RESUMO
We report a case of vertical transmission of dengue infection in an infant. The mother's was a term pregnancy with a history of chronic hypertension. She presented with high fever of 3 days duration 5 days prior to delivery. Her initial complete blood count showed platelet count of 64,000/mm3. Dengue hemorrhagic fever was diagnosed 2 days later and symptomatic treatment was given. During labor her platelets dropped to 11,000/mm3 and platelet concentrate was given. Cesarean section was performed due to prolonged second stage of labor. Her infant was normal at birth except for petechiae on the left thigh. The child's platelet count was 34,000/mm3 and low grade fever was detected on the first day. Clinical sepsis was suspected and antibiotic treatment was started and continued for 4 days until all the cultures came back as negative. Both mother and her baby made an uneventful recovery and were discharged 6 days after delivery with normal platelet counts. Maternal blood was positive for IgM antibody to dengue virus. Both cord blood and the baby's blood were positive for dengue virus serotype 2 by PCR.