Aggressive testing and contact tracing will improve Singapore's ability to control the spread of the coronavirus and gradually reopen the economy, said National Development Minister Lawrence Wong, noting that the authorities had spent the circuit breaker period boosting their abilities to do both.

Giving an overview of Singapore's battle with the coronavirus so far, Mr Wong yesterday said efforts have been made to make contact tracing faster, and scale up testing capacity - including testing wastewater for viral fragments, to tell if a specific group has infected people among them.

Still, he stressed that the Government needed to be very cautious in its reopening as the "vast majority of our population have not been exposed to the virus and are still vulnerable to the disease".

On contact tracing, he said the process has been sped up - for example, by expanding contact tracing teams to include personnel from the police and Singapore Armed Forces. He also pointed to technology such as the SafeEntry check-in/check-out system, the TraceTogether app as well as wearable Bluetooth devices that are being developed.

"These will work on their own without the need for a phone. You can conveniently wear or carry them around as you go about your daily activities," he said of the devices.

Meanwhile, the Government is procuring more test kits, increasing lab capacity, and recruiting and training more people to carry out swabs and take blood samples.

"In early April, we were doing about 2,000 tests a day. Now, we are able to conduct about 13,000 tests a day, and we are on track to reach 40,000 tests a day in the coming months," said Mr Wong.

He described this expanded testing capacity as "critical".

"It means that we can test higher-risk groups more extensively. We can also do more surveillance testing in the community, including those with respiratory symptoms. This will give us a faster and more accurate sense of the number of cases circulating undetected."

The authorities are also using other methods of detection, he said. "For example, we are extracting wastewater from manholes to test for viral fragments. This provides an additional indicator to tell us if a specific group, such as those living in a dormitory, have infected people amongst them.

"We are also using serology tests. These help to identify those who were previously infected but may have since recovered, and have developed antibodies in response that can help them fight the virus."

Throughout the battle with the virus, he said Singapore was determined to avoid a situation where its healthcare system became overwhelmed.

"Covid-19 is the most serious health crisis the world has faced in a century. We have all seen the devastating effects of the virus worldwide. When the outbreak gets out of control, the spike in cases can quickly overwhelm the healthcare system. Many people will not get the care they need, and the number of deaths will rise sharply," said Mr Wong in a national broadcast recorded from the National Centre for Infectious Diseases.

"Working together, we've stabilised the situation in the migrant worker dormitories. We've brought down community cases significantly. We've protected our seniors, and kept our fatality rates low."

More than 38,000 people in Singapore have been infected with the coronavirus. Many new cases are reported daily, the majority of whom are foreign workers linked to dormitories. Yesterday, the country reported 218 new cases - the lowest since April 11.

Yesterday, Mr Wong also reiterated a point he has made several times before, that Singapore is not going back to life before the circuit breaker even as it gradually reopens.

If conditions seem stable, Singapore might move into phase two before the end of the month. This would see a broader range of activities being resumed, covering nearly the whole economy. Social interactions and family visits in groups of up to five people would also be allowed.

"Externally, we are carefully easing travel restrictions and reopening our borders, by creating 'green lanes' with selected countries. These arrangements will be limited to essential travel for work reasons, and tight controls will be put in place. When conditions permit, we will extend 'green lanes' to more countries, and to non-business travellers."

He added: "But it will take a while before we see international air travel recovering in a significant way, or before we can open up for mass market travel."

As more activities resume, Singaporeans should be "mentally prepared" to see more new cases, said Mr Wong, noting that this happened in other countries emerging from their lockdowns.

"The key is whether we are able to keep community infection rates stable. If so, we can continue on the path of progressive easing."