Objective: To investigate the differences among various transmission generation of severe acute respiratory syndrome (SARS) by comparing the corresponding clinical data.
Methods: The clinical data of 84 patients with SARS were retrospectively studied, 66 women and 18 men, mean age (29.2 +/- 10.3) years old, 96.4% of whom were health care workers. All subjects had exposure to a source patient and the epidemic progressively propagated in a short time. For the infectious chain, we defined these patients who had exposure to a source patient as the primary cases, which included 35 patients (41.7%). Patients who got the disease by exposure to the primary cases were defined as secondary cases, which included 34 patients (40.5%). Similarly, the tertiary cases included 15 patients (17.9%).
Results: (1) No statistical differences in age, sex ratio, incubation period and hospitalization duration among various infectious generations were found (P > 0.05). (2) With descending in infectious generations, the initial temperature lowered, and cases with cough decreased (P < 0.05) with no statistical differences in the peak temperature, other accompanying symptoms and leukopenia (P > 0.05). (3) With descending in infectious generations, the course from the appearance of pulmonary lesions to their resolution shortened (P < 0.05). No differences were found in the maximal involved pulmonary fields, duration from initial fever to appearance of pulmonary lesions and course from the initial pulmonary lesions to their peak among the above three generations (P > 0.05). (4) No statistical differences were found in ways of oxygen therapy and classes of antibiotics prescribed (P > 0.05). With descending in infectious generation, cases treated with methylprednisolone, human gamma-immunoglobulin, interferon-alpha, and antiviral drugs (oral ribavirin or oseltamivir) increased (P < 0.05) and the duration of their use also increased (P < 0.05).
Conclusions: With descending in infectious generations, the clinical features of SARS may become ameliorated.