Case report: Chikungunya and neonatal immunity: Fatal vertically transmitted chikungunya infection

Abstract

Chikungunya is a mosquito-borne infectious disease that has emerged as a global pathogen. The virus can pass vertically from mother to child especially during the perinatal period, with an intrapartum vertical transmission rate of 50%. Approximately half of the neonates infected with chikungunya present with severe symptoms and infrequently death. This report summarizes two severe cases of vertically transmitted neonatal chikungunya infection. One case was confirmed by real-time reverse transcription polymerase chain reaction and the other fulfilled clinical and epidemiological criteria. Both infants presented on day 3 with abdominal distension, reduced perfusion pressure, and hypotension; acrocyanosis progressing to ischemic digits; and respiratory distress. Both died within 24-48 hours of presentation. The severity of symptoms observed is likely due to a combination of contamination of the fetal blood from highly viremic mothers during delivery and a low innate antiviral type-1 interferon response. Further examination of the neonate's innate immune response to chikungunya may provide clues for the development of potential treatment or vaccine interventions.