The Evaluation Of Surveillance System Of Highly Pathogenic Avian Influenza Virus Infection In China

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.results1. 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 interview82.5 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 RecommendationsSince 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.