Dr Thanit declined to specify which “shopping centre” the woman worked at.
The woman had travelled to Prachinburi with one of her two female roommates with whom she lived with in Patong.
After the pair had arrived in Prachinburi, the roommate was confirmed as infected with COVID-19, he said.
“The PPHO was notified of the case by Prachinburi Provincial Health Office on May 8,” Dr Thanit explained.
Officials immediately tracked down the woman in Phuket, now branded as Case 225, and confirmed that she was not experiencing any signs of infection.
She also initially tested negative for the virus on May 8, Dr Thanit said.
“The woman explained that on Mar 17 she had lost the sense of taste and smell, but still had no fever. Later, those symptoms disappeared,” Dr Thanit noted, explaining why the woman had not presented herself to a doctor.
“We had her placed in quarantine at Patong Hospital as a precaution. She was tested again for the virus on May 15, and she tested positive,” he said.
Phuket health officials on May 8 also had the women’s remaining roommate in Patong immediately placed under quarantine at Patong Hospital, Dr Thanit confirmed.
The roommate has tested negative for the virus twice, but remains in quarantine at the hospital as a precaution, Dr Thanit said.
Samples from the roommate in quarantine at Patong Hospital have been sent to Ramathibodi Hospital and the Bamrasnaradura Infectious Diseases Institute, both in Bangkok, to confirm whether or not she is not infected, he added.
Similarly, samples from the four cases reported as positive in Phuket last Sunday have also been sent to Bangkok for confirmation, Dr Thanit said.
Until those results come back, their status remains unchanged as confirmed as positive, he said, adding that he expected the test results from Bangkok to be returned no later than next week.
“Currently, all four people are still in quarantine at Vachira Phuket Hospital,” he Dr Thanit said.
“There will be no decisions as to whether any areas will be placed under lockdown again until those test results have been confirmed,” he added.