The National Hospital for Tropical Diseases, a frontline facility in the nation's Covid-fight, has been locked down since Wednesday after one of its doctors tested positive for the coronavirus.
By Thursday afternoon, authorities have recorded at least 42 coronavirus-positive cases associated with the hospital, of which 22 have been confirmed as Covid patients.
According to Hanoi's Center for Disease Control, nine of the 42 cases are from Hanoi while the other 33 are from Hai Phong and 13 northern provinces - Bac Giang, Bac Ninh, Hai Duong, Hoa Binh, Hung Yen, Lang Son, Nam Dinh, Phu Tho, Quang Ninh, Son La, Thai Binh, Vinh Phuc and Yen Bai.
The three Thai Binh cases have been transferred to the Thai Binh Province General Hospital, with their residences locked down and contact tracing commenced by local authorities, said the provincial Center for Disease Control (CDC).
Further test results are needed to tag them as Covid-19 patients.
In Hung Yen, two coronavirus-positive cases are family members of a confirmed Covid patient at the National Hospital for Tropical Diseases. Both have stayed with the Covid patient for only a night.
Vietnam is currently experiencing its fourth wave that has seen 64 community transmissions confirmed since last week in Hanoi, Da Nang and Ho Chi Minh City and the provinces of Ha Nam, Vinh Phuc, Hung Yen, Quang Nam, Dong Nai, Hai Duong, and Yen Bai.