For the migrant worker situation, I anticipate it will take another three to four weeks to reduce significantly," said Professor Teo Yik Yang, dean of the National University of Singapore's School of Public Health.
He pointed to the virus' reproduction rate -- meaning how many people infect each other. A rate of 1 means each infected person transmits the virus to one other person.
"If we start off with a base infection of 1,000 cases, even if we manage to bring down the reproductive rate to just 0.5, it will still take six to seven infection cycles (or serial intervals, each of four to five days), before we bring a base number of 1,000 down to single digits," he said.