[Analysis of severe acute respiratory syndrome in Beijing].

OBJECTIVE: To study the clinical, laboratory, and radiologic features of 34 cases of severe acute respiratory syndrome (SARS) in Beijing. METHODS: All patients were admitted to the isolation wards. Their demographic, clinical, laboratory, and radiologic characteristics were analyzed. Univariate and multivariate analyses were performed. RESULTS: Eight patients came from a family, and 15 patients were medical staff. The mean age of patients was (33.4 +/- 13.4) years. The latent period varied from 2 to 14 days (median 4 days). The most common symptoms were fever (100%), palpitation (91.7%), myalgia (79.2%), headache (70.8%), diarrhea (73.9%) and cough (58.3%). The mean leucocyte count was (4.6 +/- 1.4) x 10(9)/L, and the mean lymphocyte ratio was 0.27 +/- 0.11. 68.4% of the patients had lymphopenia (absolute lymphocyte count < 1.3 x 10(9)/L). Other common findings included elevated levels of serum alanine aminotransferase, lactate dehydrogenase and erythrocyte sedimentation (76.2%, 28.6% and 47.8%, respectively), and decreased levels of serum iron and albumin (63.2% and 47.8%, respectively). Thirty-two cases had abnormal chest radiographs. In 2 cases in whom typical lung opacities could not be found on the initial plain chest radiographs, thoracic CT proved to be useful. Postmortem examination of 1 patient revealed marked edema with foci of hemorrhage and hyaline membrane formation in the lungs, hemorrhage necrosis and a obvious decline of cells in lymph glands. In a multivariate analysis (Stata 7.0), the independent predictor of an adverse outcome was advanced age (odds ratio per decade of life, 1.6; 95% CI, 1.08 to 2.63; P = 0.007). CONCLUSIONS: Fever, lymphopenia, low serum iron and chest radiograph are helpful to diagnose SARS early; age is the independent predictor of an outcome.