To the Editors:We managed recently a boy with acute parvovirus infection. A 14-yearold boy with hereditary spherocytosis was brought to the hospital in shock. He had a 1-week history of fever, watery diarrhea and vomiting. On arrival, he was jaundiced and lethargic. Temperature was 38.1°C, heart rate 160/min, respiratory rate 28/min, blood pressure 90/40 mm Hg and O 2 saturation 94%. Splenomegaly unchanged from previous was present. Rash was absent, and he was mildly dehydrated.Investigations revealed hemoglobin of 101 g/L, white blood cell count 12.2 ϫ 0 -2.4 mmol/L). There was evidence of coagulopathy ͓International Normalized Ratio 3.02 seconds (normal, 0.9-1.1 seconds); partial thromboplastin time, 104 seconds (normal, 25-35 seconds)͔; renal dysfunction ͓blood urea nitrogen, 28.9 mmol/L (normal, 2.9-7.1 mmol/L); creatinine, 250 mol/L (upper normal, 106 mol/L)͔; and hepatic dysfunction ͓aspartate aminotransferase, 389 units/L (normal, 0-36 units/L); alanine aminotransferase, 78 units/L (normal, 0-40 units/L); unconjugated bilirubin, 27 mol/L (normal, 0-17 mol/L); conjugated bilirubin, 58 mol/L (normal, 0-2 mol/L)͔.He required fluid resuscitation, intubation and inotropic support. His hypotension, coagulopathy and renal dysfunction improved during the next 48 hours, and he was extubated on the third hospital day. During the next 4 days, anemia (66 g/L) with reticulocytopenia (Ͻ1%) and thrombocytopenia (9 ϫ 10 9 /L) unresponsive to platelet transfusion developed. Petechiae, bleeding from venipuncture sites and sub-