Measles outbreak in a northern Pakistani village: epidemiology and vaccine effectiveness

In the spring of 1990, local community health workers reported a measles outbreak in several partially vaccinated villages in the Punial Valley in northern Pakistan. The authors conducted an investigation in one of these villages to assess vaccine coverage and vaccine efficacy and to describe the patterns of measles outbreaks that prevailed in this community. The results of a survey of the entire village revealed two major gaps in vaccine coverage: the small minority Sunni community and children over 3 years of age. Vaccine efficacy was estimated to range from 73 to 90% but was markedly reduced in children who were vaccinated under 12 months of age. The occurrence of an outbreak in a community in which a relatively new vaccination program is primarily directed at younger children has been predicted by theoretical models of measles dynamics and is consistent with the experience of other vaccination programs in the developing world. These observations suggest that, in some areas of the developing world, the age groups targeted to receive measles vaccinations may need to be broadened to ensure adequate coverage to prevent recurrent outbreaks.     

Prevalence and factors associated with incomplete immunization of children (12–23 months) in Kwabre East District,Ashanti Region,Ghana

Background

Childhood immunization is one of the most cost effective health interventions but its rate has been declining recently in Ghana. Information on immunization coverage and determinants is needed to improve immunization programmes. The objective of this study was to determine the prevalence and factors associated with incomplete immunization of children (12–23 months) in Kwabre East District, Ghana.

Methods

A cross-sectional, community-based survey involving 322 children and their mothers was carried out. Data were collected on socio-demographic characteristics of mothers, childhood immunization history and mothers’ knowledge and practices of immunization using a structured questionnaire. Children were classified as incompletely immunized if they failed to receive at least one of 8 vaccine doses: - one dose of Bacillus Calmette–Guérin (BCG), 3 doses each of pentavalent, 3 doses of polio and one dose of measles per WHO/UNICEF definition. Chi-square and logistic regression analyses were used to identify the factors associated with incomplete immunisation.

Results

The prevalence of incomplete immunization was low (15.5%) suggesting high immunisation coverage but the coverage of the second measles dose, taken at 18 months of age, was the lowest (23.9%). Most of the mothers knew the importance of immunisation (95.7%) and at least one vaccine-preventable disease or symptom (84.9%). Two factors associated with incomplete immunisation in bivariate analyses (community of residence, and mother’s knowledge of number of oral polio vaccines given to children) were no longer significant in a logistic regression model. Compared to children in Aboaso, children in Gyamfi Wonoo (AOR?=?1.81, 95% CI?=?0.80–4.08), Mamponteng (Bonwunu) (AOR?=?0.59, 95% CI?=?0.24–1.48) and Mamponteng (Town) (AOR?=?0.63, 95% CI?=?0.26–1.55) had similar odds of incomplete immunisation. Similarly, mother’s lack of knowledge of the number of doses of polio vaccine given to children had no effect on the odds of incomplete immunisation (AOR?=?0.53, 95% CI?=?0.22–1.26).

Conclusions

Immunization coverage is high in the Kwabre East district but very few children received the second measles dose. None of the maternal and child factors assessed is associated with immunisation coverage. Further research is needed to identify the determinants of immunisation coverage and the reasons for the low uptake of second measles dose in the study area.

     

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 immunization coverage determined by serology and immunization record from children in two Chicago communities

OBJECTIVES: We compared the prevalence of measles immunization determined by serology with the prevalence of measles immunization determined by immunization records, and identified factors predictive of measles immunization among a sample of children from two Chicago communities. METHODS: We collected demographic information and blood specimens from a sample of children aged 12-71 months in two Chicago communities at risk for low measles immunization coverage levels. We collected immunization information from provider records, parent-held records, and the statewide immunization registry. We compared evidence of immunization determined by serology with evidence of immunization from these three sources of immunization records. RESULTS: The sample of children from the two communities had serologic measles immunity levels of 85% and 90%. Significantly fewer children had evidence of immunization by record in both communities (45% and 63%, respectively). CONCLUSIONS: Immunization coverage levels determined using immunization records were significantly lower than immunization coverage determined using serology. A fully populated immunization registry used by all immunization providers could prevent the problems of record loss and scatter.     

