Priorities in global measles control: report of an outbreak in N'Djamena, Chad.

In N''Djamena, capital of Chad, measles vaccination coverage of 12-23-month-old children fell from 61% in 1990 to 15% in 1993. A community survey of measles after an outbreak in 1993 showed that among children < 5 years of age, the mean monthly attack rate was 37 per 1,000 (95% CI, 32-43) and the mean case fatality rate was 7.4%. Measles incidence was highest (77/1,000/month) in children aged 9-11 months and fell among children > 3 years of age. Incidence rates were high (56/1,000/month) among 6-8-month-old children, but only 3 deaths occurred in this age group. Measles vaccine efficacy, estimated by comparing attack rates in unvaccinated and vaccinated children, was 71% (95% CI, 59-80%). Extrapolation of the results to the city population indicated that an estimated 19,000 cases and > 1,000 measles-associated deaths occurred in 1993. This preventable morbidity and mortality, in a city where coverage was formerly among the highest in Africa, shows the need for sustained global commitment to preventive health care.     

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.     

Public health dispatch: measles epidemic--Majuro Atoll,Republic of the Marshall Islands,July 13-September 13, 2003

During July 13-September 13, 2003, a total of 647 clinically diagnosed measles cases* were reported on Majuro Atoll in the Republic of the Marshall Islands (RMI); this is the first measles outbreak reported in RMI since 1988. An additional 74 suspected measles cases are under investigation. This report describes the clinically diagnosed measles cases and the public health response to stop the epidemic. Of the 647 cases, 15 (2%) are laboratory confirmed, either by serology, polymerase chain reaction, or viral culture. The age of patients ranged from 2 weeks to 43 years (median: 12 years); 479 (74%) patients were aged <20 years. The overall measles incidence on Majuro Atoll (estimated 2003 population: 25,097) is 26 cases per 1,000 population. The incidence is highest among infants aged <1 year (160 per 1,000 population), followed by children aged 1-4 years (40).     

Association between drinking water disinfection and somatic parameters at birth.

We conducted an epidemiological study in Liguria, Italy, on the association between somatic parameters at birth and drinking water disinfection with chlorine dioxide and/or sodium hypochlorite. Over 2 years (1988-1989), 676 births at two public hospitals, one in Genoa (548 cases) and another in Chiavari (128 cases) were examined and data regarding both mother and child were obtained from hospital records. Results indicate a higher frequency of small body length (< or = 49.5 cm) and small cranial circumference (< or = 35 cm) in infants born to mothers who drank water treated with chlorine compounds. In particular, the statistical analysis (by simultaneous variance analysis and Scheffé test) indicated that there may be an association between infants with smaller body length and mothers who drank water treated with chlorine dioxide [adjusted odds radio (OR) = 2.0; 95% CI = 1.2-3.3] or sodium hypoclorite (adjusted OR = 2.3; 95% CI = 1.3-4.2) and between infants with smaller cranial circumference and mothers who drank water treated with chlorine dioxide (adjusted OR = 2.2; 95% CI = 1.4-3.9) or sodium hypochlorite (adjusted OR = 3.5; 95% CI = 2.1-8.5). The presence of neonatal jaundice is almost twice as likely (adjusted OR = 1.7; 95% CI = 1.1-3.1) in infants whose mothers drank water treated with chlorine dioxide.     

菏泽市2005年麻疹监测与控制对策

目的了解菏泽市2005年麻疹监测系统现状，了解麻疹流行病学特征和流行原因。方法根据菏泽市常规传染病报告系统、麻疹疫情专报系统和年度麻疹发病统计表，对2005年麻疹监测与控制结果进行描述流行病学分析。结果2005年共报告麻疹疑似病例442例，较法定传染病报告系统（381例）多16．01％。麻疹疑似病例发病后7d内报告率为91．18％，报告后48h内调查率为87．56％，病例调查完整率为100％，8月龄-7岁儿童有麻疹免疫史者为40．79％。疑似病例血清标本采集率为56．33％。麻疹确诊病例为380例。麻疹发病呈散发和爆发并存的流行模式，部分高发县影响全市麻疹发病水平。麻疹病例主要集中在1～5月份。麻疹发病以学龄前和学龄儿童为主。8月龄～7岁年龄组的病例中，无免疫史和免疫史不详者分别占38．16％、21．05％。结论菏泽市部分地区麻疹疫苗实际接种率不高，是导致麻疹疫情上升的主要原因。应继续加强适龄人群麻疹疫苗的基础免疫，继续落实应急补充免疫的各项技术措施，继续加强麻疹监测与督导工作。     

Sex-specific differences in mortality after high-titre measles immunization in rural Senegal.

