摘要
目的:描述中国人感染高致病性禽流感监测系统(包括不明原因肺炎监测系统、人禽流感应急监测系统)的运行现状;分析监测系统设置的可行性、合理性、现有监测系统与监测目是否匹配等当前存在的主要问题;针对发现的主要问题,提出改进监测系统、提高监测效率的建议;采用WHO和美国CDC推荐的疾病监测系统评价方法,探索适合我国实际的传染病监测系统评价手段,为我国监测系统评价提供经验。
方法:根据《中国人感染高致病性禽流感疫情监测系统评估方案》选点原则,选择重庆市、广州市、湖南省、江苏省为4个评估点,其中湖南省选择5个省辖市、5个市辖县(区),江苏省选择4个省辖市、4个市辖县(区),重庆市和广州市分别选择4个市辖区作为评估点。在每个评估点选择相应的卫生行政部门、疾控机构及1所综合性医疗机构为评估对象。采用统一的调查问卷和访谈提纲对评估对象进行现场问卷调查和深入访谈,内容包括人禽流感监测系统方案设计及运行现状、监测的经费支持、病例诊断与报告、实验室检测、培训督导、存在问题与影响因素等方面,此外,在各省市评估点选择一所综合性医院,对2006年所有住院肺炎/ARDS病例进行回顾性个案调查,包括临床表现、流行病学史、诊断治疗情况等。对所有问卷、访谈、个案调查信息进行统计分析。
结果:
1.基本信息:4个省(市)共有县级以上医疗机构1,992家,均开展“不明原因肺炎病例”监测,仅1.6%(32/1992)的医疗机构报告过不明原因肺炎病例。本次共完成了行政部门相关人员40人的访谈;完成30家疾控部门79人的问卷调查(访谈其中68人);完成30家医疗机构65人的问卷调查(访谈其中58人)。
2.医疗机构监测系统运行现状及相关因素调查:调查的30家医疗机构发现不明原因肺炎病例后,20%的医院会直接网络直报;66.7%的医院认为开展监测增加了工作量、56.7%认为会影响正常的工作秩序;问卷调查的65名对象中,41.54%认为不明原因肺炎病例定义不容易判定,三级医院与二级医院之间差异无统计学意义(X~2=0.39,P>0.5);实际工作中,如果发现可疑不明原因肺炎病例,98.5%认为有必要询问流行病学史及应该采集标本送疾控中心检测。访谈的58名医务人员,分别有58.6%、84.5%认为病例定义合适、简单,三级与二级医院人员间三者差异均无统计学意义(X~2分别为0.59、0.08,P均大于0.1)。
3.疾控机构监测系统运行现状及相关因素调查:调查的30家疾控机构中,60%曾接到并参与了不明原因肺炎病例的报告和处理;调查的79名对象中,93.7%认为可以实现“及时发现、控制人禽流感”的目的、59.5%认为可实现“了解不明原因肺炎报告病例数的动态变化”的目的;89.9%认为人禽流感应急监测可达到“早发现、早报告病例“的目的,但省、市、县三级之间目的可达性之间差异有统计学意义(X~2=7.25,P=0.03);认为县、市级专家组难以作出“‘不明原因肺炎'明确或排除诊断”的比例分别为59.5%、30.4%,县级与市级之间差异有统计学意义(X~2=13.45,P=0.00)。访谈的65名对象中,63.8%认为不明原因肺炎报告不真实;40%认为不容易判定监测病例定义。
4、卫生行政部门访谈:访谈的40名对象中,82.5%认为目前不明原因肺炎病例的排查程序在实际工作中可以有效实施,省、市、县三级之间差异无统计学意义(X~2=0.42,P=0.81);67.5%认为排查机制可操作性好、17.5%认为一般、7.5%认为差,省、市、县三级之间差异无统计学意义(X~2=1.52,P=0.47);对于病例网络报告请示,65%不会同意,省、市、县三级之间差异无统计学意义(X~2=0.55,P=0.76)。
5、住院肺炎回顾性调查:2006年,4个三级医院共有住院病例119,938例,肺炎及肺部急性感染相关病例共4,888例,占住院总数的4.08%;其中肺部感染(未特指)818例,占急性感染相关病例的16.73%,肺炎(未特指)921例,占急性感染相关病例的18.84%。4个二级医院共有住院病例70,130例,肺炎及肺部急性感染相关病例共4,782例,占住院总数的6.82%;其中肺部感染(未特指)551例,占急性感染相关病例的11.31%,肺炎(未特指)377例,占急性感染相关病例的7.88%。共调查符合要求的病例2283例,发现符合不明原因肺炎监测病例定义标准的37例,占调查病例的1.62%,占肺炎及肺部急性感染相关病例的3.74‰,占总住院病例的1.95/万。
6不明原因肺炎病例和人禽流感调查:2004年4月开展不明原因肺炎监测以来,至2007年3月9日,全国共报告不明原因肺炎病例427例,其中22例确诊为人禽流感病例,占5.2%。
结论和建议:
该监测系统自建立以来,我国目前发现的24例(不包括追溯的2003年病例)人禽流感确诊病例都是“不明原因肺炎病例”监测中发现、报告并确诊的,由此可见该监测系统在人禽流感病例的发现、报告、诊断中发挥了很大作用。但是,也存在一定的不足:病例定义缺乏科学性,医务人员对监测定义理解不够,人禽流感应急监测的内容和范围要求过高,排查机制过于复杂,监测针对性太强,报告和处理的压力过大,基层疾控机构、医疗机构的检测能力低下,相关管理制度不完善,经费等保障不落实,宣传不到位等,导致监测结果不能反映真实情况,难以达到监测目的,监测系统的简单性、可接受性有待进一步提高。
建议:修订监测方案,在病例定义中增加可疑流行病学史;加强培训和督导;应急监测根据动物或人间疫情实际发生情况,结合流行病学调查分析,因地制宜制定监测实施方案;取消地市级以上专家组的排查,只需要医院专家组及区县级专家组会诊排查,必要时可请地市或省级专家组会诊,但这绝不是必须的程序;各级政府、部门工作要“以人为本”,尊重科学,尊重事实,不过度反应,不科学的干预;提高实验室的检测能力,研发快速诊断试剂,用于基层初筛;建立不明原因肺炎病例监测报告奖惩制度,专家会诊排查制度及劳务补助制度,体现以人为本的精神;建立国家及地方不明原因监测配套经费,保证经费充足,确保监测顺利进行;加大健康教育、宣传工作。
objectives: To describe the current situation about surveillance system of Highly pathogenic avian influenza virus infection in China, including pneumonia of unknown reason and human avian influenza emergency prepairedness. To analyze whether the surveillance system is feasible and appropriate, and wether the current system matches the surveillance purpose. To make recommendations, based on the major problems identified, for improving the system and enhancing the surveillance efficiency; Standardized disease surveillance evaluation approaches proposed by WHO and US CDC were adopted to explore the locally feasible evaluation methods of highly pathogenic avian influenza virus infection in China , meanwhile, to provide the scientific evidence for the evaluation of other surveillance systems.