Organising for immunization

In the late 1960s, health workers from a mission hospital in rural Zambia began registering children under 14 years old within 30 miles of the hospital (about 3000 children) by incorporating the cooperation of community leaders. They wanted to give every 0-4 year old child a Road to Health card and every 5-14 year old a vaccine record card and to promote the significance of immunization to parents and community leaders. The mission hospital established mobile health units to conduct regular visits in the center of villages. Staff hugh scales from a tree and borrowed a table to conduct the clinic. They kept a good relationship and communication with the community, leading successful education and communication activities. By 1988, many younger mothers were unfamiliar with a measles or whooping cough epidemic so they tended to not have their infants immunized. Epidemics began killing children nationwide, frightening these mothers so they brought their children for immunizations. The medical mission achieved an 85-90% vaccination coverage rate with immunization clinic attendance climbing quickly. 1 mother even walked 30 miles to have her infant injected with the DPT vaccine, but 10 years earlier, she did not bring her children. Further, measles had not reached her area because the immunization level was so high that it stopped the epidemic.     

Measles, immunisation and disease: situation analysis in a resettlement area of northern India

India has a goal of covering all infants with measles immunization between 9-12 months. The present study was conducted in a resettlement area of east Delhi, with a population of nearly one lac, to assess the extent of measles immunization and infection among children aged under three years. All the 21 blocks of the area were covered and 10% households were selected by systematic random sampling from each of the blocks to provide 944 households and 517 under-3 children, who were individually examined by a doctor. Two hundred and eighty one children aged 12 months or above were immunized at or after 9 months giving a coverage of 74.14%. Among the immunized children 7.78% and 8.36% were vaccinated before and after the recommended age-range (9-12 months) respectively. One fifth of the children aged 12 months or above were not immunized against measles at all. Among the surviving under-3 children, no child suffered measles before 6 months but 11.86% of the children had measles between 6-8 months. Six children were vaccinated even after measles episode and seven children had measles even after immunization. Systematic community contact and special attention to resistant and hostile parents is important in order to accomplish 100% coverage. In view of the sizeable proportion of measles infection among the age group of 6-8 months, there is a case for bringing forward the recommended age for measles immunization, if we are to eradicate the disease.     

Factors associated with complete immunization coverage in children aged 12¿23 months in Ambo Woreda, Central Ethiopia

ABSTRACT: BACKGROUND: Vaccination is a proven tool in preventing and eradicating communicable diseases, but a considerable proportion of childhood morbidity and mortality in Ethiopia is due to vaccine preventable diseases. Immunization coverage in many parts of the country remains low despite the efforts to improve the services. In 2005, only 20% of the children were fully vaccinated and about 1 million children were unvaccinated in 2007. The objective of this study was to assess complete immunization coverage and its associated factors among children aged 12-23 months in Ambo woreda. METHODS: A cross-sectional community-based study was conducted in 8 rural and 2 urban kebeles during January- February, 2011. A modified WHO EPI cluster sampling method was used for sample selection. Data on 536 children aged 12-23 months from 536 representative households were collected using trained nurses. The data collectors assessed the vaccination status of the children based on vaccination cards or mother's verbal reports using a pre-tested structured questionnaire through house-to-house visits. Bivariate and multivariate logistic regression analyses were used to assess factors associated with immunization coverage. RESULTS: About 96% of the mothers heard about vaccination and vaccine preventable diseases and 79.5% knew the benefit of immunization. About 36% of children aged 12-23 months were fully vaccinated by card plus recall, but only 27.7% were fully vaccinated by card alone and 23.7% children were unvaccinated. Using multivariate logistic regression models, factors significantly associated with complete immunization were antenatal care follow-up (adjusted odds ratio(AOR=2.4, 95% CI: 1.2- 4.9), being born in the health facility (AOR=2.1, 95% CI: 1.3-3.4), mothers' knowledge about the age at which vaccination begins (AOR= 2.9, 95% CI: 1.9-4.6) and knowledge about the age at which vaccination completes (AOR=4.3, 95% CI: 2.3-8), whereas area of residence and mother's socio-demographic characteristics were not significantly associated with full immunization among children. CONCLUSION: Complete immunization coverage among children aged 12-23 months remains low. Maternal health care utilization and knowledge of mothers about the age at which child begins and finishes vaccination are the main factors associated with complete immunization coverage. It is necessary that, local interventions should be strengthened to raising awareness of the community on the importance of immunization, antenatal care and institutional delivery.     