Administration of high-titre measles vaccine (Edmonston-Zagreb (EZ) at > 10(5) plaque-forming units (PFU) per dose) before the age of 9 months has been recommended in areas with high measles mortality before the routine age of immunization after 9 months. The study compares the long-term survival after high-titre measles immunization at 5 months of age with that following routine immunization with standard-titre vaccine at 10 months of age. At 5 months of age the high-titre group received Edmonston-Zagreb (EZ-HT, 5 months) or Schwarz (SW-HT, 5 months) at titres > 10(5) PFU per dose, while the standard-titre group received placebo at 5 months of age and < 10(4) PFU per dose of Schwarz vaccine at 10 months (SW-std, 10 months). All the children were followed up to at least 36 months of age. The mortality ratio (MR) for infants in the EZ-HT, 5 months and SW-HT, 5 months groups was 1.32 (P = 0.089) and 1.45 (P = 0.092), respectively, which did not differ significantly from that of recipients of the SW-std, 10 months. The higher MR among recipients of the high-titre vaccines was due to the significantly lower survival among females compared with the females who received SW-std vaccine (EZ-HT, 5 months MR = 1.76, P = 0.013; SW-HT, 5 months MR = 2.14, P = 0.017). For children aged 5-10 months the high-titre measles vaccine did not increase mortality relative to unvaccinated children who had received placebo.     

Outbreak of measles in a teenage school population: the need to immunize susceptible adolescents.

An outbreak of measles occurred in a community school and the surrounding area in Crowborough, East Sussex, UK, from December 1992 to February 1993. There were 96 suspected cases reported: 66 cases among 1673 students at one school and 30 community cases. The majority of suspected cases were in those aged 11-17 (78%), 2 cases occurred in infants < 1 year old and 8 cases in adults aged 18 years or over. Data collected on 60 (91%) of the 66 suspect school cases showed 56 (93%) had an illness which met a case definition of measles. Eighteen had confirmatory IgM measles antibody. Two cases were hospitalized. The local percentage uptake for measles immunization for the school age years affected varied between 64% and 84%. A survey of parents showed that approximately 74% of the students attending the school had a history of measles immunization. The immunization rates reported by parents for children who developed measles was 21%, (29% based on GP records) compared with 77% for those who remained well. Vaccine efficacy was estimated to be 92%. This outbreak, along with others recently reported in older unimmunized children in the UK, reinforces the need for catch-up immunization programmes to reach this susceptible group of adolescents.     

Measles reporting completeness during a community-wide epidemic in inner-city Los Angeles.

A study was undertaken to determine the extent of measles underreporting among preschool-age children. In two community surveys conducted in inner-city Los Angeles during 1990 and 1991, respondents were asked whether preschool-age children in their households had ever been ill with measles. Information about measles episodes was obtained and medical records were reviewed, when available. A probable measles case was defined as having 3 or more days of rash with fever of 38.3 degrees centigrade or greater, and either cough, coryza, or conjunctivitis. To determine the proportion of cases reported, probable measles cases identified were matched with measles cases reported to the Los Angeles County Department of Health Services. Of the 947 children ages 6 weeks through 59 months included in the surveys, 35 children had experienced an illness episode which met the probable measles case definition. Ten (29 percent) of the 35 probable measles cases were reported to the health department. Hospitals reported 9 (69 percent) of 13 probable measles cases evaluated while private physicians'' offices reported 0 (0 percent) of 12 evaluated (Fisher''s exact test, P < 0.001), although 5 children were seen by private physicians before rash onset. Reporting was more complete for cases occurring during 1990 and 1991 (33 percent) than from 1987 through 1989 (18 percent). The hospitalization rate for preschool-age children with probable measles cases in the catchment area was estimated to be 8 percent (95 percent confidence interval = 0 to 18 percent).(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of an early two-dose measles vaccination schedule.

