New coronavirus is more infectious through eyes, airways than SARS, says study
Researchers from Hong Kong University’s school of public health have found that the novel coronavirus is up to 100 times more infectious through the eyes and airways than SARS.
A study by the University of Hong Kong has found that the eyes and airways are important routes for the novel coronavirus to enter the human body. The research found that the strain was up to 100 times more infectious than severe acute respiratory syndrome (SARS) and bird flu in two facial orifices tested by the public health experts.
Dr Michael Chan Chi-wai, from associate professor of the university's School of Public Health, and his research team compared the infection of COVID-19, SARS-CoV and the influenza viruses such as H5N1 and H1N1 using human upper respiratory tract and eye tissues in a Biological Safety Level-3 laboratory.
Laboratory tests revealed that the "virus level" of Sars-CoV-2 – the strain of coronavirus that causes Covid-19 – was far greater than for SARS in the upper respiratory airways and conjunctiva, the cells lining the surfaces of the eyes.
The team became among the first researchers worldwide to provide evidence the coronavirus can infect humans through both entry points when it published its findings in the latest issue of The Lancet Respiratory Medicine.
Dr Chan said: “We culture tissues from the human respiratory tract and eyes in the laboratory and applied them to study the SARS-Cov-2, comparing it with SARS and H5N1. We found that SARS-Cov-2 is much more efficient in infecting the human conjunctiva and the upper respiratory airways than SARS, with virus level some 80 to 100 times higher.
“This explains the higher transmissibility of Covid-19 than that of Sars. This study also highlights the fact that eyes may be an important route of SARS-CoV-2 human infection,” he added.
The study reinforces earlier advice to the public not to touch their eyes when in public areas, and that washing hands with soap and water or alcohol rub is essential in order to prevent the accidental transfer of the virus.
In a previous study, the team discovered that the coronavirus can remain alive for seven days on plastic and stainless steel surfaces.
The novel coronavirus outbreak was first reported in the central Chinese city of Wuhan late last December.
It has since developed into a pandemic, infecting more than 3.8 million people across the globe, claiming over 269,000 lives, according to data compiled by researchers at Johns Hopkins University.