Principles of measles control

WHO's Expanded Programme on Immunization has significantly helped to reduce global morbidity and mortality from measles. Recently, some African countries with high vaccine coverage levels have reported measles outbreaks in children above the current target age group for immunization. Outbreaks such as these are to be expected, unless close to 100% of the population are immunized with a vaccine which is 100% effective. Success of an immunization programme requires identification of the distribution and ages of susceptible children and reduction of their concentration throughout the community. Priority should be given to urban and densely populated rural areas. In large urban areas, high coverage of infants must be achieved soon after the age at which they lose their maternal antibodies and become susceptible. This will be facilitated by the introduction of high-dose measles vaccines which can be given at 6 months of age. Where measles incidence is increasing among children aged over 2 years, immunization of older children may be considered during contacts with the health care system, or at primary school entry, if this does not divert resources from immunization of younger children. Health workers should be informed of the predicted changes in measles epidemiology following immunization. The collection, analysis and use of data on measles (vaccine coverage, morbidity and mortality) should be improved at all levels of the health care system in order to monitor the immunization programme's overall impact, identify pockets of low coverage, and allow early detection of and response to measles outbreaks.     

兰山区麻疹疫苗强化免疫效果分析

目的：进一步控制兰山区的麻疹疫情。方法：1999年度对该区149 016名8月龄—14岁儿童实施了麻疹疫苗(MV)强化免疫，接种率为97．38％。随后开展了麻疹免疫监测，应用酶联免疫吸附法(EHSA)检测麻疹和风疹IgM抗体，微量血凝抑制试验检测麻疹IgG抗体。结果：强化免疫后麻疹抗体阳转率达100％，GMT从1：5．56上升到1：52．68；经过流行病学观察，强化免疫后麻疹疫情被控制，2a后发病率下降到0．75／10万，麻疹发病数与1999年相比，下降了97．53％。检测79例麻疹疑似病例血清，其中麻疹IgM阳性16例，占20．25％；风疹IgM阳性12例，占15．19％。结论：开展麻疹强化免疫对控制麻疹效果非常显著。     

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.     

应用麻疹发病率估算麻疹疫苗首剂接种率的效果

目的：评价温州市含麻疹成分疫苗（MCV）首剂（MCV1）接种率。方法采用描述性流行病学方法,对温州市2007-2012年报告的麻疹病例分析并对MCV1接种率进行评价。结果温州市2007-2012年麻疹年均发病率为10.46/10万。其中8～83月龄麻疹年均发病率为43.44/10万（占总病例数的42.59％）。13～83月龄儿童MCV1接种率为73.80％（疫苗效力VE＝90％）或84.92％（VE＝95％）;本地、流动儿童MCV1接种率分别为83.25％和69.51％（VE＝90％）或90.86％和82.02％（VE＝95％）,MCV1及时接种率分别为59.48％（VE＝90％）或74.59％（VE ＝95％）。结论温州市MCV1接种率和及时接种率均较低。应加强流动人口管理,提高MV接种率和及时率。     

Why children are not vaccinated against measles: a cross-sectional study in two Nigerian States

Background

Childhood vaccination rates in Nigeria are among the lowest in the world and this affects morbidity and mortality rates. A 2011 mixed methods study in two states in Nigeria examined coverage of measles vaccination and reasons for not vaccinating children.

