Epidemiological Characteristics of An Outbreak of Severe Acute Respiratory Syndrome in Dongcheng District of Beijing From March to May 2003

Objective To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003.Methods Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention(CDC)and supplemented by other channels were collected. Clinicians and officials of local hospitals were interviewed in groups and medical records of fatal cases of SARS were reviewed to verify the diagnosis. Stored serum specimens of the patients were detected for IgG antibody against SARS Co-V by enzyme-linked immunosorbent assay (ELISA). All the data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. Results Outbreak of SARS in Dongcheng District started on March 14, 2003 with a peak in mid- and late April, and dropped in early May. A total of 572 reported cases were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, regular pneumonia, measles and rubella, etc. Actually, 473 SARS cases, which included390 (82.5%) probable cases and 83 (17.5%) suspect cases, were analyzed. About 90% of the probablecases were positive for IgG antibody. Attack rate of SARS in permanent residents of Dongcheng District was 28.3 per 100000. Forty-one of them died, with a case-fatality rate of 8.7%. Persons were all susceptible to infection of SARS Co-V, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. Nogender difference in SARS cases was found. Number of SARS cases in health-care workers (HCWs)accounted for 18.0% and that in retired workers accounted for 15.4% of the total cases. Cases occurred in all 10 sub-districts of Dongcheng, with the highest in Beixinqiao and Andingmen Sub-districts. Totally, 230 of the 572 notified cases (40.2%) were hospitalized at local hospitals under the jurisdiction of Dongche