贵州省1999～2001年脊髓灰质炎疫苗病毒阳性的急性弛缓性麻痹病例流行病学分析

贵州省 1999～ 2 0 0 1年从急性弛缓性麻痹 (AFP)病例粪便标本中分离到脊髓灰质炎 (脊灰 )疫苗病毒 5 3株 ,对其进行了流行病学分析。 5 3例AFP病例分布在全省 8个地区 (州、市 ,下同 )的 31个县 (市、区 ) ,发病时间无明显的聚集趋势。≤ 3岁儿童 4 8例 ,占 90 .6 % ;未免疫和未全程免疫的 38例 ,占 71.7%。其特点是 :全省 9个地区中 8个有病例 ,病例呈散在分布 ;分离出的脊灰疫苗病毒以Ⅱ型为主 (32例 ,占 6 0 .4 % ) ,3年分离的Ⅱ型脊灰疫苗病毒数均超过本年Ⅰ型和Ⅲ型的总和 ;病例中零剂次免疫儿童发病 6 0d后仍残留麻痹的占 82 .4 % ;8例高度怀疑疫苗相关麻痹型脊灰 (VAPP)病例均为 <3岁儿童 ;免疫史为零剂次和 1剂次 ;麻痹时伴发热 ,为不对称麻痹 ,发病 6 0d随访仍残留麻痹并有肌肉萎缩。提示贵州省AFP病例中检出脊灰疫苗病毒的病例 ,集中在 <3岁未免疫和未全程免疫的儿童。因此要高度重视VAPP病例 ,提高和保持高水平的常规免疫覆盖率 ,巩固AFP病例监测质量是保持无脊灰状态、及时发现输入病例和防止疫苗衍生脊灰病毒病例发生的关键。     

安徽省1991～1995年脊髓灰质炎疫情分析

安徽省是我国脊髓灰质炎（脊灰）的高发区之一，自１９９１年建立了脊灰监测系统，实施了消灭脊灰的各项措施以来，脊灰发病率大幅度下降，ｌ９９２～ｌ９９５年连续４年脊灰发病率在０．１／１０万以下。病例散在发生，无季节性发病高峰，并连续４年未发现由脊灰野病毒引起的临床病例。９０％以上的脊灰病例为５岁以下儿童，未服苗及未全程服苗者占６０％。１５岁以下儿童非脊灰ＡＦＰ病例报告发病率１９９４年、１９９５年达到了１／１０万的要求。今后仍应开展强化免疫，重点是流动人口和超计划生育的儿童。     

河南省儿童急性弛缓性麻痹病例残留麻痹影响因素分析

目的 了解河南省急性弛缓性麻痹病例(acute flaccid paralysis,AFP)中残留麻痹儿童的流行病学特征及残留麻痹影响因素.方法 描述性分析河南省2008-2012年394例残留麻痹的年龄＜15岁的AFP病例,用单因素和多因素Logistic回归分析方法分析影响因素.结果 12.88％的AFP病例残留麻痹,年龄＜5岁儿童占73.35％,男女性别比为1.92∶1.肠道病毒分离率为20.81％,病例麻痹部位主要为单下肢、四肢、双下肢.多因素分析结果显示,小年龄麻痹、夏季发病、脊灰疫苗免疫史＜3剂次、肠道病毒阳性、四肢麻痹、报告医院级别高是儿童AFP病例残留麻痹的危险因素.结论 提高脊灰疫苗接种率、养成良好的卫生习惯、尽早对因对症治疗及康复训练,是降低儿童AFP病例残留麻痹率的有效措施.     

