The ability of the new coronavirus (SARS-CoV-2) to enter breast milk and spread it to infants through breastfeeding has been a matter of concern. No evidence of new coronavirus has been found in breast milk in previous academic papers. However, a study from Germany published in The Lancet, an international leading medical journal, showed that new coronavirus RNAs could be detected from breast milk. The researchers recommend that further research be conducted on breast milk samples and the possibility of transmission through lactation in lactating women to develop recommendations on whether COVID-19 mothers should breastfeed.
The study, published may 21 localtime by the Institute of Molecular Virology at Ulm University Medical Center, is published in the local paper entitled “Detection of SARS-CoV-2 in human breastmilk”. The team tested the milk of two nursing mothers infected with the new coronavirus, both of whom were informed and consented to the study, and all samples were anonymous.
As shown above: After giving birth, mother 1 developed mild COVID-19 symptoms and tested positive for SARS-CoV-2. After the space isolation of mother 1 and her baby (newborn No. 1), the newborn 1 also tested positive for the new crown and developed breathing problems, but since then both Mother 1 and newborn No. 1 have recovered.
Mother 2 lives in the same hospital and ward as mother 1. After the birth, mother 2 and her baby, Mother 2 and Mother No. 1 and Newborn No. 1, were brought back to the same room and stayed in the same room until Mother 1 tested positive for SARS-CoV-2 and was quarantined.
Mother 2 and newborn No. 2 were discharged from the hospital on the fourth day. Shortly thereafter, mother 2 developed mild COVID-19 symptoms and began wearing surgical masks throughout the day. Mother 2 tested positive for SARS-CoV-2 on the 8th day. Three days later, newborn No. 2 WAS positive for SARS-CoV-2, and due to neonatal jaundice and severe breathing problems, newborn No. 2 was admitted to hospital again and underwent UV treatment and ventilation treatment. Newborn no. 2 tested positive for RSV and SARS-CoV-2.
Mother 1 still tested positive for the virus 22 days after her first diagnosis, the 13th day after her first positive. Rt-qPCR analysis of breast milk samples from two mothers found that on the 10-13th day, the mother-of-two’s breast milk had neo-coronavirus RNA, while the sample of mother 1 was negative.
In terms of breast test details, after mother feeding and nipple disinfection, the researchers used pumps to collect their milk and store it in sterile containers at 4 degrees C or -20 degrees C until further analysis. They used RT-qPCR to detect viral loads of the new coronavirus N gene and the ORF1b-nsp14 gene in full-fat breast milk and skimmed breast milk.
The researchers defined hospital delivery as day 0, when mother 1 was admitted to hospital, and the four breast milk samples collected tested negative. In contrast, mother 2’s milk detected RNA for the new coronavirus on the 10th day (left and right milk), day 12 and 13. After that, the breast milk samples taken by Mother 2 were negative.
In full-fat breast milk and skimmed breast milk, the Ct values of the new coronavirus N were 29.8 and 30.4, respectively, corresponding to 5 square copies/mL of 1.32 x 10 and 4 square copies/mL of 9.48 x 10, respectively. Because the composition of breast milk may affect the isolation and quantification of neo-coronavirus RNA, the researchers measured the recovery rate of viral RNA in breast milk that continuously dilutes the neo-coronavirus. They observed an 89.2% reduction in the recovery rate of the virus in full-fat breast milk and a 51.5% reduction in the recovery rate of skimmed milk, suggesting that the actual viral load in whole milk for mother 2 may be higher than is detected.
For four consecutive days, the researchers detected the new coronavirus RNA in a mother’s milk sample. Viral RNA was detected from mother 2’s milk, and newborns also developed mild COVID-19 symptoms and were confirmed to be POSITIVE for SARS-CoV-2. Mother 2 has been wearing surgical masks since the onset of symptoms and follows safety precautions when handling or feeding newborns (including moderate disinfection of her opponents and breasts, strict cleaning of milk pumps and tubes and disinfection).
However, it remains unclear whether the newborn has been infected through breastfeeding or other forms of transmission.
In addition, it should be noted that positive testing for neo-coronavirus nucleic acid does not necessarily mean that there is a complete new coronavirus in the milk, it may also be a virus fragment, so its infectiousness also needs further study.
Because pregnant women and babies are quite vulnerable, there has been a focus in academia about whether mother-to-child transmission is established and whether breast milk can detect new coronaviruses, and several academic papers have focused on these issues.
On April 18, 2020, professor Qiao Jie and Professor Zhao Yangyu of Peking University’s Third Hospital published the New England Journal of Medicine, The New England Journal, IF: 70.670, entitled “Clinical Clinical Sologist of the women infected with Coronavirus Disease” 2019 in Wuhan, China (“Clinical characteristics of new maternal coronavirus pneumonia in Wuhan, China”). Three of the breast milk samples were tested for SARS-CoV-2 nucleic acid, and the results were negative.
On March 12, 2020, Tongji Hospital, affiliated with Tongji Medical College of Huazhong University of Science and Technology, published a case report on newborn infection with the new coronavirus in the international infectious disease journal Clinical Infectious Diseases, and her mother’s breast milk sample was negative.
On February 12, 2020, the leading medical journal, The Lancet, published a paper, “Clinical Characteristics of 9 Cases of COVID-19 Infection in Pregnancy and Potential for Vertical Intrauterine Transmission: A Case Review.” Professor Zhang Yuanzhen of Zhongnan Hospital, Wuhan University, Professor Hou Wei of the Institute of Medical Viruses of Wuhan University’s School of Basic Medicine, and Professor Yang Huixia of Peking University First Hospital tested samples of breast milk from six patients, which were also negative.