小月龄儿疑似脊髓灰质炎疫苗相关麻痹2例流行病学调查

目的：分析2007年及2008年杭州市二例小月龄儿脊髓灰质炎疫苗相关麻痹病例的传播及其影响因素。方法：对报告的2例急性弛缓性麻痹（AFP）患儿进行流行病学调查。结果：1例脊灰病毒分离与定型为Ⅱ＋Ⅲ型,诊断小组认定为脊灰疫苗相关麻痹型脊灰（VAPP）病例。1例实验室检测为阴性,专家诊断小组诊断为可能是VAPP病例,建议按VAPP病例有关规定处理。结论：在实现无脊灰目标后,将面临苗相关麻痹型脊灰病例的发生等问题。应采取的措施主要是：保持高水平的免疫接种率和高质量的急性弛缓性麻痹病例监测工作。     

2004-2013年河南省脊髓灰质炎疫苗 相关麻痹型病例分析

摘要:目的　了解河南省疫苗相关麻痹型脊髓灰质炎（Vaccine-Associated Paralytic Poliomyelitis,VAPP）病例发生情况,为其防控策略制定提供科学依据。方法　对河南省2004-2013年的VAPP病例进行描述性分析。结果　河南省2004-2013年共发生VAPP病例19例,VAPP发生率为0.14/100万,首剂服苗VAPP发生率为0.93/100万。VAPP病例男女性别比为8.5∶1,2～6月龄儿童占73.68%。73.68%的病例为首次服苗,服苗至麻痹平均时间间隔为23 d,随访均有残留麻痹。病例便标本病毒分型以Ⅱ型为主。结论　VAPP病例以低月龄、首次服苗儿童为主。应加强接种前预检工作,严格掌握禁忌症。同时适时调整脊灰疫苗免疫策略,减少或避免VAPP的发生。     

The occurrence of vaccine-associated paralytic poliomyelitis in Brazil, 1995 to 2001]

OBJECTIVE: To describe the occurrence of vaccine-associated paralytic poliomyelitis (VAPP) in Brazil between 1995 and 2001 and to determine the level of risk for this adverse event. METHODS: This retrospective study utilized data from acute flaccid paralysis investigation and notification records from the Ministry of Health in Brazil. Cases were defined as individuals with a diagnosis of acute flaccid paralysis and a positive stool culture or sequelae compatible with poliomyelitis appearing up to 60 days after the beginning of motor impairment. Also included were individuals in any age range who had contact with vaccinated persons between the 4th and 40th day before the onset of the disease and who developed motor impairment between 4 and 85 days after this contact. Risk was calculated as the ratio between the number of cases and the respective number of doses given in a year, according to the National Immunization Program. RESULTS: Ten cases of VAPP were recorded in the period. The mean age of the cases was 4.7 months. Four cases were associated with the first dose, four with the second dose, and two cases were attributed to contact. In two cases type 1 virus was identified; in one case, type 2; and in three cases, type 3. More than one serotype was isolated in four cases. In all 10 cases the serotype was determined. The observed risk for VAPP during the period studied was 1:5.11 million when considering only the first dose and 1:10.67 million for all the doses. CONCLUSION: The main technical and ethical dilemma of the post-poliomyelitis elimination stage is the occurrence of paralytic cases that result from the vaccine policy itself, whose objective is the eradication of polio.     

Risk of vaccine-associated paralytic poliomyelitis in Latin America, 1989-91.

A major factor influencing the success of poliomyelitis eradication in the Americas was the reliance on mass immunization campaigns with oral poliovirus vaccine (OPV). As global poliomyelitis eradication activities accelerate and campaign vaccine delivery strategies are applied elsewhere, it is critical to determine whether the risk of vaccine-associated paralytic poliomyelitis (VAPP) is altered when routine delivery strategies are supplemented with mass immunization campaigns. We analysed all 6043 cases of acute flaccid paralysis (AFP) reported in Latin America over the period 1989-91 in order to estimate the risk of VAPP. The overall risk was estimated to be one case per 1.5-2.2 million doses of OPV administered, compared with one case per 1.4 million doses administered in England and Wales (1985-91) and with one case per 2.5 million net doses distributed in the USA (1980-89). These data suggest that to eradicate poliomyelitis globally, strategies that rely on mass immunization campaigns to supplement routine delivery services, as recommended by WHO, do not appear to alter significantly the risk of VAPP.     

