TOKYO: Japan’s health ministry has raised the level of caution against possible community infections with the omicron variant of the novel coronavirus, tightening border controls and launching screening tests for the new variant.

Two cases of infection with the omicron variant that have been found in Japan were both detected in airport quarantine checks. But experts say they cannot rule out the possibility of the variant being found in communities.

Omicron infections have been confirmed for a Namibian diplomat and a man who arrived from Peru. After both tested positive for the coronavirus in checks at Narita International Airport near Tokyo, the omicron variant was detected from them in genetic analysis by the National Institute of Infectious Diseases.

Under the health ministry’s previous rules, airplane passengers seated in the same row as an infected individual as well as those in two rows immediately in front and behind had been regarded as close contacts.

Effective on Tuesday, when the Namibian diplomat’s infection with the omicron variant was confirmed, the ministry revised the policy and designated all passengers of the plane carrying an omicron-positive individual.

The ministry made the revision out of consideration for anxiety among the people, health minister Shigeyuki Goto said, with many things not known yet about the omicron variant, including its infectiousness and the effectiveness of the existing COVID-19 vaccines.

Close contracts have to undergo a polymerase chain reaction, or PCR, test about every two days. As they are required to be isolated at designated accommodation facilities and are not allowed to go out for 14 days, the ministry can check their activities closely, an official said.

But a senior ministry official warned that it is difficult to prevent infections by border controls alone in view of the variant’s suspected strong infectiousness.

The delta variant, the main cause of the fifth wave of infections in Japan this summer, was first detected in the country from an entrant in an airport quarantine check. The delta variant subsequently spread in communities and by August, almost all coronavirus infections in Japan were said to have been attributed to the delta variant.

The quick discovery of infected people is key to preventing the spread of community infections. The health ministry has expanded the scope of infection cases that are subject to genome analysis and urged local governments to start screening tests on all coronavirus-positive people to find any infections with the omicron variant.

“Even if community infections are found, we will contain them and prevent them from spreading,” another senior ministry official said.

JIJI Press