Vaccination at 6 months of age followed by routine revaccination is recommended when exposure of infants to measles is likely. Dade County, Florida, began this early two-dose schedule during a large epidemic in 1986-1987 (i.e., 22% of cases occurred in infants aged 6-11 months). This schedule was continued routinely in high-risk areas. The effect of an early two-dose schedule on measles prevention in the county was examined by comparing measles vaccination coverage and epidemiology before (1985-1987) and after (1988-1996) the schedule became routine. To assess serologic response, seroprevalence of measles antibody among children aged 4-6 years in 1995 was examined. To evaluate vaccine effectiveness, a case-control study was conducted among preschool-aged children. Among those aged 2 years, vaccination coverage with > or =1 dose increased from 75% to 94% in 1996. The number of annual cases declined, and endemic measles transmission reportedly ended after 1993. Seroprevalence of plaque reduction neutralization antibody (titer > 1:120) among those receiving vaccination according to an early two-dose schedule and a single dose at age > or =12 months was 94% (95% confidence interval: 89, 98) and 98% (95% confidence interval: 95, 100). In these groups, vaccine effectiveness was comparably high. Early two-dose measles vaccination is associated with improved coverage and a comparably high level of humoral immunity and clinical protection as a single dose at age > or =12 months. This strategy can be useful in areas at high risk for measles among infants.     

Obstacles in measles elimination: an in-depth description of a measles outbreak in Ghent,Belgium, spring 2011

Background

From Mid-February to April 2011 one of the largest measles-outbreak in Flanders, since the start of the 2-dose vaccination scheme in 1995, took place in Ghent, Belgium. The outbreak started in a day care center, infecting children too young to be vaccinated, after which it spread to anthroposophic schools with a low measles, mumps and rubella vaccination coverage. This report describes the outbreak and evaluates the control measures and interventions.

Methods

Data collection was done through the system of mandatory notification of the public health authority. Vaccination coverage in the schools was assessed by a questionnaire and the electronic immunization database ‘Vaccinnet’. A case was defined as anyone with laboratory confirmed measles or with clinical symptoms and an epidemiological link to a laboratory confirmed case. Towards the end of the outbreak we only sought laboratory confirmation for persons with an atypical clinical presentation or without an epidemiological link. In search for an index patient we determined the measles IgG level of infants from the day care center.

Results

A total of 65 cases were reported of which 31 were laboratory confirmed. Twenty-five were confirmed by PCR and/or IgM. In 6 infants, too young to be vaccinated, only elevated measles IgG levels were found. Most cases (72%) were young children (0–9 years old). All but two cases were completely unimmunized. In the day care center all the infants who were too young to be vaccinated (N=14) were included as cases. Thirteen of them were laboratory confirmed. Eight of these infants were hospitalized with symptoms suspicious for measles. Vaccination coverage in the affected anthroposophic schools was low, 45-49% of the pupils were unvaccinated. We organized vaccination campaigns in the schools and vaccinated 79 persons (25% of those unvaccinated or incompletely vaccinated).

Conclusions

Clustering of unvaccinated persons, in a day care center and in anthroposophic schools, allows for measles outbreaks and is an important obstacle for the elimination of measles. Isolation measures, a vacation period and an immunization campaign limited the spread of measles within the schools but could not prevent further spread among unvaccinated family members. It was necessary to raise clinicians'' awareness of measles since it had become a rare, less known disease and went undiagnosed.     

连云港市1996～2005年麻疹流行病学特征分析

[目的]了解连云港市麻疹流行特征与规律,探讨适合本地区特点的麻疹防治对策与措施。[方法]收集1996～2005年麻疹疫情资料及2004～2005年麻疹监测资料,应用SAS6.12统计软件分析。[结果]1996～2005年共报告568例麻疹病人。局部散在发病,人群以散居儿童和学生为主,占79.9%;发病年龄主要集中在5～9岁组,占总发病人数的28.17%,小于1岁组和成人发病呈上升趋势,病例集中在3～6月份。[结论]连云港市麻疹总发病率得到有效控制,局部仍有散在发病,需要进一步采取针对性有效措施,以达到控制和消除麻疹的目标。     

208例麻疹患者的临床流行病学分析及几点经验教训

目的 从临床工作者的视点探讨深圳１９９８年的麻疹较大流行的特点和临床特点。方法 利用本院收治的２０８例麻疹的资料,分析比较４个年龄段中外来人口和本地人口患者的占有比、≤８月龄患儿的麻疹疫苗接种史和母亲麻疹史、〉８月龄患者中外来人口和本地人口的麻疹疫苗接种史等。结论 （１）〉８月龄的外来人口１０７例中,未种麻疹疫苗者占７９．４％;〉８月龄的本地人口７２例中,未种麻疹疫苗者占４１．７％;（２）发病年龄     

Epidemic cholera among refugees in Malawi,Africa: treatment and transmission.