西安市2007年急性驰缓性麻痹病例流行病学分析

目的为了进一步掌握西安市急性迟缓性麻痹（AFP）病例流行特征，从而提高AFP病例的监测工作质量。方法根据AFP病例个案调查表和随访表进行统计分析。结果西安市2007年共报告AFP病例22例，15岁以下儿童非脊灰AFP病例报告发病率为2．02／10万。病例分布在全市10个区（县）占76．92％，AFP病例中男女比例为1．75：1，其中1—4岁儿童占发病总数22．73％，未全程免疫占病例总数13．64％，60d后随访残麻率为40．91％，全程免疫残麻率31．58％，未全程免疫残麻率为100．00％，AFP病例粪便标本采集率为90．9％，实验室分离出1例肠道病毒株，未发现有脊灰野病毒病例。结论在进一步提高AFP病例报告的特异性的同时，需对薄弱地区的工作加大力度，消除免疫空白，以确保全市无脊灰病例发生。     

安徽省1993～1997年非脊髓灰质炎急性弛缓性麻痹病例流行病学分析

对安征省１９９３～１９９７年非脊髓灰质炎（脊灰）急性弛缓性麻痹（ＡＦＰ）病例进行了流行病学分析。结果显示，安徽省自１９９４年以来，非脊灰ＡＦＰ病例报告发病率一直在１／１０万以上，１９９３～１９８７年全省有半数的地区、市非脊灰ＡＦＰ病例年平均报告发病率达到１／１０万。非脊灰ＡＦＰ病例构成比，除了病因不明又无残留麻痹和其它非脊灰ＡＦＰ病例（指周期性麻痹、单瘫、肌病等），非脊灰肠道病毒（ＮＰＥＶ）感染、创伤性神经炎和格林巴利综合征（ＧＢＳ）依次为前三位，ＧＢＳ年平均发病率只有０．０８／１０万。非脊灰ＡＦＰ病例主要发生在０～４岁儿童，有明显的季节性分布，男性多于女性。提示我省仍然存在着监测薄弱地区和病例漏报现象，今后应继续加强ＡＦＰ病例监测，尤其在流行季节，并且重点侧重于小年龄儿童；抓好常规免疫，开展强化免疫，重点是流动儿童、超生儿童及偏远地区儿童；继续对临床医生加强培训，提高他们的报病意识及对ＡＦＰ病例的病因诊断能力，提高临监测系统的质量。     

2003年西安市急性驰缓性麻痹病例流行病学分析

2003年西安市共报告本市急性迟缓性麻痹(AFP)病例29例，15岁以下儿童非脊灰AFP病例报告发病率为1．55／10万。病例分布在全市10个区(县)占76．92％，AFP病例中男女比例为1．07：1，其中1～4岁儿童占发病总数46．28％，未全程免疫及免疫不详占病例总数10．34％，60d后随访残麻率为48．28％，全程免疫残麻率46．15％，未全程免疫残麻率为66．67％(X^2=0．453，P＞0．05)，AFP病例粪便标本采集率为89.30%，实验室分离出2例肠道病毒株，未发现有脊灰野病毒病例。     

昭通市1992-2011年脊灰疫苗株病毒病例流行病学分析

目的了解1992-2011年昭通市急性迟缓性麻痹病例中检出脊髓灰质炎疫苗株病毒病例的流行病学特征,为维持无脊灰提供科学依据。方法根据脊灰实验室监测结果,对检出脊灰疫苗株病毒病例进行流行病学分析。结果 581例病例合格标本脊灰疫苗株病毒检出61例,检出率为10.50%;检出疫苗株病毒病例集中在2岁以内儿童,男多于女;未进行疫苗全程免疫的病例多于全程免疫病例,"0"剂次儿童所占比例较大,最多服苗剂次儿童服苗12剂次;麻痹病例中检出Ⅱ、Ⅲ型病毒较多;15岁以下儿童VAPP的发生率为0.62/100万,服苗者VAPP的发生率为0.49/100万。2010年检出1株疫苗变异株病例,变异株为新出现的VDPV病毒。环境脊灰监测从污水与河流中检出疫苗株病毒,检出率为25%。结论脊灰疫苗基础免疫工作存在薄弱环节。必须保持高水平的疫苗接种率,严防VDPV病例产生和VDPV循环引起脊灰暴发或流行。服苗儿童VAPP发生率高于国内文献报道的西安、福建和杭州,低于甘肃、深圳。加强污水的消毒处理严防接触者VAPP的发生。     

