Vietnam said on Monday the outbreak of Severe Acute Respiratory Syndrome had been contained.
But 'the threat of SARS import through international travel is great', the health ministry said in a statement.
The country has seen 68 infections of the flu-like disease. Five people died, all of them medical workers, with the last case reported on April 8.
The World Health Organisation said on Friday if no new SARS cases emerged in Vietnam by the end of April, the country would be the first to be taken off a list of those affected.
WHO also said in a statement posted on its Web site that 'numerous rumours' of fresh Vietnam SARS cases had been reported, but were unfounded.
Experts believe early detection and fast quarantines helped to prevent the spread of the disease in Vietnam.