Seven construction workers are suspected to have been infected with two variants of coronavirus at the same time, according to the Public Health Ministry.
Tests conducted at a large Bangkok construction site showed they were infected with the Alpha and Delta variants, first found in England and India respectively, Dr Supakit Sirilak, chief of the Department of Medical Sciences, said during the ministry's daily briefing yesterday.
As of now, they remain fit and have not developed any worrisome symptoms, said Dr Supakit. He further added that co-infection does not mean a patient's symptoms are more serious than those suffering from a single strain.
"However, more cases of mixed infections could lead to a hybrid and eventually, a new variant, something we don't want to see," he said.
Of the 1,737 workers at the construction site, 1,327 tested positive. Among them, 23.3% were infected with the Alpha variant and 73.7% with Delta.
Discussing Covid-19 variants in Thailand, Dr Supakit said the highly contagious Delta was on course to becoming the dominant strain in the country, replacing Alpha.
According to tests conducted from April 1 to Friday, Alpha made up 74.1% of cases. Delta followed with 24.14% in Bangkok and 60 provinces while Beta, which was first detected in South Africa, made up 1.78%, mainly in the South. In Bangkok alone, Delta has already become the dominant strain, with 57.1% while Alpha made up the rest, he said.
Meanwhile, doctors are bewildered by a Covid-19 case in the northeastern province of Bung Kan where a man returning from Taiwan has been found to have the Beta strain which traces neither to Taiwan nor the South of Thailand. Upon the man's return to Thailand, he was placed in a state-run quarantine facility where he exhibited no Covid-19 symptoms. He became sick after being released from quarantine.