia were the two most common causes of mortality, with confirmed malaria and pneumonia each accounting for 20% of child deaths. Suspected and confirmed malaria accounted for 23% of child morbidity and pneumonia accounted for 17% of child morbidity. Diarrheal diseases were the cause of 7% of deaths and 10% of morbidity in children under five. Mean under-five incidence rates across all refugee camps by region were: malaria [Africa 84.7 cases/1000 U5 population/month (95% CI 67.5-102.0), Asia 2.2/1000/month (95% CI 1.4-3.0)]; pneumonia [Africa 59.2/1000/month (95% CI 49.8-68.7), Asia 254.5/1000/month (95% CI 207.1-301.8)]; and diarrheal disease [Africa 35.5/1000/month (95% CI 28.7-42.4), Asia 69.2/1000/month (95% CI 61.0-77.5)]. Measles was infrequent and accounted for a small proportion of child morbidity (503 cases, < 1%) and mortality (6 deaths, < 1%).

Conclusions

As in stable settings, pneumonia and diarrhea are important causes of mortality among refugee children. Malaria remains a significant cause of child mortality in refugee camps in Africa and will need to be addressed as part of regional malaria control and elimination efforts. Little is known of neonatal morbidity and mortality in refugee settings, and neonatal deaths are likely to be under-reported. Global measles control efforts have reduced the incidence of measles among refugee children.     

中国5个县（区）首剂麻疹减毒活疫苗免疫成功率监测分析

目的分析中国5个县（区）儿童接种首剂麻疹减毒活疫苗（First Dose Measles Attenuated Live Vaccine,MV1）后的免疫成功率及受免疫前抗体的影响,评价MV1的接种质量。方法2010年,在黑龙江省富锦县、河北省武安市、广东省广州市海珠区、江苏省响水县和上海市松江区,对290名适龄儿童在接种MV1前和接种后1个月,各采集1次血标本,进行血清抗体检测。结果5个县（区）儿童MV。免疫前麻疹免疫球蛋白（Immunoglobulin,Ig）G平均阳性率为13．28％,免疫后麻疹IgG阳性率为98．34％。8～17月龄儿童麻疹IgG阳性率的差异无统计学意义（x2=0．49,P〉0．05）,仅7月龄组低于其他组;不同月龄组麻疹IgG几何平均浓度的差异有统计学意义（F=2．26,P〈0．05）。MV1免疫后免疫成功率为85．89％,MV1免疫前麻疹IgG阴性者免疫后免疫成功率为97．60％,MV1免疫前麻疹IgG阳性者免疫后免疫成功率为9．38％。MV1免疫前麻疹IgG不同水平的儿童,MV1免疫后麻疹IgG阳性率、阳性者麻疹IgGGMC差异均无统计学意义（X2=2．16,F=1．82;P均〉0．05）,但MV。免疫后免疫成功率差异有统计学意义（x2=178．29,P〈0．05）。结论儿童接种MV1后可使麻疹IgG阳性率达到较高水平;MV1免疫成功率水平较高;5个县（区）儿童的MV1及时接种率有待提高。     

淮北市2004～2007年度麻疹流行病学分析

目的了解淮北市2004～2007年度麻疹流行病学特点，为控制麻疹流行提供依据。方法对2004～2007年度麻疹疫情和监测系统运行情况进行分析。结果2004～2007年度总计报告麻疹疑似病例738例，其中实验室确诊麻疹病例374例。报告确诊病例中本地病例360例，年平均报告发病率4．36／10万。以春季高发，发病年龄以学龄儿童为主，46％的病例麻疹疫苗（MY）免疫史不详，27．8％的病例无MV免疫史。全市麻疹监测系统运转基本正常，敏感性高，麻疹发病率已控制在较低水平。结论为加速控制和消灭麻疹，应提高初始及4周岁复种麻疹疫苗的接种率。     

Measles epidemic in Romania, 1996-1998: assessment of vaccine effectiveness by case-control and cohort studies

A measles epidemic occurred in Romania with 32,915 cases and 21 deaths reported between November 1996 and June 1998, despite high vaccination coverage since the early 1980s. Most cases were unvaccinated children aged <2 years and vaccinated school-aged children. A case-control study among preschool children and a cohort study among primary-school children were conducted to estimate effectiveness of Romanian-produced measles vaccine, and to evaluate age at vaccination and waning immunity as risk factors for vaccine failure. Both studies indicated that measles vaccine was highly effective. One dose reduced the risk for measles by 89% (95% confidence interval (CI) 85, 91); two doses reduced the risk by 96% (95% CI 92, 98). Children vaccinated at <1 year of age were not at increased risk for measles compared with children vaccinated at > or =1 year. Waning immunity was not identified as a risk factor since vaccine effectiveness was similar for children vaccinated 6-8, 9-11, and 12-14 years in the past. Because specific groups were not at risk for vaccine failure, an immunization campaign that targets all school-aged children who lack two doses may be an effective strategy for preventing outbreaks. A mass campaign followed by increased first-dose coverage should provide the population immunity required to interrupt indigenous measles virus transmission in Romania.     

云南省华宁县健康人群麻疹抗体水平分析

目的掌握云南省华宁县健康人群麻疹疫苗接种率和麻疹IgG的抗体水平,探索免疫薄弱环节,为提高该县免疫规划工作提供科学依据。方法采取分层整群抽样方法,在华宁县辖区内随机抽取9个接种点,分8个年龄组（8—17和18—23月龄,2—3、4—5、6—9、10～13、14—17和≥18岁）进行麻疹疫苗接种率调查和麻疹IgG抗体水平检测,每个年龄组40—50人,共检测394人。采用酶联免疫吸附试验检测血清中的麻疹IgG抗体水平。结果调查的394人中麻疹疫苗接种率为85．53％,有效保护率为85．02％,抗体阳性率为98．48％,GMT为1：643;不同接种点麻疹疫苗接种有效保护率、GMT差异有统计学意义（P〈0．01）;各年龄组间麻疹疫苗接种率、抗体阳性率、有效保护率、GMT差异均有统计学意义（P〈0．01）,低龄组相对较低。结论华宁县健康人群麻疹疫苗接种已取得理想的免疫效果,但须进一步提高低龄组婴儿及时接种率,关注流动儿童和大龄儿童,特别是非免疫规划人群的保护。     

Measles antibody levels among vaccinated and unvaccinated children 6–59 months of age in the Democratic Republic of the Congo, 2013–2014

BackgroundMeasles is endemic in the Democratic Republic of the Congo (DRC), and 89–94% herd immunity is required to halt its transmission. Much of the World Health Organization African Region, including the DRC, has vaccination coverage below the 95% level required to eliminate measles, heightening concern of inadequate measles immunity.MethodsWe assessed 6706 children aged 6–59 months whose mothers were selected for interview in the 2013–2014 DRC Demographic and Health Survey. History of measles was obtained by maternal report, and classification of children who had measles was completed using maternal recall and measles immunoglobulin G serostatus obtained from a multiplex chemiluminescent automated immunoassay dried blood spot analysis. A logistic regression model was used to identify associations of covariates with measles and seroprotection, and vaccine effectiveness (VE) was calculated.ResultsOut of our sample, 64% of children were seroprotected. Measles vaccination was associated with protection against measles (OR: 0.15, 95% CI: 0.03, 0.81) when administered to children 12 months of age or older. Vaccination was predictive of seroprotection at all ages. VE was highest (88%) among children 12–24 months of age.ConclusionOur results demonstrated lower than expected seroprotection against measles among vaccinated children. Understanding the factors that affect host immunity to measles will aid in developing more efficient and effective immunization programs in DRC.