Tests show key turning point on seventh dayTop News | Maisy Mok 1 Apr 2020
An animal experiment has shown that the seventh day of coronavirus infections is a turning point, top microbiologist Yuen Kwok-yung said yesterday.
Yuen and his University of Hong Kong team developed a hamster experiment modeled after humans and results showed that the viral load decreased on the seventh day as they developed antibodies.
In view of the study's results, Yuen suggested that if there are insufficient isolation facilities, young and healthy patients can be moved to second-line isolation wards on the seventh day.
The experiment's 45 Golden Syrian hamster subjects initially saw symptoms like heavy breathing and lymph atrophy, but developed a high concentration of neutralizing antibodies on the seventh day, continuing to the fourteenth day.
"We took their blood serum from day fourteen and gave it to other new hamsters those hamsters with neutralizing antibodies showed lower viral loads than hamsters without," said Jasper Chan Fuk-woo, clinical assistant professor.
Meanwhile, infectious disease expert Ho Pak-leung yesterday warned that cough droplets can travel up to eight meters in humid weather, citing findings by Massachusetts Institute of Technology researchers.
The study published in The Journal of the American Medical Association last week found that Covid-19 droplets ejected from coughs in the form of a puff-like gas cloud could reach a distance of seven to eight meters in a hot and moist environment.
Ho suggested people order takeouts instead of dining in to decrease chances of contamination, especially in poorly-ventilated eateries.
"Even if dining in, you should avoid talking once you take off the mask," he said yesterday.
He added that Hong Kong's high humidity also means that droplets can travel like "the speed of a race car" at 30 meters per second.
He also called for greater transparency in testing results and the number of cases at each hospital so scientific preventive measures can be taken.