Between 23 August and 15 December 1990 an epidemic of cholera affected Mozambican refugees in Malawi causing 1931 cases (attack rate = 2.4%); 86% of patients had arrived in Malawi < 3 months before illness onset. There were 68 deaths (case-fatality rate = 3.5%); most deaths (63%) occurred within 24 h of hospital admission which may have indicated delayed presentation to health facilities and inadequate early rehydration. Mortality was higher in children < 4 years old and febrile deaths may have been associated with prolonged i.v. use. Significant risk factors for illness (P < 0.05) in two case-control studies included drinking river water (odds ratio [OR] = 3.0); placing hands into stored household drinking water (OR = 6.0); and among those without adequate firewood to reheat food, eating leftover cooked peas (OR = 8.0). Toxigenic V. cholerae O1, serotype Inaba, was isolated from patients and stored household water. The rapidity with which newly arrived refugees became infected precluded effective use of a cholera vaccine to prevent cases unless vaccination had occurred immediately upon camp arrival. Improved access to treatment and care of paediatric patients, and increased use of oral rehydration therapy, could decrease mortality. Preventing future cholera outbreaks in Africa will depend on interrupting both waterborne and foodborne transmission of this pathogen.     

Measles outbreaks in the Mozambican refugee camps in Malawi: the continued need for an effective vaccine

Between November 1988 and January 1989, measles outbreaks occurred in 11 Mozambican refugee camps in Malawi with five camps principally affected. A total of 1214 cases were reported. Despite the reduction of the age of measles vaccination to six months in 1987, attack rates were highest in children aged 6-9 months (10-26%); rates were also high in the 0-5 month age group (3-21%). The case-fatality rate was high among children less than five years old (15-21%). Children were being inappropriately vaccinated, either being vaccinated at less than six months of age (2-29%) or failing to receive a second dose if vaccinated at six months (0-25%). With vaccine coverage between 66-87%, vaccine efficacy in children less than five years old was estimated to be more than 90% in the camps principally affected. Reduction of the age of vaccination leads to logistical problems in vaccine delivery in refugee situations. These outbreaks again indicate the need to improve vaccine coverage with the existing Schwarz vaccine, and also highlight the urgent need for an effective single dose measles vaccine for children less than nine months of age.     

Risk Factors Associated with a Dengue Fever Outbreak in Islamabad,Pakistan: Case-Control Study

BackgroundOn October 23, 2016, 79 dengue fever cases were reported from the Union Council Tarlai to Federal Disease Surveillance and Response Unit Islamabad. A team was established to investigate the suspected dengue outbreak.ObjectiveThe aim of this study was to determine the extent of the outbreak and identify the possible risk factors.MethodsActive case finding was performed through a house-to-house survey. A case was defined as an acute onset of fever ≥38℃ in a resident of Tarlai from October 2 to November 11, 2016, with a positive dengue virus (nonstructural protein, NS-1) test and any of the two of following signs and symptoms: retroorbital/ocular pain, headache, rash, myalgia, arthralgia, and hemorrhagic manifestations. A structured questionnaire was used to collect data. Age- and sex-matched controls (1:1) were identified from residents in the same area as cases. Blood samples were taken and sent to the National Institute of Health for genotype identification.ResultsDuring the active case search, 145 cases of dengue fever were identified by surveying 928 houses from October 23 to November 11, 2016. The attack rate (AR) was 17.0/10,000. The mean age was 34.4 (SD 14.4) years. More than half of the cases were male (80/145, 55.2%). Among all cases, 29% belonged to the 25-34 years age group and the highest AR was found in the 35-44 years age group (35.6/10,000), followed by the 55-64 years age group (35.5/10,000). All five blood samples tested positive for NS-1 (genotype DENV-2). The most frequent presenting signs/symptoms were fever and headache (both 100%). Stagnant water around houses (odds ratio [OR] 4.86, 95% CI 2.94-8.01; P<.001), presence of flower pots in the home (OR 2.73, 95% CI 1.67-4.45; P<.001), and open water containers (OR 2.24, 95% CI 1.36-3.60; P<.001) showed higher odds among cases. Conversely, use of bed nets (OR 0.44, 95% CI 0.25-0.77; P=.003), insecticidal spray (OR 0.33, 95% CI 0.22-0.55; P<.001), door screens (OR 0.27, 95% CI 0.15-0.46; P<.001), mosquito coil/mat (OR 0.26, 95% CI 0.16-0.44; P<.001), and cleanliness of the house (OR 0.12, 95% CI 0.05-0.26; P<.001) showed significant protective effects.ConclusionsStagnant water acting as breeding grounds for vectors was identified as the probable cause of spread of the dengue outbreak. Establishment of surveillance and an early reporting system along with use of protective measures against the vector are strongly recommended.     

