In a Facebook post on Thursday (August 20), he listed the possibilities as follows:
• The incubation period of the Covid-19 virus is usually two to seven days, but can also take as long as 14 to 21 days. “So, those who have already undergone 14-days quarantine are advised to self-isolate themselves for another 14 days to ensure they don’t spread the disease,” he said.
• People may get infected while undergoing quarantine in facilities, such as a cruise ship. “Hence, we will have to prevent people who have undergone quarantine in state facilities from coming into contact with others,” he said.
• There is still a small possibility of Covid-19 infection in Thailand. “Though this possibility is slim because Thailand has been free of local Covid-19 for more than 80 days, it can still happen,” he said.
• There is a possibility that the patient has been infected from overseas, and they may carry a small amount of genetic viral material that is difficult to detect. “After the patient arrives in Thailand, they may test negative at first but turn positive later as was seen at the start of the outbreak,” he said.
The virologist said in a study conducted on 212 patients, he found that 6.6 per cent of them showed symptoms four to 12 weeks after they were allowed to return home.
“However, the virus was very weak, so the possibility of spreading the disease to others is very low,” he added.