PLE-5543

An infant, born term to a G1P1 mother, dies. Prior to death, the infant was noted to have intrauterine growth retardation, jaundice, hepatosplenomegaly, anemia, and bleeding due to thrombocytopenia. Periventricular calcification is observed on imaging, and histology reveals prominent intranuclear basophilic inclusions surrounded by a clear halo. In utero infection is suspected. What is the most likely etiologic agent?