Methods

A household survey covered a stratified random cluster sample of 180 enumeration areas in Bauchi and Cross River States. Cluster-adjusted bivariate and then multivariate analysis examined associations between measles vaccination and potential determinants among children aged 12-23 months, including household socio-economic status, parental knowledge and attitudes about vaccination, and access to vaccination services. Focus groups of parents in the same sites subsequently discussed the survey findings and gave reasons for non-vaccination. A knowledge to action strategy shared findings with stakeholders, including state government, local governments and communities, to stimulate evidence-based actions to increase vaccination rates.

Results

Interviewers collected data on 2,836 children aged 12-23 months in Cross River and 2,421 children in Bauchi. Mothers reported 81.8% of children in Cross River and 42.0% in Bauchi had received measles vaccine. In both states, children were more likely to receive measles vaccine if their mothers thought immunisation worthwhile, if immunisation was discussed in the home, if their mothers had more education, and if they had a birth certificate. In Bauchi, maternal awareness about immunization, mothers’ involvement in deciding about immunization, and fathers’ education increased the chances of vaccination. In Cross River, children from communities with a government immunisation facility were more likely to have received measles vaccine. Focus groups revealed lack of knowledge and negative attitudes about vaccination, and complaints about having to pay for vaccination. Health planners in both states used the findings to support efforts to increase vaccination rates.

Conclusion

Measles vaccination remains sub-optimal, particularly in Bauchi. Efforts to counter negative perceptions about vaccination and to ensure vaccinations are actually provided free may help to increase vaccination rates. Parents need to be made aware that vaccination should be free, including for children without a birth certificate, and vaccination could be an opportunity for issuing birth certificates. The study provides pointers for state level planning to increase vaccination rates.

     

Factors Influencing Childhood Immunization in Uganda

This paper investigates the factors associated with childhood immunization in Uganda. We used nationally-representative data from Uganda Demographic and Health Survey (UDHS) of 2006. Both bivariate and multivariate approaches were employed in the analysis. The bivariate approach involved generating average percentages of children who were immunized, with analysis of pertinent background characteristics. The multivariate approach involved employing maximum likelihood probit technique and generating marginal effects to ascertain the probability of being immunized, given the same background characteristics. It revealed that slightly over 50% of children in Uganda were fully immunized. Additionally, 89%, 24%, 52%, and 64% received BCG, DPT, polio and measles vaccines respectively. Factors which have a significant association with childhood immunization are: maternal education (especially at post-secondary level), exposure to media, maternal healthcare utilization, maternal age, occupation type, immunization plan, and regional and local peculiarities. Children whose mothers had post-secondary education were twice as likely to be fully immunized compared to their counterparts whose mothers had only primary education (p<0.01). Thus, gender parity in education enhancement efforts is crucial. There is also a need to increase media penetration, maternal healthcare utilization, and to ensure parity across localities and regions.Key words: BCG vaccine, DPT vaccine, Polio vaccine, Full immunization, Measles vaccine, Uganda     

百色市2010年麻疹疫苗强化免疫活动分析

目的 总结分析百色市麻疹疫苗强化免疫活动的数据,为制定"消除麻疹"策略提供依据.方法 对百色市所有8月龄~14岁儿童(包括流动儿童),无论既往有无接种史或患病史,均接种1剂次麻疹疫苗.通过收集整理全市MV强化免疫报表数据和现场评估等情况,采用流行病学方法进行分析.结果 本次强化免疫摸底应种儿童数为699 354人,报告接种人数669 411人,报告接种率为95.72%;麻疹疫苗强化免疫疑似预防接种异常反应报告发生率为2.09/10万;强化免疫后全市尚无麻疹病例报告.结论 麻疹疫苗强化免疫是控制和消除麻疹的有效措施,可迅速提高人群免疫水平,控制麻疹的暴发或流行效果显著.     