黔南州1990～1999年急性弛缓性麻痹病例流行病学分析

黔南州１９９０～１９９９年共报告急性弛缓性麻痹（ＡＦＰ）病例１３６例。按照病毒学分类标准,脊灰野病毒３例,临床符合病例３４例,非脊灰ＡＦＰ病例９９例,自１９９４年以来未发现脊灰野病毒病例。１５岁以下儿童ＡＦＰ病例报告率自１９９５年以来连续保持在１／１０万以上。１３６例ＡＦＰ病例,分布于１２个县市的８３个乡镇,占总乡镇数的３５．３％。ＡＦＰ病例主要发生在０～５岁儿童,男性多于女性。ＡＦＰ病例零剂次免疫占１１．０％,全程免疫占６２．５％。结果显示,我州还存在ＡＦＰ监测薄弱地区和免疫薄弱地区,应继续加强ＡＦＰ病例监测和常规免疫工作。     

2004—2011年内江市急性迟缓性麻痹病例监测

目的了解内江市实现无脊灰目标证实后急性迟缓性麻痹（AFP）病例的流行病学特征及监测系统的运转情况，为改进监测系统的措施提供依据。方法对内江市2004年建立AFP监测系统以来所有急性迟缓性麻痹报告病例进行流行病学分析。结果8年全市共报告急性迟缓性麻痹151例，其中有9例最后诊断为非急性迟缓性麻痹，其余142例均为脊灰排除病例，无脊灰病毒野毒株检出和脊髓灰质炎病例报告。15岁以下儿童AFP年均报告发病率2．00／10万，48h调查率97．9％，14d内双粪便合格采集率90．1％，粪标本7d送达率94．8％，60～75d及时随访率90．1％，均达到卫生部要求。142例AFP病例中，发病无明显季节性，以学龄前儿童好发，病例诊断以格林利巴综合（GBS）征（53．52％）和非脊灰肠道病毒感染（28．17％）最多；完成3次全程免疫的儿童占68．31％，无免疫史和免疫史不详占23．94％。结论内江市2004—2011年继续保持无脊灰状态，AFP监测系统运转良好，但存在一定免疫空白，粪便标本合格采集率、及时随访率有待提高。     

1995年全国急性弛缓性麻痹及脊髓灰质炎的流行病学分析

１９９５年全国脊髓灰质炎（脊灰）报告发病数为１６８例，分布于１５０个县，发病数分别较ｌ９９３年和１９９４年下降了７４％和４５％。ｌ９９５年仅在云南省发现１例缅甸籍脊灰Ⅰ型野病毒病例，全国木发现本土脊灰野病毒病例。这标志着我国已进入消灭脊灰的后期关键阶段，今后进一步加强监测和免疫仍然是我国消灭脊灰工作的重点。１９９３年以来，我国脊灰发病的季节性高峰逐年消失，脊灰发病的聚集性缩小。而急性弛缓性麻痹（ＡＦＰ）病例的发病却呈明显的夏秋季高峰，５～１０月的发病数约占全年病例总数的６７％。ＡＦＰ病例监测的敏感性逐年提高，报告范围逐年扩大，ｌ９９３～ｌ９９５年报告ＡＦＰ病例的县分别占全国总县数的刀％、４５％和的％，全国共有２２２６个县（７８％）在３年内至少报告１例ＡＦＰ病例，约覆盖总人口的８７％，另有６１１个县（２２％）连续３年未报告ＡＦＰ病例，表明我国部分地区的监测工作还存在薄弱环节。１９９４年和１９９５年ＡＦＰ病例口服脊灰疫苗（ＯＰＶ）≥３次的接种率高峰均集中于２～６岁，且均＞８０％，但是＜１岁儿童始终是历年含未免疫儿童数最多的高危人群，ｌ９９５年全国约有６ｌ％＜ｌ岁的儿童服苗≤２次。     

The ghost of polio haunts us once again. The appeal of the scientific community is clear: “Vaccinate your kids today!”

