Vietnam plans to test all 13 million residents of its most populous city Ho Chi Minh amid the discovery of a worrying coronavirus variant and a surge in infections.

After a month with no community transmissions, and widespread praise for its handling of the pandemic, local cases have spiked with 4000 infections since April 27.

Vietnam still has one of the world’s lowest tallies from the pandemic, with just 47 deaths – and authorities seem determined to keep it that way.

Ho Chi Minh City expects to test 100,000 people each day in an urgent mass testing program, said city chairman Nguyen Thanh Phong during an emergency meeting on Sunday, according to online newspaper VnExpress.

The news follows an announcement earlier on Sunday that Ho Chi Minh City would impose a two-week period of social distancing on Monday for the first time since April 2020.

The decision came after the city found more than 100 new virus cases, linked to a Christian mission cluster that emerged on May 26, with the source of transmission unknown.

Citywide restrictions ban gatherings of 10 people or more outside of workplaces and hospitals and enforce a two-metre social distancing rule.

The Ministry of Health on Saturday said it had detected a new COVID-19 variant comprising characteristics from the British and Indian strains of the virus.

Nguyen Thanh Long, Vietnam’s minister of health, said the hybrid variant, which is highly transmissible through air, was detected through genetic sequencing on COVID-19 patients in Vietnam.

Vietnam has officially recorded 7107 coronavirus cases and 47 deaths since the pandemic began.

13 million Vietnamese in Ho Chi Minh will be required to social distance. Photo: Getty

Social distancing in a city of 13 million

Ho Chi Minh City, which is Vietnam’s business hub, will begin social distancing measures for 15 days from May 31 to curb the spread of the virus.

“All events that gather more than 10 people in public are banned city-wide, but the city is considering to lower the number of people to just five,” the government said.

Go Vap district, where the Revival Ekklesia Mission is located, will be under full restrictions, and people there will not be allowed to go out unnecessarily, the statement said.

On Friday, Ho Chi Minh City shut shops, restaurants and other services, and suspended religious activities until further notice.

People 60 or older have been encouraged to stay home.

-with AAP