The BMA conducts active case finding in a construction camp following the closure order taking effect on Monday onwards. Credit: BMA

Delta variant could take over infections in Bangkok from Alpha variant in the next two months: DMS

The Department of Medical Sciences has spotted a sharp increase in the infection rate of the Delta variant in the city over the past week whereas the latest variant of Bata has emerged in the city

Dr. Supakit Sirirak, DMS’s Director-General, held the press conference yesterday to reveal the latest lab results from his department, which has been helping trace and verify the variants in clusters nationwide.

According to the lab test results, the Delta variant from India, which showed itself up for the first time in the city in late May in one construction camp in the Lak Si area, has demonstrated an exceptionally increasing infection rate in the city over the past week, with the rate over 32.39%, compared with 67.51% of the Alpha variant, according to Dr. Supakit.

Of 1,022 samples, and 459 Delta infected patients reported over the period, 311 were patients in Bangkok, the doctor said.

“If the trend continues like this, the Delta variant could take over the Alpha one in the city within the next two months,” said Dr. Sirikit.

The Delta variant was first reported in a construction camp in the Lak Si area around May 21, when 36 construction workers out of 80 had been tested positive with the variant. The virus has since spread both in the city and in upcountry with the speed reported to be ever faster than the Alpha one from the UK, which was first reported in an entertainment club in the Thong Lor area in late March, when the country was still struggling with the second wave of the outbreaks. Read: First local cases of contagious Indian variant discovered among construction workers in Lak Si

According to the department, since the third wave of the outbreak in April, the Delta has shown an inclining infection rate in the city, from around 23.67% recorded on June 13 to 25.66% two weeks later, or June 27. Meanwhile, the infection rate of the Alpha variant over the same period has shown a declining trend in the city, from 76.33%  to 74.31%.

In the upcountry, the infection rates of these two variants over the same period have demonstrated a similar trend. While infection by the Delta variant since April has increased from 2.58% as reported on June 13 to 5.05% on June 27. The Alpha variant, in contrast, has shown a declining infection rate, from 96.52% to 92.82%.

Nationwide, the infection rates from these variants over the same period have also shown the trend similarly. While infection by the Delta variant since April has increased from 9.76% reported on June 13 to 12.30% on June 27. The Alpha variant, meanwhile, has shown a declining infection rate, from 89.93% to 86.31%, according to Dr. Sirikit.

“It’s hard to trace the variant of Delta now. But most cases in the upcountry are still related to construction camps in Bangkok. If more people return home, we may have to find measures to handle the situation,” Dr. Sirikit said of the fresh order to close construction camps in the city, which has triggered a flood of workers returning to their hometowns.

Besides these two variants, the latest variant reported in the country, the Beta, originally reported in South Africa but was believed to have spilt over from the Thai-Malaysian border to Narathiwat and then spread to some more ten Southern provinces, has shown an increasing infection trend, with the rate of 0.61% on June 13 to 1.39% on June 27.

In conclusion, up to 7,859 Alpha infected patients have been tested and confirmed by the department since April, 1,120 more are Delta (459 jumping over the past week from 661 previously recorded), and 127 Beta ( 89 cases jumping over the past week from 38 previously recorded).

I BMA officials mobilise forces to inspect construction camps around the city following the closure order taking effect on Monday onwards. Credit: BMA

Beta in town

And as of Friday, the Beta variant was first reported in the city of Bangkok.

Dr. Sirikit revealed that a worker in one market was visited by his son who had travelled from Narathiwat province, where the Beta is spreading, and his case was confirmed on Friday after his son had fallen sick and been tested positive to the variant.

Both are under care now, the doctor said, while adding two more relatives have their health examined and are waiting for the lab results. Some other six or seven colleagues of the man were tested negative to the virus, the doctor added.

Dr. Sirikit tried to allay the public fears over the discovery of the variant in the city, saying concerned authorities can stem it if there is only one case. However, he did not rule out the possibility of further spread of the variant.

“Because we don’t ban inter-provincial travels, so there is a chance (of the spread of the variant). But the variant is not fast-spreading, we are rather concerned about the Delta variant, of which infection rate is increasing,” said Dr. Sirikit, adding people can practice personal disease control measures against the variant as normal, but if vaccines are available, they should immediately get a jab.

Credit: DMS

His department has also confirmed the effectiveness of China’s Sinovac vaccine, which has largely been given to the people, saying the data taken from real cases, or the real-world data, has demonstrated that two doses of the vaccine given within 14 days showed around 82 to 90.7% effective against the Alpha variant, or 71% on average.

However, he has not yet confirmed the effectiveness in symptomatic protection against the Delta or Beta variants, saying the department needs to collect more data from real cases, which are still relatively small to demonstrate results.

“We have learned that the Beta variant can elude vaccines, but there is no reliable evidence to have confirmed its virulence yet,” said Dr. Sirikit.

As of yesterday, the Center for Covid-19 Situation Administration (CCSA) reported that the Beta cluster from a religious school in Narathiwat has spread to 12 provinces in total, with 643 cases reported in total.