IntroductionIn the summer of 2022, a vaccination campaign for the prevention of poliomyelitis was launched and “The CDC recommend that all children be vaccinated against polio, or poliomyelitis”. The scientific community is on the alert for new cases of polio, which is spreading. Although polio seemed to have been almost completely eradicated throughout the world, the disease has surprisingly reappeared in some Western countries. The risk of international spread of poliovirus remains a Public Health Emergency of International Concern (PHEIC).MethodThe authors reviewed recent polio cases in some western countries which have caused significant public health concern and they underline the meaning and weight of this issue emphasizing the importance of vaccination.DiscussionIn June 2022, the British authorities announced that they had detected traces of a form of polio derived from a vaccine strain in the wastewater of some London boroughs. Although no cases of disease were identified, the British government immediately announced that it was proceeding to reinstate polio vaccination for all children. A few weeks later, on July 18, 2022, the New Jersey Department of Health notified the CDCP of the detection of type-2 poliovirus in an unvaccinated young man in the New York metropolitan area. This case immediately triggered an appeal from the CDCP to get vaccinated and, above all, to vaccinate children.Low vaccination coverage means that the population is constantly at risk of further cases of paralytic poliomyelitis.ConclusionThe appeal to vaccinate children against polio is crucial, as prevention through vaccination is the only defense against the disease. We think that an efficient vaccination campaign can positively influence the process of eliminating the virus. At the same time, however, it demonstrates that simply lowering one's guard can quickly lead to a resurgence of polio cases. Hence, until polio is eradicated, we can be sure that contagion by the wild virus and the risk of vaccine-derived poliovirus will remain possible.     

Epidemiological events surrounding a paralytic case of poliomyelitis in Sweden

A case of clinical poliomyelitis occurred in Sweden in January 1977; it was the first indigenous case in Sweden since 1962. This incident was of particular interest as it provided an opportunity to study the spread of virus in a cluster of unvaccinated persons and in individuals more or less fully vaccinated with inactivated vaccine. The patient excreted wild type 2 virus and the same type was isolated from 25 other individuals, all of whom were close contacts of virus excretors. Among the close contacts, 14 of 20 unvaccinated preschool children were found to excrete virus, but excretion was not found in any of the 7 vaccinated children examined.     

Seroprevalence of poliovirus antibodies among children in a Dominican community--Puerto Rico, 2002

Although the Region of the Americas was certified as polio-free in 1994, an outbreak of paralytic poliomyelitis associated with circulating vaccine-derived poliovirus (cVDPV) occurred during July 2000-July 2001 on the Caribbean island of Hispaniola. A total of 21 cases of paralytic polio associated with type 1 oral poliovirus vaccine (OPV) strain were reported in Haiti and the Dominican Republic (DR). Outbreaks from cVDPV occur among children in communities with low immunity levels to polioviruses and the absence of circulation of wild poliovirus (WPV). The U.S. territory of Puerto Rico (PR), located approximately 72 miles east of DR, has not had a case of paralytic polio since 1974. However, because of its proximity to DR and concerns that visitors and immigrants from DR (who tend to live in a separate community in PR) might not be fully vaccinated against polioviruses, the PR Department of Health (PRDH) and CDC assessed the seroprevalence of poliovirus antibodies among children aged 7-60 months in a predominantly DR community of PR. This report describes the results of that assessment, which indicated high levels of seropositivity for all three poliovirus serotypes. If vaccination rates remain high, the risk for a polio outbreak in this community is low. However, until all threats of poliovirus are eliminated globally, high rates of vaccination among preschool children must be ensured to prevent outbreaks of paralytic polio from any source (e.g., imported WPV, laboratory strains, or cVDPV) in the United States and its territories.     

