The unnamed woman from the northern province of Vinh Phuc was a company employee who had returned from China's Wuhan City, the epicenter of the outbreak, a week before the Lunar New Year festival.
She was one of eight people on a flight from Wuhan to Vietnam. Three of the passengers have already been quarantined and tested positive for the nCoV. They are being treated at the National Hospital of Tropical Diseases in Hanoi and the Thanh Hoa General Hospital.
The latest patient was in close proximity with infected people and thus had a high chance of being infected, the ministry said.
The woman has been quarantined in the National Hospital of Tropical Diseases in Hanoi's Dong Anh District and is in stable condition. Biological samples have been sent to the National Institute of Hygiene and Epidemiology for further testing.
The woman and seven other Vietnamese employees were employed by Japan-based Nihon Plast Company Limited and sent for work training in Wuhan City in Hubei Province two months ago. They returned to Vietnam on a Southern China Airlines flight (CZ8315) on January 17.
They were picked up by the company car at Hanoi's Noi Bai Airport on January 17. After a company meeting in Thien Ke Commune, Binh Son District, Vinh Phuc Province, about 18 km from the airport, she returned home in her own car with another co-worker.
Vietnam confirmed the seventh case of the nCoV infection on Sunday, who was a 73-year-old Vietnamese American visitor who transited in Wuhan for two hours before coming to stay at a hotel in Saigon's District 3. Other patients include two Chinese nationals and a hotel receptionist in Nha Trang who received them.
Vietnam's government declared the novel coronavirus an epidemic on Saturday. The country has reported 236 suspected cases with symptoms like high fever and coughing, including some people who had visited infected areas in China, as of Monday. Of them, 163 have tested negative for the virus and 73 are in quarantine pending test results.
The death toll from the epidemic had reached 362: 361 people in China and one in the Phillipines. More than 17,000 have been infected.