As the numbers of swine flu cases climb, Hsu said he and his colleagues are keeping a close eye on the disease trends.
Based on his past work with the bird flu and SARS, Hsu said most infections decline in the summer months. If swine flu follows suit, then there are good signs a pandemic has been avoided.
"Looking at the trend, the flu data the flu trend should be declining in May," said Hsu. "The next few weeks should be important."