[Analysis of severe acute respiratory syndrome in Beijing]

To study the clinical, laboratory, and radiologic features of 34 cases of severe acute respiratory syndrome (SARS) in Beijing.

All patients were admitted to the isolation wards. Their demographic, clinical, laboratory, and radiologic characteristics were analyzed. Univariate and multivariate analyses were performed.

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).

Fever, lymphopenia, low serum iron and chest radiograph are helpful to diagnose SARS early; age is the independent predictor of an outcome.