Researchers from the University of North Carolina (UNC) School of Medicine have created an image of the SARS-CoV-2 virus in human bronchial epithelial cells, ready to be transmitted from one person to another.
Dr Camille Ehre conducted an experiment in her laboratory at the University of North Carolina (UNC) School of Medicine, in order to demonstrate how severe a SARS-CoV infection of the respiratory tract can be.
The team of researchers inoculated the SARS-CoV-2 virus into human bronchial epithelial cells, which were examined 96 hours later by scanning electron microscopy.
The colorized image shows infected hair cells with mucus strands (yellow) attached to the tips of the cilia (blue). Cilia are hair-like structures on the surface of airway epithelial cells that carry trapped mucus and viruses from the lung.
Likewise, the magnified image shows the structure and density of the SARS-CoV-2 virions (red) produced by the epithelia of the human respiratory tract. Virions are the complete and infectious form of the virus released on respiratory surfaces by infected host cells.
“Virus production was approximately 3 × 106 plaque-forming units per culture, a finding that is consistent with the high number of virions produced and released per cell,” the authors wrote.
The research helps illustrate the incredibly high number of virions produced and released per cell within the human respiratory system. According to the scientists, the large viral load is a source of spread of infection to multiple organs of an infected individual and likely explains the high rate of transmission of COVID-19 to others.
The images are an argument for infected and uninfected individuals to wear masks to limit the transmission of SARS-CoV-2, they say.
The images were published in the New England Journal of Medicine.