Acute dengue fever in a neonate secondary to perinatal transmission

Background: Dengue in pregnancy is associated with adverse maternal and fetal outcomes, including perinatal transmission. Case report: We report a case of neonatal dengue in a baby born to a 29-year-old primigravida at 38 weeks of gestation. She developed acute dengue fever 2 days prior to delivery. Her dengue nonstructural protein 1 antigen was reactive. She delivered a term baby girl via spontaneous vaginal delivery. Her fever persisted in the post-partum period which was associated with post-partum hemorrhage, altered coagulation, and liver function. She was clinically diagnosed to have hemophagocytic lymphohistiocytosis complicated with disseminated intravascular coagulation and treated with intravenous (IV) dexamethasone and multiple blood products, including fresh frozen plasma and platelet concentrate. She recovered in over the next 5 days. The baby girl was born with a birth weight of 3040g and developed fever on the third day of life with poor perfusion, associated with mottling and hypotension. The baby was treated with IV fluids, inotropes, and supportive care. The fever subsided after 48 h, along with clinical improvement, but continued with thrombocytopenia. The baby did not have any bleeding. Platelet recovery started on the 11^thpostnatal day (i.e., the 8^thday of illness), and platelet count was normalized at 2 weeks. Dengue serology immunoglobulin M by enzyme-linked immunosorbent assay was positive for both mother and baby. The clinical diagnosis was confirmed by laboratory tests. Conclusion: Dengue fever in mothers very late in pregnancy can cause symptomatic dengue infection in neonates.