芜湖市2005～2011年婴儿麻疹流行特征及影响因素分析

目的通过对芜湖市2005～2011年婴儿麻疹流行特征分析,了解芜湖市婴儿麻疹流行变化规律,探讨婴儿麻疹的预防控制策略。方法对芜湖市2005—2011年206例婴儿麻疹流行特征进行分析,并对婴儿麻疹可能的影响因素进行分析。结果2005—2011年芜湖市婴儿麻疹年均发病率为147．1／10万,处于全人群麻疹发病第一位。市区婴儿麻疹发病率高于农村地区。以5～8月龄为主,发病高峰为3～5月份。87．86％的婴儿麻疹病例无麻疹疫苗免疫史或免疫史不详,在有麻疹疫苗免疫病例中,52．00％的病例在麻疹疫苗接种后2W内发病,32．00％的病例在麻疹疫苗接种后4W以上发病。孕妇麻疹IgG抗体阳性率46．58％,有71．43％8月龄以上婴儿麻疹病例未及时接种或未接种麻疹疫苗,婴儿麻疹疫苗初免后平均麻疹IgG抗体阴性率为3．57％,麻疹流行强度、麻疹疫苗强化免疫、成人麻疹病例对婴儿麻疹病发病无明显影响。结论婴儿是麻疹高发人群,需进一步加强婴儿麻疹的预防控制工作。     

Initiation of food supplements and stopping of breast-feeding as determinants of weanling shigellosis.

The association between the period elapsed since weaning and the risk of shigellosis was assessed between 1 November 1987 and 30 November 1989 for a cohort of 1085 Bangladeshi children aged < 3 years. The children were followed for 1 month after exposure to Shigella spp. in their residential neighbourhoods, and the 268 who developed microbiologically confirmed (n = 118) or clinically presumptive (n = 150) shigellosis were compared with the 817 control children who did not develop either syndrome. No increase in risk was noted among breast-fed infants who received food supplements within the previous 3 months compared with those who had received supplements for longer (adjusted odds ratio (OR) = 1.2; 95% confidence interval (CI) = 0.4-3.0). However, compared with breast-fed children, non-breast-fed children had an increased risk (adjusted OR = 2.0; 95% CI = 1.3-2.9; P < 0.001), which was largely attributable to a substantially increased risk in the 3 months after stopping breast-feeding (adjusted OR = 6.6; 95% CI = 2.9-14.6; P < 0.001). The early post-cessation risk was equivalent for confirmed and presumptive shigellosis, but was particularly pronounced among the severely malnourished (adjusted OR = 10.2; 95% CI = 3.1-33.3; P < 0.001). This complex temporal pattern of risk highlights the need for precise definitions of weaning to facilitate identification of children at high risk for invasive diarrhoeal syndromes.     

Epidemic measles in an isolated unvaccinated population, India

Between June and September, 1986, an outbreak of measles occurred in Pilkhi Primary Health Centre area (population 56,000) in Tehri Garhwal district, Uttar Pradesh, India. Overall, 1092 cases were identified and 62 died; case-fatality ratio was 5.7%. Illness was restricted primarily to children below 15 years of age; 38% cases were in children under 5 and 58% between 5-14 years of age. To better characterize the outbreak, a survey was conducted in 13 affected villages. The age of the cases ranged from 5 months to 19 years (median = 7.0 years). The age-specific attack rates were 22.4%, 54.5%, 46.2% and 35.3% for children under 1, 1-4, 5-9, 10-14 years of age respectively. In as many as four villages, the attack rate in children below ten was 80% or more. Secondary attack rate among family members was 70%. Overall, 82% of children with measles developed complications which consisted mainly of pneumonia, diarrhoea and dysentery. The age-specific case-fatality ratios in infants and children 1-4 years of age were 23.1% and 11.5% respectively; thereafter the rates tended to decline with increasing age and was higher in females than in males (less than 0.05). Pneumonia which was a complication in 39% of measles cases contributed to 56% of deaths. Traditional beliefs and customs in the area were strong and did not encourage treatment of measles cases. Although a measles vaccination programme has been launched in India since 1985, only 30 districts could be covered during the first year and another 90 during 1986.(ABSTRACT TRUNCATED AT 250 WORDS)