RT-PCR coronavirus tests cleared 90 students and teachers at Khamsoipitthayasan School in Mukdahan of Covid-19 infection suspected after earlier antigen tests.
Improper handling and storage of the antigen test kits were blamed for them returning false positives.
The students and teachers had been quarantined at a field hospital in Wat Phu Dan Tae after their antigen tests returned positive for Covid-19. The first tests were conducted on 1,202 students and 72 teachers after the communicable disease committee of Mukdahan had announced a coronavirus outbreak at the school.
The quarantined people underwent RT-PCR tests at 7 a.m. and all their repeated tests returned negative. Everyone was discharged from the field hospital and officials will later explain the wrong results from the first round of antigen tests.
However, parents, teachers and students were advised to monitor their health conditions. If they cough or have a fever, runny nose, sore throat or breathing difficulty, they must alert health officials at once.
Dr. Chakkarat Pittayawong-anont, director of the Bureau of Epidemiology, said that antigen test kits could produce false results and local officials had yet to clarify the issue.
He said that if students were infected, school management could close only their class and would not have to close a whole school.