[Methods] : According to The Evaluation Guideline of Surveillance System of Highly pathogenic Avian Influenza Virus Infection in China, four superior sites: Chongqing municipality, Guangzhou city, Hu'nan province and Jiangsu province were selected for evalution. Five cities and five counties in Hu'nan province, four cities and four counties in Jiangsu province, four districts in Chongqing municipality and four districts in Guangzhou city were selected as subordinate sites. At each site, health administration departments, CDCs and a general hospital were further selected. A face-to-face questionnare and in-depth interview were conducted using an identical questionnare and interview outline,including surveillance design, implementation, financial support, case diagnosis and report, laboraotory test,training and monitoring, existing problems and associate factors. In addition, a general hospital was investigated in each surveillance site, a retrospective case investigation was conducted among all all hospitalized poneumonia/AIDS patients in 2006, including clinical manifestations, epidemilogical history, dialogsis and treatment, All data collected by questionnaire, interview and case investigation were statistically analyzed.
results
1. Basic information: There are 1992 health facilities at county level or above conducting surveillance of pneumonia for unknown reason among four superior sites and only 1.6 pecent of health facilities(32/1992) once reported pneumonia cases for unknown reason. 40 persons from health administration departments received interview, 79 persons from all-level CDCs accomplished questionnare (68 persons of them received additional interview) and 65 persons from 30 health facilities received questionnare investigation(58 persons of them received additional interview).
2.the current situation of surveillance system used in health facilities and ivestigation of related influence factors:
20 percent of 30 investigated health facilities adopted direct network report when pneumonia for unknown reason case was found. 66.7 percent of hospitals thought that to conduct surveillance added much workload and 56.7 percent considered it might disturb routine work. 41.54 percent of 65 persons who received questionnare investigation felt it was hard to identify the defination of pneumonia for unknown reason case. There was no statistic difference between Grade III and Grade II hospitals. (X~2 = 0.39, P>0.5) 98.5 percent of doctors believed it was necessary to record epidemic history and collect serum sample for further confirmation in CDC. There was no statistic difference between Grade III and Grade II hospital medical officers when asked if the defination of pneumonia for unknown reason case was exact and easy to understand.
