Researchers from the University of Hong Kong said people should keep on wearing a face mask in the fight against the Covid-19 pandemic. They said on Sunday a study using hamsters showed surgical masks are effective in significantly reducing non-contact transmission of the virus.
The university's microbiologists put two groups of hamsters, one infected with the coronavirus and the other healthy, in two adjacent but different sets of cages, to find out if surgical masks could help prevent the sick hamsters from transmitting the virus to the healthy ones.
They have also installed fans near the cages to create an air flow, which could help transmit the virus.
Three sets of experiments were carried out to test the effectiveness of surgical masks.
In the first experiment, no surgical masks were placed between the two groups of hamsters; while in the second, a mask was placed near the cages housing the infected hamsters – as if they were wearing a mask. And in the third, a mask shielded the cages housing healthy hamsters.
Renowned microbiolgist Professor Yuen Kwok-yung, who led the study, said the results confirm that surgical masks do make a difference in preventing the spread of the new coronavirus.
In the first experiment, two-thirds of the healthy hamsters were infected after seven days.
That compared with just one-sixth of the healthy hamsters getting infected in the second setting and one-third in the third setting, where a mask was used to cover either group.
Professor Yuen said while the test on hamsters have proven just how effective face masks are in the fight against the Covid-19 pandemic, humans should take heed of that and be prepared to keep wearing masks for the time being.
"If you are susceptible... you don't have immunity, you wear a mask, there are still some degree of protection. So that's the basis why we all should wear a mask, until you have an effective anti-viral treatment or a vaccine which is freely available," he said.
Professor Yuen added that they have also examined the symptoms and viral load of the hamsters infected with the virus, and found that those which had mask protection suffered from a less severe condition than those with no protection whatsoever.
Professor Yuen, who has been advising the government on the coronavirus situation, said now is not the time to discuss whether Hong Kong could ease some of its border restrictions against the mainland because the city hasn't done extensive testing.
Asked whether the government should relax a ban on gatherings of more than eight people, which expires on Thursday, Professor Yuen said a cluster of infections with an unknown source that was reported recently, along with inadequate testing, showed Hong Kong isn't ready for relaxing the ban yet.
"Our number of testing is even more interior to Macau's," Professor Yuen said. "Macau is testing 6,000 today... so if you don't have extensive testing, you still have a cluster with the source unknown, is it a wise thing to do stopping all these gathering measures and without even considering asking everybody to wear a mask? I think that is relatively inadvisable."