A doctor has said that a 23-year-old Vietnamese man has tested positive for swine flu in what would be the first case in the Southeast Asian nation.
An initial test conducted Saturday at the tropical diseases hospital in southern Ho Chi Minh City was positive, Phan Van Tu, a doctor with the city's Pasteur Institute, told AFP.
But he said the Pasteur Institute, which specialises in testing for infectious diseases, would conduct another test on Sunday.
The patient was in a stable condition with a slight fever, Tu added.
State-linked Tuoi Tre newspaper reported that the patient is a student recently returned from the United States.
Tuoi Tre said he arrived in Ho Chi Minh City from the US Monday night and was admitted to hospital there after being checked by health authorities.
The newspaper, which did not give a source for its report, said the student later left hospital to go home but on Friday went to the tropical diseases hospital, where he tested positive for the A(H1N1) virus.
Swine flu was first detected last month in the United States and Mexico.
In its latest update the World Health Organisation said 53 countries have reported 15,510 cases of swine flu, including 99 deaths.
Vietnam has been monitoring the health of passengers arriving at its airports in a bid to detect swine flu.
Earlier this month authorities in South Korea said a 22-year-old Vietnamese woman returning home from the US was infected with A(H1N1) and placed in quarantine while on a transit stop at Incheon.
Vietnam has the world's second-highest death toll from bird flu, at 56.
Preventing swine flu from infecting patients sick with the deadly H5N1 avian flu should be a top priority, especially in Asia, experts have said.