A total of 152,794 migrant workers residing in dorms have returned positive results in PCR or serology tests for Covid-19. Approximately 323,000 migrant workers are living in dormitories across Singapore, the statement added.
PCR tests are used to diagnose current or new infections, the ministry said, while serology tests can detect the presence of Covid-19 antibodies in blood samples and allow health officials to identify people who had been infected in the past.
The vast majority of migrant workers who returned positive results were either asymptomatic or had very mild symptoms, it added.
The new statistics show that the number of infections in Singapore was much higher than previously thought.
"For every Covid-19 infection in the dormitories detected through PCR testing, another 1.8 cases were untested and undetected at the time, and were identified subsequently only through serology testing," the ministry said.
"This is not surprising as many migrant workers did not have any symptoms, and thus would not have sought treatment."
As of Wednesday, Singapore reported 58,341 cases and 29 deaths since the pandemic began.
The majority of those cases were reported in migrant workers' dormitories over the summer, prompting authorities to lock down the facilities and conduct testing to stem the outbreak.