A comprehensive investigation of immunity to poliomyelitis in a developing country

A comprehensive nationwide surveillance program of serologic immunity of two-year-old black children, combined with evaluation of vaccine quality and distribution, was carried out in South Africa during 1983-1984. Sera were randomly collected from urban and rural groups and cluster samples collected from the semi-urban group. The sample represented 0.23% of the total target population. Satisfactory levels of immunity were found in the urban (80%) and semi-urban (71%) groups but a disquietingly low level was found for the rural group (59%). Individual districts in the rural group could be singled out for directed cluster sampling at a later stage. History and documentation of immunization corresponded well to serologic findings and revealed also a fairly substantial level of natural immunization among individuals who, on history, had received no vaccine. Some 95% of random samples of vaccine recalled from the field showed satisfactory levels of potency. An immunity surveillance program such as this is ideally suited and highly cost-effective for developing countries with incomplete immunization to prevent large-scale buildup of immunity deficit. The technique, however, is too insensitive to detect localized community immunity defects.     

Reporting vaccine-associated paralytic poliomyelitis: concordance between the CDC and the National Vaccine Injury Compensation Program.

This paper compares cases of paralytic poliomyelitis reported to the systems operated by the National Vaccine Injury Compensation Program and the Centers for Disease Control and Prevention (CDC) for reporting of adverse events associated with vaccination. Of the 118 cases of vaccine-associated paralytic poliomyelitis determined by either system, 18 were reported initially only to the compensation program, 50 only to the CDC, and 50 to both. The annual incidence of vaccine-associated paralytic poliomyelitis determined from data from both systems varied from 6 to 13 cases (mean = 9.1) a year, with an increase of 1.4 cases a year when initial reports only to the compensation program are included. Thus, the compensation program provides important supplemental incidence data.     

福建省2008-2011年疫苗相关麻痹型脊髓灰质炎发生率及其影响因素研究

儿童服用脊髓灰质炎(脊灰)疫苗(OPV)后有可能发生疫苗相关麻痹型脊灰(VAPP)病例,虽然发生率极低,但随着OPV大量使用,在无脊灰国家和地区,VAPP的重要性日渐凸显,因此对VAPP的发生及其影响因素研究日益重要[1].本研究通过免疫规划监测信息管理系统福建省2008-2011年OPV常规免疫以及历年强化免疫/查漏补种OPV数据估算VAPP发生率,并对2004-2011年急性弛缓性麻痹(AFP)病例监测系统病例资料进行分析,探讨VAPP发生的影响因素.     

Imported vaccine-associated paralytic poliomyelitis--United States, 2005

Paralytic poliomyelitis is rare in the United States because of the success of universal childhood immunization and the Global Polio Eradication Initiative. Poliovirus vaccine was introduced in the 1950s. Since then, the United States has eliminated indigenous wild poliovirus transmission, controlled imported wild poliovirus cases, and, through a vaccine policy change (i.e., from live, attenuated oral polio vaccine [OPV] to inactivated polio vaccine [IPV]), eliminated vaccine-associated paralytic polio (VAPP) cases. The most recent VAPP case occurred in 1999. The primary risk for paralytic polio for U.S. residents is through travel to countries where polio remains endemic or where polio outbreaks are occurring. This report describes the first known occurrence of imported VAPP in an unvaccinated U.S. adult who traveled abroad, where she likely was exposed through contact with an infant recently vaccinated with OPV. This case highlights the previously unrecognized risk for paralytic polio among unvaccinated persons exposed to OPV during travel abroad.     

Comparison of methods for estimating the frequency of paralytic poliomyelitis in developing countries.

Standard reporting systems have proved to be unreliable in estimating the frequency of paralytic poliomyelitis in many developing countries. The effectiveness of three survey methods for estimating the prevalence of lameness attributable to poliomyelitis were compared in the Danfa Health Project district of rural Ghana. Lameness was studied because it is easily identified by inexpensive survey techniques. A postal survey of school headteachers was the least costly and most accurate method, giving a prevalence of lameness attributable to poliomyelitis of 7.2 per 1000 schoolchildren. This method is recommended for countries with an extensive network of primary schools. Medical examinations in a village health survey yielded a prevalence of 4.6 per 1000 children aged 6-15 years. This method was relatively expensive but could be justified if the survey was multipurpose. A question added to the annual district census showed a prevalence of 2.2 per 1000 children, a rate still many times higher than estimates from national statistics. The inclusion of such a question in a census or other national survey entails little additional cost and with more careful questioning results should improve. Repeated surveys can be used to assess the success of poliomyelitis vaccination programmes.     

