Authorities say a total of 326 people came in contact with a Thai woman in Chiang Mai who was diagnosed with Covid-19 and had visited a karaoke bar, a shopping mall and movie theatre and used public transport and Grab car services.
The revelation prompted an order by Chiang Mai governor Charoenrith Sa-nguansat for all affected venues to be disinfected, including the Central Festival Chiangmai shopping centre, which closed at 4pm on Saturday for a “big cleaning”. It will reopen at the normal time on Sunday.
Central Pattana Plc, the mall operator, said those who had been in contact with the woman while she was in the mall had been contacted by authorities and would proceed to a 14-day quarantine in line with protocols.
Officials from the Disease Control Department provided in-depth details about the woman’s movements at a briefing on Saturday as part of the contact-tracing exercise.
The 29-year-old Thai returnee from Myanmar was the only local case among five new coronavirus infections reported earlier in the day.
Dr Sopon Liamsirithavorn, director of the Communicable Diseases Division, said the woman is believed have become infected while in Myanmar. Drawing on the investigation by health workers, he presented the following timeline:
- From Oct 24 to Nov 23, the woman was in Myanmar. On Nov 23, she developed a fever, watery diarrhoea and lost her sense of smell.
- On Nov 24, she still had a fever, and developed a cough and a headache. Around 5am on that day, she travelled from Myanmar to Mae Sai district of Chiang Rai by public van.
- Around 11am on Nov 24, she left Chiang Rai for Chiang Mai by bus.
- At 2.51pm the same day, the woman arrived at her condominium in a Grab car. That night, she used another Grab car to visit a karaoke bar in the Santitham area with two friends. They smoked a cigarette and shared it.
- On Nov 25, she stayed overnight at a condominium with one of the friends who had returned from the entertainment venue around 2am. Two other friends who lived in the room opposite came to the room to drink alcohol.
- About noon on Nov 25, the woman left the condominium in another Grab car. She arrived at her condo building at around 1pm.
- Between 3.30pm and 8.30pm, she used another Grab car to visit a shopping mall and watched a movie there, had meals and went shopping. She wore a face mask most of the time. She later used another Grab car to return to her condominium.
- On Nov 26, the woman took a Grab car to a private hospital in Chiang Mai for a medical check-up around 3.30pm after she lost her sense of smell, had watery diarrhoea and a body temperature of 36.9C. She underwent a Covid-19 test.
- Around 10pm, she was sent to Nakornping Hospital for another Covid-19 test. On Nov 27, the tests turned out positive.
Of the 326 people who came in contact with the woman, 105 were deemed at high risk of infection and 149 low risk. Officials said 72 people were in close contact with her.
Questions had been raised about why the woman was not quarantined after returning from Myanmar. However, health authorities said they suspected the woman might have entered the country illegally.