Covid-19 cases rose 12.8% last week over the previous week, mostly in Greater Bangkok and tourist provinces in the East and the South, according to health authorities.
Tares Krassanairawiwong, directory-general of the Department of Disease Control, said on Sunday that the number of seriously ill patients increased slightly while the number of covid-related deaths was stable.
It had been expected there would be small waves after Covid-19 was redefined as a communicable disease under surveillance on Oct 1, he said.
"The number of patients admitted to hospitals rose in Greater Bangkok and tourist provinces, especially in the East and the South where there are more Thai and foreign tourists as well as crowd activities," Dr Tares said.
From Nov 6-12, most patients dependent on ventilators were either unvaccinated or had not had a booster shot, he said.
Last week, there were 3,166 new Covid-19 patients admitted to hospitals (an average 452 a day) and 42 fatalities (average six per day). On Nov 12, there were 329 patients with lung inflammation and 178 dependent on ventilators.
Dr Sophon Iamsirithaworn, deputy director-general of the Department of Disease Control, warned unvaccinated elderly people to stay at home and family members who visit entertainment places or other aras at risk of contracting Covid-19 to stay away from elderly relatives.