Vertical transmission of fatal Rift Valley fever in a newborn.

Rift Valley Fever (RVF) is a viral disease transmitted to humans by mosquito bite and contact with animals or their infected tissues. Other modes of transmission include aerosol inhalation and possibly ingestion of raw milk from infected animals. We present a 5-day-old neonate with fatal RVF. Onset of the infant's illness on the 2nd day of life combined with positive RVF-IgM and serological evidence of maternal disease supports vertical transmission.