The 42-year-old woman in the northern Vinh Phuc Province met with the returning worker during the Lunar New Year holiday. She developed high fever on January 31 and has been quarantined at a local medical center. Her conditions are now stable.

The returning worker, 23, was among a group of eight employees of Japan-based Nihon Plast Company Limited 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 and attended a company meeting in Thien Ke Commune, Binh Son District, Vinh Phuc Province, about 18 km from the airport.

Five of them have been confirmed to be infected with the 2019 novel coronavirus.

Other infection cases in Vietnam are a Vietnamese American visitor who transited in Wuhan, a Chinese man from Wuhan and his son who met him in Vietnam, and a hotel receptionist who served the father and son in Nha Trang.

By Tuesday afternoon, Vietnam have discharged three of the nCoV patients from hospital: the Nha Trang hotel staff, the Chinese son, and one of the workers coming back from Wuhan.

Vietnam's government declared the novel coronavirus an epidemic on Saturday. The country has reported 304 suspected cases with symptoms like high fever and coughing, including some people who had visited infected areas in China, as of Monday. Of them, 214 have tested negative for the virus and 90 are in quarantine pending test results.

The death toll from the epidemic has reached 427, with 425 dying in China, one in the Philippines and one in Hong Kong.