Thailand's Center for COVID-19 Situation Administration (CCSA) on Monday said that the government is on an aggressive campaign to conduct proactive COVID-19 tests on 100,000 people across the country before the end of June.

"We have already conducted saliva tests on 6,380 people, including foreign workers, retailers, public transport drivers, and medical personnel," said Dr. Opas Karnkawinpong, director-general of the Department of Medical Sciences at the Ministry of Public Health, adding "only one tested positive."

"I am very confident that the number of COVID-19 cases in the country is minimal, most new COVID-19 cases are Thais who have returned from overseas," Opas said.

Opas, who is in charge of conducting the random saliva tests nationwide, said that in Bangkok alone, 4,856 people from the target of 15,000 people have already taken the saliva test, and all tested negative.

He added that the best time to take the saliva test for COVID-19 was in the morning after waking up.

"Accuracy of the test results would be more obvious if respondents haven't brushed their teeth, use mouthwash, eat, drink, or chew gum for at least one hour before the saliva test," said Opas.

The CCSA said that despite no new domestic COVID-19 cases emerged in the last 14 days, it does not mean that there are zero infection in the country.

"The risky groups are migrant workers, frontline health workers and people clogging together and not tested yet," said the CCSA, "hence it is important that the Department of Medical Sciences continue its random saliva testing campaign to ensure we have zero infection in the country."