Performance of surveillance system of pneumonia with unknown etiology in two hospitals at municipal (prefecture) level in Anhui province

Objective To understand the performance of surveillance system of pneumonia with unknown etiology (PUE) in medical institutions and provide scientific evidence for the improvement of the system. Methods Newly admitted patients who met the PUE definition in 2 hospitals at municipal (prefecture) level in Anhui province were screened out by using hospital information system. Clinical specimen of PUE cases were collected for etiological detection. The difference in exposure history between the recorded by clinicians and the recalled by PUE cases were compared through medical record review and face to face interview. Results A total of 2 619 cases related to PUE were screened in the two hospitals, of whom 335 (13%) were classified as PUE cases. Only one case was reported as PUE to municipal CDC. The detected cases of PUE were mainly from pediatric ward (50%) and respiratory ward (30%). The cases of PUE detected in intensive care unit accounted for 48% of the total screening cases in that ward, higher than other wards. Among the 311 laboratory detected cases of PUE, 18 (6%) had positive results, all were seasonal influenza cases. Up to 97% of cases of PUE (303/311) had epidemiological exposure history records, but the records about epidemiological risk factors associated with emerging respiratory infectious diseases were limited. Conclusion The reporting rate of the cases of PUE by the surveillance system was low, indicating the unsatisfied performance of the system. The quality of PUE surveillance needs to be improved by means of the revision of the surveillance protocol.