The Department of Disease Control has advised the Centre for Covid-19 Situation Administration (CCSA) to reduce the quarantine period for returnees from 14 to 10 days.
The department will formally submit the recommendation to the CCSA's sub-committee tasked to oversee quarantining at a meeting next week.
The sub-committee then will forward the advice to the main body of the CCSA which will make a decision by the end of this month.
If the CCSA approves the recommendation, the new quarantine duration is expected to be implemented next month, according to Dr Opas Karnkawinpong, director-general of the DDC.
The recommendation is based on the department's monitoring of foreigners and returnees to Thailand, as well as research from Switzerland and the country's own quarantine situation.
Dr Sophon Iamsirithavorn, chief of the Communicable Disease Division, said that four days less of quarantine would not affect the efficacy of Thailand's coronavirus prevention measures.
"It is obvious that there is no difference between 10 or 14 quarantine days with visitors who come from countries with very low rates of infection," Dr Sophon told the media in a press briefing yesterday at the Public Health Ministry.
The results show the most effective time for controlling infection is from one to 10 days, and lower afterwards.
He further explained that, in Thailand, it found that the percentage of Covid-19 infected returnees from China, Australia and Taiwan is 0.04%; in Australia it is 0.48% and New Zealand it is 0.1%.
The average infection rate of infected returnees is 0.63%.
In contrast, the number of infections is very high, at 5%, among returnees from Kuwait, Sudan and Saudi Arabia.
As of April this year to date, there have been 116,219 returnees under the state quarantine system.
In other news, health officials in Tak province on Friday found two Thais had been infected with coronavirus.
These villagers are among the 4,600 local people who were summoned to take Covid-10 tests because they had been in contact with Myanmar drivers who tested positive for the deadly virus last week.