As Singapore ramps up Covid-19 testing, with plans to ease even more work and social restrictions, it would be useful to also start screening transport workers, cashiers and others on the front line, experts said.
Widespread testing is key, not just to identify and isolate those infected, but also to obtain important data.
This includes the proportion of those infected who are asymptomatic and where transmission has occurred, allowing for precautionary measures to be targeted, said Associate Professor Josip Car, director of the Centre for Population Health Sciences at Nanyang Technological University's Lee Kong Chian School of Medicine.
Professor Teo Yik Ying, dean of National University of Singapore's (NUS) Saw Swee Hock School of Public Health, suggested that transport workers like bus drivers and those providing public services like cleaners should be tested.
This is important given that more people are now taking the trains and buses, he said.
Associate Professor Alex Cook, vice-dean of research at the NUS Saw Swee Hock School of Public Health, said: "Another group worth considering are people in retail, like cashiers at supermarkets, who have been working on the front lines from the circuit breaker and into phase one."
Prof Teo also stressed the importance of routine testing because someone who has been infected may get it again.
Prof Car said: "I am hopeful that with time, we will not only test but test repeatedly, at feasible intervals, vulnerable groups and those in contact with them... and also workers with high levels of social interaction such as those in the service sector like food and beverage, wellness and entertainment."
Foreign workers are now tested before they are allowed to return to work, and once every two weeks after that.
Apart from foreign workers, staff and residents of senior homes, pre-school staff and healthcare workers have also been tested.
More recently, testing was expanded to also include students and school staff diagnosed with acute respiratory infection at first presentation to a doctor.