Several studies have reported the detection of ribonucleic acid (RNA) specific for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the breast milk of women recently infected with the virus.New research released in medRxiv* The preprint server investigates the relationship between viral RNA and infectious viruses to reveal the occurrence of vertical transmission via breast milk.
Currently, the SARS-CoV-2-induced coronavirus disease 2019 (COVID-19) pandemic infects more than 134 million people worldwide. Most of these are adults and children are a minority.
Vertical transmission due to breastfeeding?
Infant infections account for about 2% of all infectious diseases in the United States. Most of these infections are mild and give good results, but severe or fatal illnesses are rarely reported.Although rare, the disease can be complicated Pediatric multisystem inflammatory syndrome (MIS-C), even after the child has recovered.
As a result, COVID-19 during pregnancy and lactation has become a complication in many ways. One is the exposure of infected mothers to the extent that babies are at risk of being infected with the virus by breastfeeding.
Some studies have shown that breast milk does not infect the virus, and most health and professional agencies are careful to avoid respiratory infections with the virus in the event of a recent infection, but breast milk if the mother so desires. We encourage them to continue raising their children.
Purpose of research
A previous study by the same researcher showed that out of 64 samples of breast milk from 18 recently infected women, only one contained viral RNA. The infectious virus was not recovered from any sample. In addition, pasteurization by the holder method leads to virus inactivation.
Current research is looking for viral RNA in breast milk in a larger cohort. If found, it will be tested for subgenomic RNA. This indicates active replication and therefore virus infectivity. Researchers have also found that infectious SARS-CoV-2 can withstand changes in milk temperature.
Viral RNA present in breast milk
Breast milk samples from 110 women included 9 with symptoms who were negative for the polymerase chain reaction (PCR) test and 36 with untested symptoms, 65 were positive. .. The number of samples was 285.
Most women were Caucasian, non-Hispanic, with a median age of 36 years and about 90% had symptomatological COVID-19. About 1 in 10 people were hospitalized, and 2 of them had respiratory failure.
Two-thirds of hospitalized women were pregnant, two of whom were seriously ill at birth and required extracorporeal membrane oxygenation (ECMO).
One woman who had no symptoms or test results had viral RNA in her milk. In addition, one milk sample from each of six of the 65 confirmed infected women contained the virus. In these 7 cases, repeated samples collected after 1-97 days were unable to show viral RNA.
None of the seven-member group showed signs of infection after breastfeeding.
No evidence of SARS-CoV-2
From the entire group of breast milk samples, 160 were cultured for the virus and subgenomic RNA was also searched using real-time reverse transcriptase-polymerase chain reaction (RT PCR). The latter refers to RNA produced during viral replication for protein synthesis.
All cultures were negative and no sgRNA was detected. However, the sgRNA test gives positive results only in about 50% of culture-positive nasopharyngeal samples.
Testing the stability of the virus in breast milk
To ensure that SARS-CoV-2 remains in freeze-thawed milk and is detected by culture, researchers spike milk samples from two healthy women with the infectious virus and then freeze. It has melted.
Milk was stored at 4 ° C for 3 days and then cultured. Even after three freeze-thaw cycles, the sample was strongly positive for the virus and showed a cytopathic effect in culture. This ruled out false-negative results from viral inactivation due to temperature changes during storage of the experimental samples in this study.
What is the impact?
This result strongly suggests that breastfeeding is not contraindicated in women recently infected with SARS-CoV-2. In this study, many viral cultures were used to investigate the risk of vertical transmission in breast milk and the incidence of viral RNA.
“”It was found that almost no SARS-CoV-2 RNA was detected in breast milk samples of women with confirmed SARS-CoV-2 infection... Even if RNA was detected, it was not a sign of an infectious virus.
Further investigation is needed to validate this conclusion.
medRxiv publishes unpeer-reviewed preliminary scientific reports and should not be considered definitive, guide clinical / health-related behaviors, or be treated as established information.
The study found no evidence of SARS-CoV2 infection from breast milk
Source link The study found no evidence of SARS-CoV2 infection from breast milk