Infective respiratory syncytial virus is present in human cord blood samples and most prevalent during winter months.

Background: Human respiratory syncytial virus (RSV) remains the most common cause of severe lower respiratory tract disease amongst infants, and continues to cause annual epidemics of respiratory disease every winter worldwide. Demonstrating placental transmission of viable RSV in human samples is a major paradigm shift in respiratory routes considered likely for RSV transmission.

Methods: Droplet digital PCR (ddPCR) was used to identify RSV present in cord blood mononucleocytes (CBM).