One-third of Covid-19 patients in Bangkok will be tested to determine whether they have been infected by the Delta coronavirus variant as the strain is expected to dominate in the capital within the next few months, according to the Department of Medical Sciences.
The department on Monday revealed that Bangkok is the largest cluster of the Delta variant, which was first detected in India, with 331 new cases being recorded last week, increasing the number of patients infected by this particular variant to 822.
For comparison, there are reportedly 2,380 cases of the Alpha variant -- which was first detected in the United Kingdom -- in Bangkok.
According to the department, 25.66% of detected cases in Bangkok last week were of the Delta variant, an increase when compared with 23.67% in the previous week. Meanwhile, Alpha strain infections declined from 76.33% to 74.31% over the same period, it said.
The Delta variant is found less in other provinces but infections are reportedly increasing from 2.58% of all accounted cases there to 5.05%, the department said, adding that the Alpha strain is still the dominant strain outside of Bangkok.
However, the department said the Alpha strain's dominance is declining.
Regarding the whole of Thailand, the department said that 12.3% of infections were of the Delta strain, up from 9.76% in April. It said that Alpha strain cases have increased from 86.31% to 89.63% over the same period.
The Delta strain was first detected in the kingdom in April among construction workers in Laksi province. The variant has raised global concern as it is 1.4 times more infectious than the original Alpha coronavirus variant and has the potential to lessen the efficacy of vaccines.
Dr Supakit Sirilak, chief of the department, said Bangkok last week broke a record after recording 331 new Delta variant infections. He said the spread had expanded beyond the construction site cluster in April.
"All figures foretell that Bangkok will eventually be dominated by the Delta [variant] in the next few months, but please don't worry," Dr Supakit said. "People should follow [containment] measures to prevent disease infection, including by rushing to get vaccinated."
Regarding the efficacy of the Sinovac vaccine, he insisted that the jab is 70.9% effective against the Alpha strain.
"Many studies found that all vaccines can reduce the chances of infection when compared with those who are not vaccinated," Dr Supakit said. "So please do not hesitate to get the vaccine."
The department recently found two cases of the Delta variant in Narathiwat province among returnees from Malaysia, making it the first case of its kind in the South.