Clinical presentations of acute paralytic poliomyelitis

The concern about the emerging profile of poliovirus associated morbidity and mortality in the 21st century is legitimate [Paul Y. Clinical presentations of acute paralytic poliomyelitis. Vaccine 2005;23:5283]. Rather than case reports of several thousands, patients number at the most in few thousands. Furthermore, better diagnostic techniques have been offered to those handling patients with clinical syndromes resembling acute flaccid paralysis. Bizarre and unconventional clinical presentations might well be a rule than exception in near future. Furthermore, MRI can be used in the diagnosis of anterior horn infection and would play an important role in diagnosis of poliomyelitis [Kornreich L, Dagan O, Grunebaum M. MRI in acute poliomyelitis. Neuroradiology 1996;38(4):371-2]. Imaging techniques would be important in diagnosis of acute flaccid paralysis.     

Injections and paralytic poliomyelitis in tropical Africa

A case-control study was conducted in Yaoundé, United Republic of Cameroon, to evaluate the hypothesis that intramuscular inoculations predisposed young children to paralysis if they were later exposed to poliomyelitis virus. Thirty-three cases with lower motor neuron disease and 66 neighbourhood controls were studied. Poliovirus was isolated from 39% of the paralytic cases but from only 18% of the comparison group. Controls were more likely to have had serological evidence of previous exposure to all three poliovirus types while most of the paralytic cases had been exposed to a poliovirus for the first time. Two-thirds of the paralytic cases but only 11% of the comparison group had been ill, visited a medical facility, and received multiple injections, primarily with quinine and penicillin, in the month prior to the onset of poliomyelitis. There was a strong temporal relationship between these injections and the onset of paralysis. The increased relative risks (15 and 32, respectively) of paralysis associated with inoculations in the two weeks immediately prior to onset of disease were felt to represent the treatment of symptoms related to poliomyelitis. However, the increased relative risks (13 and 27, respectively) three and four weeks prior to onset were felt to be consistent with the hypothesis that intramuscular injections provoked paralysis. Overestimation of this measure of the effect because of bias in the control group is discussed.     

A new epidemiologic and laboratory classification system for paralytic poliomyelitis cases

An epidemiologic classification of paralytic poliomyelitis cases (ECPPC) has been in use in the United States since 1976. In 1985, this classification system was reviewed because of recent changes in the epidemiology of paralytic poliomyelitis and improved laboratory capability to definitively characterize poliovirus strains. An alternative classification system was devised, the epidemiologic and laboratory classification of paralytic polio cases (ELCPPC), that incorporated virus isolation and strain characterization with epidemiologic information. Reported paralytic poliomyelitis cases for 1980-86 were classified by both the ECPPC and the ELCPPC classification systems. The new ELCPPC system classified 91 per cent of the reported cases as vaccine-associated, while the ECPPC system classified only 71 per cent of the reported cases as vaccine-associated. The proposed classification system provides more specific and useful information particularly concerning vaccine-associated paralytic poliomyelitis.     

Unnecessary injections and paralytic poliomyelitis in India.

The effect of prior injections on the pattern and severity of paralytic poliomyelitis has been examined by a retrospective analysis of case notes from an outpatient pediatric clinic in South India. Of 262 children with acute polio, 176 had received unnecessary injections < 48 h before paralysis and 12 had received diphtheria-pertussis-tetanus or provocative injections. Two children injected in the right arm had paralysis in that limb only. Children with no injections (controls) had an equal chance of paralysis (0.73) in each left and right leg. Children with injections in the right or left gluteus or in both had a 19% greater chance of paralysis in the injected leg(s), whereas uninjected legs had a 31% lower chance of paralysis. Injected leg muscles were weaker than those of control children. Legs of control children were stronger than those with one leg injected and much stronger than those with both injected. More than 96% of the children had at least one leg paralysed. Age and vaccine status did not affect the results of injections. After injections there was greater likelihood of death or lack of recovery of muscle strength. About three-quarters of the children had received unnecessary injections; of these 60% had more severe paralysis and a non-paralytic attack became paralytic in 40%. If oral medicines for fevers and diarrhoea replaced unnecessary injections, the prevalence and severity of paralytic polio would be reduced.     

荆门市一例疫苗相关麻痹型脊髓灰质炎病例调查分析

2007年7月16日湖北省荆门市第一人民医院报告了1例脊髓灰质炎（AFP）病例,同年12月26日由湖北省预防接种异常反应诊断小组确诊为疫苗相关麻痹型脊髓灰质炎病例,现将病例调查结果分析如下。