Congenital dengue infection during the epidemic in Argentina in the 2023- 2024 period: a multicenter registry

i. Objective: To describe clinical, laboratory, and follow-up characteristics of neonates with confirmed dengue infection. ii. Study design: Observational, descriptive, retrospective, and multicenter study including neonates with confirmed congenital dengue hospitalized at 6 centers from Argentina, between July 2023 and July 2024. Confirmation required virological or serological testing in both mother and neonate. Data were collected anonymously via REDCap and analyzed with RStudio. iii. Results: 58 neonates were included. Most pregnant individuals presented with fever, myalgia, and headache. Maternal diagnosis was confirmed mainly by NS1 antigen (59%) and PCR (43%); 9% were serotyped, with 4/5 serotypes corresponding to DENV1. Fifty-two pregnant individuals were hospitalized. Median gestational age at birth was 38 weeks; and 21% of neonates were preterm. Most deliveries were cesarean. At admission, 74% of neonates were asymptomatic; 26% showed respiratory distress or temperature instability. Diagnosis was confirmed by PCR in 59% of neonates. Two preterm neonates required mechanical ventilation. Median hospital stay was 9 days. 57% of neonates developed thrombocytopenia within the first week of life. No deaths or sequelae were recorded in neonates. One mother died because of severe dengue with shock. iv. Conclusion: In this multicenter registry, 74% of neonates were asymptomatic and 21% preterm, with no deaths or sequelae at discharge and 30 days of follow-up.