A neonate born at 36 weeks' gestation manifests severe hydrops fetalis, hepatosplenomegaly, generalized icterus, and scattered ecchymoses of the skin. Laboratory studies show a hemoglobin concentration of 9.4 g/dL and platelet count of 67,000/mm3. Ultrasound of the head shows ventricular enlargement. Death occurs 14 days after birth. At autopsy, there is extensive subependymal necrosis, with microscopic evidence of encephalitis. Within the areas of necrosis, there are large cells containing intranuclear inclusions. Congenital infection with which of the following organisms is most likely to produce these findings?

About 10% of cytomegalovirus-infected neonates have extensive infection with inclusions found in many organs. Severe anemia and myocardial injury cause hydrops, and the brain is often involved. The renal tubular epithelium can be infected, and large cells with inclusions can be seen with urine microscopic examination in some cases. Cytomegalovirus manifested in neonates may have been acquired trans placentally, at birth, or in breast milk. Herpes simplex virus is usually acquired via passage through the birth canal and does not cause a periventricular leukomalacia. HIV infection in utero does not produce marked organ damage. Parvovirus infection may cause a severe fetal anemia. Congenital rubella manifests in the first trimester, often with cardiac defects.