Poliomyelitis in Japan during the period 1962-68 after the introduction of mass vaccination with Sabin vaccine

After the mass vaccination of children of susceptible age groups in Japan in 1961, the incidence of poliomyelitis decreased markedly. From 1962 to 1968 a total of 659 paralytic cases were officially notified. Detailed investigations of 626 cases reported to the Poliomyelitis Surveillance Committee revealed that only 185 (29.6%) were cases of paralysis clinically typical of poliomyelitis. Tests on 120 of these 185 cases showed that 75 (62.5%) were positive for poliovirus: 45 of these positive cases were temporally associated with the administration of live poliovirus vaccine and 36 had some residual disability. Wild types of poliovirus were rarely isolated. Only 36 vaccine-related cases of poliomyelitis were observed among the total of more than 11 million newborn infants vaccinated with Sabin vaccine in the period 1962-68.     

Community-based evaluation survey of immunizations in Burkina Faso.

A cluster sample survey was conducted in January 1989 in 3 provinces of Burkina Faso to evaluate an immunization programme (based on two contacts, providing inactivated poliomyelitis vaccine plus DPT) that had been launched in 1982-84. The objectives were to estimate neonatal tetanus (NNT) mortality and poliomyelitis prevalence in the study area. The target population (using the same sample of households comprised 2107 live infants born during the preceding year for the NNT survey, and 17,154 children aged 0-9 years for the poliomyelitis survey. The NNT mortality rate was 3.3 per 1000 live births, and the poliomyelitis prevalence rate was 2.8 per 1000 children aged 5-9 years. Dates of onset of poliomyelitis cases among children aged 0-9 years and the numbers of children at risk during the 10-year recall period, reconstituted with demographic indicators taken from standardized life-tables, were used to calculate the incidence rates of poliomyelitis. These rates could be compared in the 5-year period preceding the survey, and showed a decreasing trend consistent with routine surveillance data.     

Paralytic poliomyelitis in children under 6 years in Pondicherry: a community survey.

STUDY OBJECTIVES--To assess the amount of poliomyelitis and its epidemiological features including risk factors. DESIGN--This was a retrospective study of cases of paralytic poliomyelitis among children 0-6 years of age. SETTING--Pondicherry, India, 1983-89. SUBJECTS--A total of 47,960 children aged less than 6 years. MEASUREMENTS AND MAIN RESULTS--In 1989, 469 field workers undertook a door to door survey of children 0-6 years old to identify those with limb paralysis. This was followed by clinical examination to establish the cause, supplemented by case notes held by the Child Development Services. Altogether 203 cases of limb paralysis were identified, 188 of which were judged a result of paralytic poliomyelitis. The prevalence of poliomyelitis in 1989 was 3.9/1000 among children below 6 years of age. There was a male preponderance with a male:female ratio of 1.4:1. The prevalence was least in infants (1/1000) and highest in children aged 2 to 3 years (6.4/1000). The age at onset was less than 12 months in 42% of cases and less than 3 years in 98%. The median age at onset was 13.4 months. Time series analysis showed a high occurrence of cases from May to September between 1983 and 1989. The legs were affected in 97%. About 41% of children had received three doses of oral polio vaccine. There was a history of intramuscular injection, possibly provoking a paralytic attack, in 54% of cases. CONCLUSION--This retrospective community study involving the staff of the Integrated Child Development Services provided valid data about poliomyelitis with little additional cost and minimum training. Because the study covered a whole population of children under 6 years, rather than a sample, the data will help in monitoring and surveillance of poliomyelitis and also in planning strategies for effective control.     

