The coronavirus spreading in Myanmar is a different strain that spreads 20% faster than the original one in Wuhan, according to Dr Prasit Watanapa, dean of the Faculty of Medicine at Siriraj Hospital.
Dr Prasit on Wednesday said around 60% of Covid-19 infections in Myanmar were caused by the G614 strain. The strain that spread in Wuhan last year was called D614.
The G614 strain has spread significantly in Western countries and is responsible for the most cases at present. "G614, which can spread faster, therefore needs a faster response," said the doctor.
Dr Prasit warned that hiding information from the authorities would make the virus situation worse and put everyone at risk.
"Only one slip can cause great damage to the country," said Dr Prasit.
He said society cannot be complacent after the recent news of vaccines being rolled out. "Don't pin your hopes on it, as it could take at least half a year for Thailand to gain access to Covid-19 vaccines," he warned.
In Tak, governor Pongrat Piromrat said the provincial communicable disease committee has allowed Thai nationals in Myanmar to return to Thailand through legal border crossings since Dec 7 in a bid to deter illegal entry -- the cause of Covid-19 transmission recently.
One border crossing which Thai returnees are allowed to use is the one at the 2nd Thai-Myanmar Friendship Bridge. Tak closed the border with Myanmar on March 21.
On Wednesday was the first day in almost two weeks that Thailand saw no local infections caused by illegal entry. Thailand recorded 25 new patients from nine countries.
In Chiang Rai, governor Prachon Pratsakul urged stranded Thais in Tachileik to visit the Township Border Committee in Myanmar to express their desire to return to Thailand.
The governor said they would not be jailed but would be fined 1,800 baht per person for illegally entering Myanmar. Once they arrived home, Thai public health officers would take care of them, he said.
Around 400 Thais have been stranded in Myanmar. Some 42 Thais who filed requests to return to Thailand travelled back through the crossing at the 2nd Thai-Myanmar Friendship Bridge on Wednesday.
Army chief Gen Narongpan Jitkaewthae said Prime Minister Prayut Chan-o-cha had instructed all military units responsible for security at the Thai-Myanmar border to step up measures by patrolling more frequently, by foot and drone, around the clock.
Thai returnees travelling back from Myanmar would not face serious punishment, Gen Narongpan said.
Director-general of the Disease Control Department Opas Kankawinphong said there were 46 confirmed cases related to infected Thai returnees from Myanmar. All were in state quarantine facilities or being treated at hospitals.
Over 5,100 at-risk people who had been in contact with the infected returnees had been tested. The only person who tested positive was a friend of the returnees and they had travelled together, said the doctor.
Director of the Division of Communicable Diseases, Sopon Iamsirithaworn, said all 55 people who had been in contact with a 51-year-old infected woman from Sing Buri had tested negative for the virus.
Passengers on Nok Air flight DD8717 -- the flight she and two of the infected returnees travelled on -- all tested negative.
Government spokesman Anucha Buraphachaisri on Wednesday said the government had the situation under control and the infected returnees were not superspreaders.
Meanwhile, the private sector in Chiang Rai has decided to delay legal action against infected returnees who illegally entered the country.
President of the Chiang Rai Chamber of Commerce, Anurat Inthon, said there were mixed opinions about whether to sue them.