"Patient 325" had returned from Russia on Vietnam Airlines flight VN0062, landing May 13 at the Van Don Airport in the northern province of Quang Ninh. She was confirmed positive on May 24 and treated at the Hospital for Tropical Diseases in the northern province of Hai Duong.

On June 5, she was discharged after testing negative several times. She returned home in Ninh Binh, around 120 km from Hai Duong, in a private car. In Ninh Binh, she was closely monitored by the local medical center in Gia Vien District during a 14-day quarantine period.

She was tested on June 12 in quarantine and the results were confirmed positive Sunday by the Ninh Binh General Hospital, marking the second relapse.  

She had earlier been infected by the virus in Russia in April and confirmed recovered before returning to Vietnam.

She is stable at present with no symptoms - fever, cough or breathing difficulties.

Local authorities said six people, mainly her relatives, had contacted with the patient over the past days. They have tested negative and are quarantined at the medical center in Gia Vien.

So far, Vietnam has recorded 16 relapses. Doctors have said there's low chance that relapse patients would infect others.

Vietnam has gone two months without community transmission of the novel coronavirus. Of the 334 people diagnosed with Covid-19 so far, 323 have recovered and the rest are in hospital.