Excretion of SARS-CoV-2 in breast milk: a single-centre observational study.

Background: Breast feeding by SARS-CoV-2-infected mothers has been a concern because of the possibility of excretion of virus in breast milk. Objective: To detect SARS-CoV-2 in expressed breast milk (EBM) of mothers infected with SARS-CoV-2 and clinical outcome of neonates delivered and breast fed by them. Design: A single-centre, prospective observational study involving 50 SARS-CoV-2-infected mothers and their 51 neonates. Setting: A tertiary care hospital in Eastern India. Participants: SARS-CoV-2-infected mothers and neonates delivered by them. Main outcome measures: We investigated the presence of SARS-CoV-2 in the breast milk of mothers, who tested positive for this virus in their nasopharyngeal swab (NPS). Clinical outcome was assessed in neonates breast fed by these mothers after 1 month of the postnatal period. Results: 50 SARS-CoV-2-positive expectant mothers were enrolled for the study. One out of 51 neonates, who delivered through lower segment caesarean section at term gestation and tested SARS-CoV-2 negative, died due to severe birth asphyxia. One sample of EBM was collected from each of the 49 mothers within 4 days of delivery. All EBM samples tested negative for SARS-CoV-2 through real-time reverse transcriptase-PCR (RT-PCR). All the newborns were screened twice for presence of SARS-CoV-2 RNA in their NPS, by RT-PCR. 2 of 51 neonates had COVID-19 infection after 24 hours of life. Caregivers of 37 of 50 alive neonates responded to follow-up via telephone. Except for minor feed intolerance in one (1 of 37) neonate, all neonates were reported well after 1 month of their age. Conclusion: All the samples of breast milk were negative for SARS-CoV-2. Most of the neonates remained asymptomatic on breast feeding, whose mothers had SARS-CoV-2 infection before delivery.