SINGAPORE — In the first 12 hours since a new swab test for Covid-19 was introduced at Singapore’s land, air and sea immigration checkpoints, the authorities have tested one traveller, the Home Team under the Ministry of Home Affairs said.

The swab test, which was announced by the Ministry of Health (MOH) on Tuesday, has an accuracy of more than 99 per cent and produces a result within three hours, the Home Team Science and Technology Agency (HTX) said on Thursday (March 5).

A collaboration between Home Team HTX and Veredus Laboratories, this new test kit is faster than hospital-run tests, which can typically take seven hours to complete.

TODAY takes a closer look at how the new swab tests work and what happens when a person is required to take one.

WHAT IS THE PROCEDURE FOR A TEST?

MOH said that the swab test is meant to cover travellers entering Singapore who exhibit fever or symptoms of respiratory illness but do not meet the “clinical suspect case definition”.

As before, persons crossing through Singapore’s checkpoints will be temperature-screened by healthcare assistants. If a traveller is found to have a fever, they may be escorted by checkpoint officers to a health screening station, the Immigration and Checkpoints Authority (ICA) said.

There, on-site nurses will assess whether the person must undergo a swab test by checking their travel history among other factors.

Should the nurses decide it is necessary for the traveller to take a swab test, samples will be taken from each of the person's nostrils. The person will also have to submit his or her contact details.

The traveller will then be permitted to proceed through the rest of the immigration process, but must remain contactable afterwards, or risk facing penalties and prosecution under the Infectious Diseases Act, MOH said. In a press release on March 3, MOH said that it would contact individuals regarding their swab test results and those who test positive will be conveyed to the hospital in a dedicated ambulance.

While the traveller continues with their journey, the test sample will be transported to a laboratory at the Pasir Panjang Screening Station run by Home Team HTX.

HOW DOES THE TEST KIT WORK?

HTX scientists check the sample in a three-step process.

First, they will extract the sample’s RNA (ribonucleic acid) and prepare it for analysis. Just as human genes are made of DNA (deoxyribonucleic acid), viruses such as the one that causes Covid-19 and dengue fever have genes made of RNA.

A sample of the Covid-19 test kit that is used to detect the virus. Photo: Najeer Yusof/TODAY

Scientists can therefore identify the virus by analysing the sample’s RNA. This RNA is then converted into DNA so that it can be read by the scientists’ instruments, and the sample is loaded onto a small electronic chip. This stage takes roughly 30 minutes, the scientists said.

Next, the virus in the sample is multiplied via a process known as Polymerase Chain Reaction (PCR), which serves to amplify the signal of the virus so that it becomes more detectable.

Ms May Ong, the director of Home Team HTX’s chemicals, biological, radiological, nuclear, and explosives department explained that it was akin to initially having one football in a football field, and then multiplying the footballs to make them more noticeable.

This stage makes up the bulk of the process, and takes two-and-a-half hours to complete.

The third and final stage involves reading the analysis results via a programme built into the electronic chip. The results will then be relayed to MOH.

An electronic chip used to load the virus sample in order to screen the test samples taken from individuals. Photo: Najeer Yusof/TODAY

In total, the entire process takes three hours to complete, excluding the time needed to transport the sample from the checkpoint to the laboratory.

Because this test checks only for the presence of the Covid-19 virus, it is much faster than those tests deployed at hospitals, which also check for the severity of the infection.

“This is a rapid screening process to detect and intercept threats coming into Singapore,” Ms Ong said.

In the future, the test kit’s capabilities may also be extended to include testing for the Middle East respiratory syndrome that had an outbreak in 2012, Home Team HTX said in an information sheet.