3.the current situation of surveillance system used in CDC and ivestigation of related influence factors:
60 percent of 30 target CDCs once received the report of pneumonia for unknown reason case and participated in arrangement and disposal. 93.7 percent of 79 target personnels believed the system was effective to control human avian influenza by advanced detection.59.5 percent thought it was easy for them to grasp details about reported cases. 89.9 percent considered it was effective to find new case in the early period. However, there was a difference in three levels which were province-, city- and county- level( X~2 = 7.25, P = 0.03 ). People thought it was hard for the expert group to make a confirmation or elimination of pneumonia for unknown reason case which resulted in statistic difference between city-level and county-level (X~2 = 13.45, P = 0.00) . Among 65 target personnels, 63.8 percent did not trust the report while 40 percent felt hard to understand the exact defination of surveillance case.
4.health administration departments interview
82.5 percent of 40 target persons thought the elimination program for pneumonia of unknown reason could be carried out in routine work effectively and there was no difference among the three levels. 67.5 percent considered the elimination mechanism ran well, 17.5 percent thought it was not so good and 7.5 percent thought bad. There was no difference among the three levels. 65 percent did not agree to obtain the permission before reported through internet.
4. retrospective investigation of hospitalized pneumonia cases: In 2006,there were 119,938hospitalized patients in these four Grade III hospitals, 4,888 of those were pneumonia and related cases of lung acute infection, accounting for 4.08 percent of all hospitalized cases; 818 cases were lung infection accounting for 16.73 percent of all related cases of acute infection;921 cases were pneumonia accounting for 18.84 percent of all related cases of acute infection.
there were 70,130 hospitalized patients in these four Grade II hospitals, 4,782 of those were pneumonia and related cases of lung acute infection, accounting for 6.82 percent of all hospitalized cases; 551 cases were lung infection accounting for 11.31 percent of all related cases of acute infection;377 cases were pneumonia accounting for 7.88 percent of all related cases of acute infection.
2,283 cases were consistent with the surveillance case definition, 37 of them were consistent with the defination of pneumonia of unknown reason, accounting for 1.62% of all investigated cases, 0.374 percent of pneamonia cases and related cases of lung acute infections and 1.95 per 10,000 of all hospitalized cases.
5. investigation on cases of pneumonia of unknown reason and human avian influenza:
427 cases were reported as pneumonia of unknown reason from the implementation of the surveillance system in Apr. 2004 to Mar. 9th 2007. 22 of them were identified to human avian influenza cases accounting for 5.2 percent. Conclusions and Recommendations
Since the surveillance system established in 2004, twenty-four cases of human avian influenza up to date which were found, reported and confirmed in China were from the surveillance system of pneumonia of unknown reason, so the surveillance system have great effect on the rate of iodentification,,reporting and diagnosis of human avian influenza. However, there were some problems: there should be more scientific case definition, more accurate understanding of the surveillance definition for clinical workers, simpler exclusion procedures; there are inappropriate contents and scope of humans avian influenza emergency prepairedness, excessive focus of surveillance, imperfect management, excessive workload of reporting and processing, weak capability of testing in CDC and clinical facilities at local units, insufficient funding, inadequate propagand. As a consequence, surveillance didn't reflect the actual situation and achieve the objectives. The simplicity and feasibility of surveillance systems needs to be improved.
Recommentations: Revise the surveillance protocol and add the suspect epidemiological history to the case definition; strengthen training and monitoring; Emergency surveillance program should be formulated according to the actual epidemic situation among either humans or animals with epidemiological investigation and analysis; The exclusion of diseases should be made only by the experts' consultation from the local hospital or at the prefecture level, higher level experts could be invited for diagnosis if necessary. The government all the level should take lead in the inplementaiton of human-centered policy, respect science and facts, and try to avoid over-reaction and take excessive interference; Enhance the laboratory's testing capability, explore the rapid diagnosis reagent for screening at the local units; For reflecting the human-centered thinking, the reward-and-punishment mechanism of case report, the experts' diagnosis and exclusion procedures, and the subsidy mechanism should be established; ensured the counterpart fund of the diseases of unknown reason surveillance at state and regional level; Strengthen the work of education and propagation.
引文
1.USCDC Updated Guidelines for Evaluating Public Health Surveillance Systems July 27,2001/50(RR13);1-35.