UNICEF report highlights unregistered births

This brief article voices a concern about unregistered births and the recent decline in immunization coverage, especially in developing countries. A recent report by UNICEF, "The Progress of Nations, 1998" reports that 1 in 3 newborns, or about 40 million births, are unregistered. Some developing countries lack a registration system. UNICEF is concerned about unregistered births because of the implications for receipt of services. In Kenya, for example, unregistered children may not be eligible for immunization. In the past 20 years, immunization coverage rates have increased from 5% to 80%. This progress may be further improved with the possibility of vaccine coverage for diarrheal diseases and acute respiratory infections. It is predicted that soon it may be possible to save the lives of 8 million children yearly. However, there is a declining trend in immunization at a time when new vaccines are about to enter the market. In addition, 2 million children's lives could be saved if every child were vaccinated. Only 50% of the children in sub-Saharan Africa receive immunization against diphtheria, whooping cough, and tetanus. Measles kills over 800,000 children yearly, but measles immunization is often not performed. Measles immunization varies widely by country in Africa. In Uganda, all children are vaccinated against measles, while only 20% in Kenya are protected against measles. In developed countries, only 89% of children in the US were vaccinated against measles. Adults need vaccination against hepatitis B, which kills about 1 million/year. Yellow fever is reoccurring in Africa and Latin America.     

Early two-dose measles vaccination schedule in Guinea-Bissau: good protection and coverage in infancy.

BACKGROUND: Previous studies from Africa have suggested that there is little benefit to be gained from early two-dose measles vaccination schedules. Two-dose schedules have been associated with no improvement in coverage due to immunization of the same individuals on both occasions, low return rate, high refusal rate, low vaccine efficacy, and fear of blunting of the antibody response. Because of the poor results achieved previously with two-dose measles vaccination schedules, we studied patterns of participation, reasons for non-participation, vaccination coverage and relative efficacy of a one-dose versus a two-dose schedule in connection with the implementation of an early two-dose trial in Guinea-Bissau. METHODS: Children born from September 1994 to January 1996 were randomized into two groups receiving either two doses of measles vaccine at 6 and 9 months or one dose of inactivated polio vaccine (IPV) at 6 months and measles vaccine at 9 months. RESULTS: At 6 months of age 86% (1869/2181) of the children participated, and at 9 months of age participation was 87% (1775/2035). The return rate for obtaining a second dose of vaccine was 93% (1647/1773). The main reason for not participating was travelling (78%). Around 50% of those who did not take part in one vaccination took part in the other. When only children participating the first time they were called for a measles vaccination were included, the measles vaccination coverage in the one-dose group was 59% versus 80% in the two-dose group, i.e. a 50% reduction in the risk of not being vaccinated (relative risk [RR] 0.50; confidence interval [CI]: 0.43-0.57). Few measles cases have occurred in the study area since the implementation of the trial making precise estimation of the relative efficacy of the two vaccine strategies difficult, but all seven clinically diagnosed measles cases occurred in the one-dose group making the relative efficacy for the two-dose group compared with the one-dose group 100% (95% CI: 35%-100%; two-tailed P = 0.016). When including maternal reports, the relative efficacy was 90% (95% exact confidence interval; two-tailed P = 25%-97%, P = 0.022). CONCLUSION: In this study of a two-dose measles immunization schedule at 6 and 9 months of age there was no sign of low participation or poor return rates. The risk of not being vaccinated was lower in the two-dose group than in the one-dose group, and the relative efficacy of a two-dose versus a one-dose schedule was high. Although our results were obtained within a trial where dedicated personnel informed every participant personally about the study, we believe our results indicate that with thorough information about the population it may be possible to achieve a higher coverage with a two-dose measles vaccination schedule than a one-dose schedule. A two-dose schedule may be a feasible way to resolve the problems of low coverage and severe measles infection among infants.     

