Among our patients, the most common clinical features were fever (100%), arthralgia (90%), rash (50%), and conjunctivitis (40%) ( Table 2 ). Gastrointestinal and constitutional symptoms were less prominent. Arthritis was observed in only one patient, who had an effusion on the right knee. None had neurologic involvement or hemorrhagic manifestation. Table 3 presents a summary of the key laboratory findings among our patients throughout the course of their illness. White cell count, hemoglobin, hematocrit, platelet count, erythrocyte sedimentation rate for most patients were within the normal range. The mean nadir platelet count (6SD) was 1996115610 9 /L. Only one patient had severe thrombocytopenia (nadir platelet count, ,100610 9 /L) during the course of his illness. Elevated C-reactive protein levels (CRP, .10.0 mg/L) were observed in 60% of patients, but the peak C-reactive protein level was not significantly different between those who classified as severely ill and those who were not (mean, 40.3 mg/L vs. mean, 9.9 mg/L; P = 0.195). The mean peak alanine and aspartate transaminases (ALT and AST) (6SD) were 58636 U/L and 50625 U/L respectively. Both ALT and AST were 2-fold greater than the upper limit of normal in one patient, who had pre-existing liver cirrhosis. None of the patients had a clinically abnormal total protein, urea or creatinine level. Among our patients, the mean nadir protein level (6SD) was 6765 g/dL, and the mean peak urea and creatinine levels (6SD) were 5.161.7 mmol/L and 101616 mmol/L respectively. Lactate dehydrogenase level was the only laboratory parameter that was significantly higher in severely ill patients, compared to those who were not (mean, 732 U/L vs. mean, 525 U/L; P = 0.047).