Novel Coronavirus Detected in Breast Milk: Transmission Through Lactation Not Yet Determined

As is known to all, novel coronavirus is mainly spread by respiratory droplets and contact. Whether it can enter the breast milk and spread to the infant through lactation has been receiving much attention. Previous academic papers have not provided the evidence of novel coronavirus found in breast milk.However, a new study has found a novel coronavirus positive in breast milk.

Novel coronavirusRNA can be detected in breast milk, according to a new study published in the lancet by the university of ulm in Germany, but further research is needed on milk samples from nursing women and whether they might be transmitted through breastfeeding to develop recommendations on whether mothers of covid-19 should breastfeed, according to media reports.

In the study, the team tested the milk of two nursing mothers infected with novel coronavirus. After the mother fed and the nipple was sterilized, the milk was collected with a pump and stored in a sterile container at 4℃ or -20℃ until further analysis.They used rt-qpcr to detect the viral load of the novel coronavirusN gene and the orf1b-nsp14 gene in both whole and skim breast milk.

The researchers defined inpatient delivery as day 0, and all four milk samples collected from the first mother from admission to discharge were negative.By contrast, novel coronavirus RNA was detected in the milk of mother no. 2 on days 10 (left and right), 12 and 13.After that, all the breast milk samples collected by mother no. 2 were negative.

Since the composition of breast milk may affect the isolation and quantification of novel coronavirusRNA, the researchers determined the recovery rate of viral RNA from novel coronavirus breast milk that was continuously diluted.They observed an 89.2 percent reduction in the recovery of virus in full-fat breast milk and a 51.5 percent decrease in the recovery of skim milk, suggesting that the actual viral load in the full-fat breast milk of mother no.2 May have been higher than detected.

The researchers detected novel coronavirusRNA in a sample of no.2 mother’s milk for four days.While viral RNA was detected in the breast milk of mother no. 2, the newborn also developed mild covid-19 symptoms and was confirmed positive for novel coronavirus.

Mother no. 2 has been wearing a surgical mask since the onset of symptoms and has followed safety precautions when handling or feeding her newborn (including proper hand and breast disinfection, strict cleaning and disinfection of the milk pump and tube).But it remains unclear whether newborn no. 2 was infected through breastfeeding or other transmission.

In addition, it should be noted that novel coronavirus nucleic acid test positive does not necessarily mean that there is a complete novel coronavirus in the milk, but it may also be avirus fragment, so its infectivity also needs further study.