Thailand is expected to observe a clearer picture of how the highly transmissible BA.4 and BA.5 sub-variants of Omicron are spreading in the kingdom in the coming weeks, experts say.
The actual number of new Covid-19 infections is estimated to be more than 10 times the figures recorded daily, they say.
The number of patients found to have Covid-19 upon being admitted to Siriraj Hospital for treatment is rising steadily even though the number of Covid-19 patients with severe symptoms isn't increasing significantly, said Dr Prasit Watanapa, dean of the Faculty of Medicine at Siriraj.
The clear rise in the hospital bed occupancy rate at Siriraj, the country's oldest teaching hospital, has prompted the hospital to prepare to deal with a larger number of new Covid-19 patients to come, he said.
These patients seek treatment for worsening symptoms of their chronic diseases but as Covid-19 testing is normally required before they are admitted for treatment, many were found to have Covid-19 as well, he said.
This is a concern especially now that the highly transmissible BA.4 and BA.5 sub-variant of Omicron is spreading and a higher number of infections with these particular strains has been reported, he said.
''A clearer picture of how the BA.4 and BA.5 spreading situation in the country will be observed in the next couple of weeks, even though the strains have been spreading in Europe for several months already,'' he said.
Europe records about 10,000 new cases of BA.4 and BA.5 every day and these sub-variants are replacing the BA.2 sub-variant as the dominant variants, while there still is insufficient evidence to say whether these new strains are more virulent, he said.
Because several countries in Europe have dropped Covid-19 testing, the actual number of new infections per day could be a lot higher than the 10,000 new cases detected each day, he said. "As Thailand has fully reopened for visitors and now receiving about 10,000 arrivals per day, the spread of the coronavirus could intensify," he said.
Getting regular booster shots of the Covid-19 vaccine is highly recommended especially among at-risk groups, he said. "The people with an underlying medical condition and the elderly are advised to get a booster shot every four months," he said.
A recent study by the Ministry of Public Health among a sample of more than 500,000 people found a third booster shot helps cut the risk of Covid-19 infection by 30%, while a fourth booster shot cut the risk by 70% to 75%, he said.
Wearing face masks, social distancing and washing hands are still necessary for everyone to protect themselves from getting the coronavirus, no matter which sub-variant it is, he said. Long Covid is real and may strike any infected patients regardless of what sub-variant they have, he said.
The possibility of BA.4 and BA.5 resulting in a new wave of Covid-19 as happened when the Delta variant dominated new infections in Thailand is unlikely as vaccination coverage is now high and the people have learned and become more vigilant against infection, he said.
Dr Yong Poovorawan, a clinical virologist with the Department of Paediatrics at Chulalongkorn University's Faculty of Medicine, said the number of child patients infected with Covid-19 is rising. In a recent Facebook post, he said he had been notified of about 10 infection clusters in the same families in a single morning.
However, this infection situation appears to match the regular flu season, which usually begins in July and January of every year and coincides with the beginning of a new school term, he said. The actual number of new Covid-19 infections could now be more than 10 times the number reported, he said.
A study by his department showed about half the child patients were found in a blood test to have been infected with Covid-19 without showing any symptoms, he said.
