Evaluation Of The Surveillance System For Pneumonia Of Unknown Etiology

ObjectiveThis study is aimed to understand the operating situation of the surveillance system for pneumonia of unknown etiology (PUE). To analyze the major problems in operation, and provide recommendations to make the surveillance system operate more effectively.MethodDescriptive epidemiological method is used to analyze the national reporting situation of the PUE surveillance system, and the reporting approach of targeted diseases related to PUE surveillance system from 2004 to 2016. Cross-sectional study is used to analyze clinicians’ knowledge, attitude and practice to the surveillance system, and the system’s operating situation in medical settings. The indicators used to evaluate the PUE surveillance system include sensitivity, positive predictive value (PPV),acceptability and timeliness through the descriptive and investigating study above.Results1. The case reporting situation of PUE surveillance system from 2004 to 2016(1) A total of 1666 PUE cases were reported to the system, among which 8%(125/1666) were emerging respiratory infections. The 125 cases included 41 human infection with H5N1 avian influenza, 81 human infections with H7N9 avian influenza,2 human infections with H5N6 avian influenza, 1 human infection with H9N2 avian influenza. PPV of PUE surveillance system is 8%.(2) The average time interval between onset and diagnosis of PUE cases was 6.0 days, and the interval between diagnosis and reporting of cases was 0.5 days, and the interval between reporting and check of reported cases was 0.1 days. The average time interval between onset and diagnosis of the majority of outbreaks was longer than the non-reported peak hours. Time interval between cases’ diagnosis and reporting, between reporting and check were shorter during outbreaks.2. Reporting approach analysis of human infection with avian influenza and other emerging infectious disease(1) A total of 988 human infection with avian influenza and EA-H1N1 swine influenza cases were reported from 2004 to 2016. 13% (125/988) were reported through PUE surveillance system, 49% (483/988) were reported through notifiable reporting approach, and 19% (183/988) through hospitalized pneumonia case monitoring. Sensitivity of the PUE surveillance system to detect target disease is about 13% (125/988).(2) Before outbreak of human infection with H7N9 avian influenza in 2013, cases of human infection with H5N1 avian influenza were all reported through PUE surveillance system. After the emergence of human infection with H7N9 and other type avian influenza, 53% (453/861) were reported through notifiable reporting approach, 18% (159/861) through hospitalized pneumonia case monitoring, only 9%(78/861) through PUE surveillance system.3. Clinicians’ knowledge,attitude and practice towards PUE surveillance system(1) Among the interviewed 487 clinicians, 83% (403/487) knew the system.Among clinicians who knew the system, about 83% reported they received related training, and only 9% could fully grasp PUE case definition.(2) 51% (250/487) clinicians had encountered patients who met the PUE case definition, among whom 55% (139/250) encountered 1 -5 PUE cases in the past year,76% (166/220) had reported cases to related personnel or departments in hospital.More than 84% clinicians reported the reporting procedure was simple and feasible,reporting was helpful to the patient’s diagnosis and treatment, and they received the test results and timely response from related departments after reporting.(3) 48% (79/166) Clinicians reported cases for cases had no clear diagnosis and poor treatment effect; 36% (30/84) didn’t report cases for they don’t know PUE surveillance work. 59% (288/487) clinicians thought cases with severe illness status need more attention, and cases of probable infectious disease/clusters should reported to CDC.4. Operating situation of PUE surveillance system in medical settings(1) During investing period, a total of 2619 cases who may be related to PUE diagnosis were screened in two hospitals. Among whom, 13% (335/2619) cases met the PUE case definition. Only 0.3% (1/335) PUE case was reported to municipal center for disease control and prevention (CDC).(2) Among 311 PUE cases who had laboratory pathogenic detection results, 6%(18/311) had positive results, but they were all seasonal influenza. 61% (11/18)cases were positive for influenza A virus, 39% (7/18) were positive for influenza B virus (Victoria type).(3) Clinicians’ reasons for not reporting cases who met the PUE case definition were mainly: 76% they didn’t know the PUE surveillance work, 53% they didn’t understand PUE case definition. But the awareness rate of PUE surveillance work increased as clinicians’ working years increase.Conclusion1. The PPV of PUE surveillance system is 8%, timeliness of the PUE surveillance system is good. The system has played an important role in detection of cases in early stage of human infection with avian influenza outbreak. But after human infection with H7N9 avian influenza was included in type B notifiable infectious diseases in October of 2013, notifiable reporting and hospitalized pneumonia case monitoring become the main reporting approaches. And PUE surveillance system’s role of detecting human infections with avian influenza has been weakened.2. There is a high proportion of PUE case in hospital, but the reporting rate and the positive rate of target pathogen in PUE cases is very low. PUE case definition has a poor specificity.3. PUE surveillance system has a good acceptability from reporting stakeholder,clinicians. But clinicians have a poor understanding and command of the system.SuggestionsThe objective of PUE surveillance system should be repositioned as soon as possible,and the surveillance case definition should be modified according to the objective to improve specificity. PUE surveillance system is still in operation, before new version of the surveillance protocol is issued, training of PUE surveillance work should be strengthened.