Nine villages in Tak Bai district, where the first cases of the South African variant of Covid-19 were detected on Saturday, remained closed to prevent the malignant strain from spreading to other areas in Narathiwat, a senior Public Health Ministry official said on Sunday.
Disease Control Department chief Opas Karnkawinpong said nine villages in tambon Koh Sathon were under lockdown after health authorities detected the South African variant in three people, who fully recovered from the infections.
The province had originally planned the lockdown only from May 8 to Saturday but Dr Opas said the restrictions were still being enforced in the nine villages.
The South African variant, which carries one mutation that makes it more contagious and another that might make vaccines less efficacious against it, was reported on Saturday in tambon Koh Sathon of the border town.
An investigation by the department found the strain was imported into Thailand by a Malaysian woman who illegally crossed the border to Thailand with her son and mother-in-law to visit her husband in Tak Bai from April 12-May 4.
Aside from the 32-year-old man, details remained sketchy about the other three people infected with the B.1.351 strain. The man's wife had already returned to Malaysia.
“The South African variant detected in Tak Bai was similar to that found in Malaysia,” the department chief said.
The first person found infected with the South African variant was a Thai national who returned from Tanzania in February. The cases in Tak Bai were believed to be first local transmission of the strain.
“We are paying attention to this strain due to its better resistance to vaccines compared to other strains,” Dr Opas said, stressing the importance of inoculations to reduce the chance of infections.
Taweesilp Visanuyothin, the spokesman for the Centre for Covid-19 Situation Administration, said authorities along the border with Malaysia had been ordered to stiffen measures, including setting up more checkpoints away from the border to catch illegal entrants as they moved further inland.
Tak Bai is opposite Kelantan state of Malaysia, with the Kolok River dividing the two countries.