Detection of Nipah Virus in Human Milk: A Novel Finding

Nipah virus (NiV) causes severe diseases in humans with a high case fatality rate. The primary risk factors for NiV infection in Bangladesh are drinking raw date palm sap (DPS) contaminated with Pteropus fruit bat secretions/excretions or close contact with or exposure to the body fluid of an individual with NiV infection. During the 2023 NiV outbreak investigation in Bangladesh, the breast milk of a NiV-infected nursing mother was tested by real-time reverse transcriptase polymerase chain reaction (RT-PCR) for detection of NiV-RNA. The newborn was also tested as a suspected NiV-infected subject. NiV, specifically NiV RNA, was detected in the breast milk sample. Through the investigation, it was determined that the mother consumed raw DPS 9 days before the delivery. The newborn was also confirmed as NiV positive and had exposure to maternal bodily fluid while breastfeeding, and was in prolonged maternal contact during caregiving. Although the detection of NiV RNA in breast milk does not equate to viability and transmissibility of the virus, this finding provides preliminary evidence that warrants further investigation into the potential role of breast milk in postnatal transmission of NiV. Our findings advocate incorporating breast milk testing into NiV diagnostic protocols for symptomatic mothers. This advancement will broaden our understanding of postnatal transmission of NiV and pave the way for more effective containment strategies.