2.卫生部,《全国不明原因肺炎病例监测实施方案(试行)》,卫办疾控发[2004]93号,2004年.
3.卫生部,《全国不明原因肺炎病例监测、排查和管理方案》,卫应急发[2007]158号,2007年.
4.卫生部,《人感染高致病性禽流感应急预案》,卫应急发(2006)197号,2007年.
5.王陇德,主编.人感染高致病性禽流感,北京:人民卫生出版社,2007年:85.
6.Olsen SJ,Ungchsak K,Birmingham M,et al.Surveillance for avian influenza in human beings in Thailand.Lancet Infect Dis,2006;6(12):757-758.
7.Geneva.WHO manual on animal influenza diagnosis and surveillance.2002(doucement WHO/CDS/CSRNCS/2002.5.)
8.余红杰,舒跃龙.流感大流行的威胁及中国的应对.疾病监测.2005;20:505-507.
9.Olsen SJ,Ungchusak K,Birmingham M,et al.survillance for avain influenza in human beings in Thailand.Refection and Reaction.2006;6:757-758.
10.World Health Organization.Overview of the WHO Framework for Monitoring and Evaluating Surveillance and Response Systems for Communicable Diseases.Weekly Epidemiol Rec 2004;79(36):322-6.
11.World Health Organization.Protocol for the Assessment of National Communicable Disease Urveillance and ResponseSystems[R].WHO/CDS/CSR/ISR/2001.2.
12..王玫,李竹.公共卫生监测系统的评价.国外医学.流行病学传染病学分册,2003,20(4):196-197.
13.Chen H,Deng,Li Z,et al.Theevolution of H5N1 viruses in ducks in southern China.Proc Natl Acad Sci USA.2004;101:10452-10457.
14.Bridges CB,Lim W.Risk of influzra A infection among poultry workers,Hong Kong,1997-1998.J Infect Dis.2002,185:1005-1010.
15.Wright KE,et al.Typing and subtyping of influenza viruses in clinical samples by PCR.Journal of Microbiology 1995;33:1180-1184.
16.Yuen KY,et al.Clinical features and rapid viral diagnosis of human diseases associated with avain influenza A H5N1 virus.Lancet.1998;351:467-471.
17.Bureau of Epidemiology,Department of Diseases control,Ministry of Public Health.Thailand.Avian Influenza surveillance in human(2006,5:15-16).
18.Krug RM.Clues to the virulence of H5N1 viruses in humans.Science.2006;311:1562-1563.
19.Beigl JH,Farrar J,Han AM,et al.Avian A(H5N1)infection in humans.NEngl Med.2005;353:1374-1385.
20.Schalitssek C,Quack G,Klenk HD,etal.How to overcome resisitance of influenza Aviruses against adamantone derivatives.Antiviral Res.1998;37:83-95.
[1].中国卫生部.《全国不明原因肺炎病例监测实施方案(试行)》(卫办疾控发[2004]93号)
[2].中国卫生部.《全国不明原因肺炎病例监测、排查和管理方案》(卫应急发[2007]158号)
[3]王希江,曾光.传染病监测系统评价。地方病通报,2005,20(4):97-99.
[4]World Health Organization.Protocol for the Assessment of National Communicable Disease Urveillance and ResponseSystems[R].WHO/CDS/CSR/ISR/2001.2.
[5]World Health Organization.Overview of the WHO Framework for Monitoring and Evaluating Surveillance and Response Systems for Communicable Diseases.Weekly Epidemiol Rec 2004;79(36):322-6.
[6].杨功焕,曾勇民,谭健,等.中国综合疾病监测系统.疾病监测,1995,10(11):327-329.
[7].王玫,李竹.公共卫生监测系统的评价.国外医学.流行病学传染病学分册,2003,20(4):196-197.
[8].Chen H,Deng,Li Z,et al.Theevolution of H5N1 viruses in ducks in southern China.Proc Nat1Acad Sci USA.2004;101:10452-10457.
[9].Bridges CB,Lim W.Risk of influzra A infection among poultry workers,Hong Kong,1997-1998.J Infect Dis.2002,185:1005-1010.
[10].World Health Organization.Overview of the WHO Framework for Monitoring and Evaluating Surveillance and Response Systems for Communicable Diseases.Weekly Epidemiol Rec 2004;79(36):322-6.
[11].World Health Organization.Protocol for the Assessment of National Communicable ,Disease Urveillance and ResponseSystems[R].WHO/CDS/CSR/ISR/2001.2.