First, it was seven, then it was 10 and now it's 14. But is a fortnight of quarantine or self-isolation actually enough to ensure full recovery from COVID-19? An expert virologist in Thailand believes governments across the world are very lax in their measures.

Professor Yong Poovorawan of Bangkok’s Chulalongkorn University says he'd recommend patients to self-isolate for another 14 days – meaning almost a month – to be sure the virus is gone.

The virologist, who is also a medical professor in pediatric hepatology and viral hepatitis, said he came to the conclusion after studying 212 COVID-19 cases. He outlined his takeaways in four points in a Facebook post last week.

"I found 6.6% of them showed symptoms four to 12 weeks after they were allowed to return home. We also found a virus after 36-105 days of symptoms, but very weak, so the possibility of spreading the disease to others is very low," he said.

The "hatching range" of the coronavirus in most COVID-19 cases is two to seven days, according to his observations. "It may be found up to 14 days and it may be less than 21 days," said Poovorawan.

"Therefore, those who have undergone 14-day isolation should stay under quarantine at home for another 14 days to increase confidence in prevention of disease spread," he said, adding that detection of COVID-19 after 14 days is "possible in patients."

On the COVID-19 situation in Thailand, he said there is a "limited possibility" of infection in the country as "no case has been found for over 80 days."

Thailand has reported 3,403 coronavirus cases and 58 deaths so far, with the government having extended a health emergency for another month until Sept. 30.

"There is a possibility that some patients have been infected from overseas, and they may carry a small amount of genetic viral material that is difficult to detect," he said.

"After patients arrive in Thailand, they may test negative at first but turn positive later, as was seen at the start of the outbreak."