Isolation of highly divergent vaccine strains of polioviruses in Slovakia

April 2003 was the first time in Slovakia, when the vaccine derived poliovirus Type 2 was isolated from waste water sampled from the waste water disposal plant in Vrakun, which collects most waste from Bratislava. The examination in the Regional reference laboratory in Helsinki revealed an almost 15% divergence from the vaccine strain and genetic identity with the Sabine vaccine strain was only 86.6%. Various cases of paralytic poliomyelitis have been published in world literature, caused by mutants = vaccine derived polioviruses (VDPV). Sporadic diseases were described not only in persons who excreted genetically modified vaccine strains, but even examples of epidemic occurrence connected with circulation and transfer of VDPV in non-vaccinated or insufficiently vaccinated population. Epidemiologist of the State Faculty Public Health Institute of Bratislava, the capital of Slovakia immediately accepted measures to strengthen surveillance of poliomyelitis at all levels in order to minimize the risk for the origin of paralytic disease in the population. The world-wide activities aimed at eradication of poliomyelitis may eliminate the wild virus from human community as well as from the environment. It will be difficult to eradicate poliomyelitis completely before the potentially infectious oral vaccine is substituted with inactivated vaccine.     

Poliomyelitis surveillance in the Czech Republic from the start of vaccination to the certification of eradication in the European Region

Poliomyelitis anterior acuta is an acute infectious disease caused by polioviruses of three antigenic types. First epidemics of poliomyelitis emerged at the end of the 19th century. The World Health Organization launched the poliomyelitis eradication program in 1988. The incidence of poliomyelitis in the world decreased from 350,000 cases in 1988 to 1918 cases in 2002 when poliomyelitis eradication was certified in three WHO regions, the European Region (2002), American Region (1994) and West Pacific Region (2000). Systematic clinico-virological surveillance of poliomyelitis has been carried in the Czech Republic since 1961, including annual vaccination campaigns with living OPV vaccine, clinical screening, virological screening of clinical specimens and sewage water (environmental) samples and sera screening within serological surveys mapping the vaccination immunological efficacy. From 1961 to 2003, 21,423 stool specimens of vaccinated healthy children, 62,440 stool specimens of patients, 6250 cerebrospinal fluid specimens and 2100 throat swab specimens were screened. Within the outdoor environment surveillance, 15,460 sewage water samples were analysed. From 1995 to 2003 129 cases of acute flaccid paresis were investigated in children under 15 years of age and 28 stool samples from their contacts were screened. Over the same period, 1280 sewage water samples from refugee camps were analysed. For serological surveys, about 60,000 sera from healthy individuals of all age categories were investigated. No case of paralytic poliomyelitis has been reported and no wild virus has been isolated in the Czech Republic since 1961.     

Comparison of techniques for the estimation of the prevalence of poliomyelitis in developing countries

Although reliable data on the prevalence and trends of paralytic poliomyelitis are necessary for health planning, they are often difficult to obtain in developing countries. Comparisons were made of the cost and the time taken to obtain prevalence rates of residual poliomyelitis paralysis in a single community by (1) a surveillance and reporting system using physicians and other practitioners, (2) a school survey covering grades 1 to 12, (3) annual surveys of grade 1 schoolchildren, and (4) a house-to-house questionnaire survey. These techniques gave poliomyelitis prevalence rates of 3-5 per 1000 school-age children, and poliomyelitis incidence rates of 12-29 per 100 000 population per year. The annual grade 1 school survey was the cheapest and easiest to carry out and appears reliable in areas with a high rate of school enrolment.     

Timeliness of vaccination and its effects on fraction of vaccinated population

Delayed vaccination against childhood diseases may lead to increased mortality and morbidity among children and also affect the fraction of vaccinated population necessary for elimination of a disease. The purpose of this study was to assess the extent of the delay in vaccinations in four countries belonging to Commonwealth of Independent States and to assess how the timeliness of vaccination affects the vaccination coverage. The fraction of children vaccinated with delay was substantial in all the studied countries, and the impact of differences between countries was stronger than individual risk factors assessed in this study. In presence of vaccination delay, up-to-date vaccination is a biased estimator of the fraction of vaccinated population. Age-appropriate vaccination should be taken into account when assessing vaccination coverage.