2006年博白县麻疹疫苗强化免疫情况调查

[目的]分析博白县2006年麻疹疫苗（MV）强化免疫效果,探讨控制麻疹策略。[方法32006年对8月至10岁儿童实施MV强化免疫活动。综合分析MV强化免疫现场调查资料、评估报告、法定传染病报告系统资料。[结果]博白县2006年MV强化免疫共接种目标儿童235782人,报告接种率95．20％,快速评估接种率95．71％,免疫后人群麻疹IgG抗体阳性率为97．54％,保护率达90．16％。[结论]博白县2006年MV强化免疫成效显著。维持高水平常规免疫接种率,适时开展MV强化免疫和后续免疫．是有效控制麻疹的措施。     

Individual level determinants for not receiving immunization,receiving immunization with delay,and being severely underimmunized among rural western Kenyan children

BackgroundEstimating vaccination coverage and delays are important because these measures can identify at risk sub-populations who can be targeted with interventions and public health policies. This paper sought to determine estimates and risk factors for children in rural western Kenya who did not receive immunization, received immunization with delay, or were severely underimmunized.MethodsCaregivers of children aged 12–23 months old were surveyed for immunization history using written records from the immunization booklet. Risk factors for not receiving immunization, delayed immunization, and severe underimmunization were calculated using log-binomial regression. Children were categorized as delayed if a given immunization was received greater than four weeks from the age-appropriate scheduled date. Severely underimmunized children were those who were fully unvaccinated for more than 90 days and had three or more vaccines delayed or not given.ResultsImmunization coverage for pentavalent1, pentavalent3, measles, and fully immunized child (FIC; BCG, three doses of polio, three doses of pentavalent, and measles vaccines) were 99%, 94%, 83%, and 80%, respectively. Approximately, 10%, 24%, and 29%, of children were delayed for pentavalent1, pentavalent3, and measles, respectively. Each model produced a unique combination of risk factors with only advanced maternal age as a risk factor common to all models. Children with delayed receipt of pentavalent1 were at risk for not receiving pentavalent3 (RR: 5.20; 95%CI 3.48, 7.77), measles vaccine (RR: 1.48; 95%CI 1.12, 1.95), and not achieving FIC (RR: 1.88; 95%CI 1.51, 2.34) compared with children who received pentavalent1 on time.ConclusionsImmunization coverage among 12–23 month old children was high, yet a substantial proportion of children were vaccinated with delay. Although vaccine coverage and timeliness are often conceptualized as separate measures, the finding that delayed pentavalent1 receipt was a strong risk factor for not receiving future immunizations indicates the two measures are intertwined.     

2010年玉溪市儿童麻疹强化免疫接种率快速评估

目的评估玉溪市2010年麻疹减毒活疫苗(MV)后续强化免疫效果,总结经验,为控制并加快消除麻疹工作进程制定针对性的免疫策略提供依据。方法每县抽取城区和2个乡镇各30名目标儿童进行现场接种率快速评估。结果全市麻疹疫苗强化免疫接种率为99.66%,不同年龄段麻疹疫苗强化免疫接种率均在99.36%以上;不同居住形式麻疹疫苗强化免疫接种率均在97.78%以上,0剂次免疫史该县及外地的儿童均集中分布于8月龄～2岁年龄组。结论玉溪市2010年麻疹疫苗强化免疫达到了预期的目标。加强流动儿童管理,发现并适时消除免疫空白人群是实现2012年消除麻疹目标的工作重点。     

Measles among under-9-month-olds in rural Bangladesh: its significance for age at immunization

Any decision to modify measles immunization strategies away from the use of the conventional vaccine given to children at 9 months of age to the adoption of recently proposed vaccine strains that can be given to 4-6-month-olds will depend on the age distribution of severe cases of measles in the community. Reported are the results of an analysis of two community-based measles surveillance systems in rural Bangladesh, which found that 17% of all measles cases reported for under-5-year-olds in a nonvaccinated population involved infants aged less than 9 months. In a vaccinated population from the same area, 31% of all measles cases reported for under-5-year-olds occurred among under-9-month-olds. Using a rather restrictive definition for measles-related deaths (those occurring within 6 weeks of the onset of the rash), the proportion of measles-related deaths that occurred before 9 months of age was 13% of all such deaths that were reported.