Two of them, "Patient 52" and "Patient 149," had entered Vietnam from abroad and treated at the No.2 Hospital in Quang Ninh.

"Patient 52" is a 24-year-old woman from Quang Ninh's Ha Long Town. She had flown in from the U.K. to Vietnam on March 9 and confirmed positive with the novel coronavirus on March 14.

"Patient 149" is a 40-year-old man who lives in Hanoi's Long Bien District. He flew from Germany to Vietnam on March 23 and was confirmed positive on March 26.

Three others, "Patient 168," "Patient 188" and "Patient 231," are employees of the Truong Sinh Company, which provides food and logistics services for several hospitals in Hanoi, including the Bach Mai Hospital, a major Covid-19 hotspot. They were treated at the Ha Nam General Hospital.

"Patient 168" is a 35-year-old woman who was confirmed positive on March 28. 

"Patient 188" is a 40-year-old woman in Hanoi's Chuong My District who was confirmed positive on March 29.

"Patient 231" is a 57-year-old woman from the northern province of Bac Kan who was confirmed positive on March 4.

The Ninh Binh General Hospital announced Thursday that one of its Covid-19 patients has recovered. Though the patient has tested negative four times, the patient would continue to be monitored at the hospital in the context of some other patients having tested positive after testing negative several times, said Vu Manh Duong, director of the Ninh Binh Health Department.

Vietnam has confirmed 268 Covid-19 cases so far and discharged 177 from hospitals.