SINGAPORE - For pre-event testing, the Ministry of Health recommends an antigen rapid test, as it is cheaper and faster than the polymerase chain reaction test.

Antigen rapid tests usually take less than 30 minutes, while a polymerase chain reaction test, though more accurate, can take up to 48 hours.

For large events requiring pre-event testing, the ministry allows organisers to arrange for antigen rapid tests for attendees at a clinic, or hire an approved test provider to conduct the tests at the event venue.

Organisers can also require attendees to go for an antigen rapid test on their own at an approved clinic.

Dr Stephen Tong, medical director at Bethesda Medical Centre, which provides antigen rapid tests, said that to conduct a large number of tests on-site, certain conditions must be met.

He said the test site will need separate areas for registration, swabbing, sample processing, waiting for results and isolating those tested positive, plus areas for staff to put on and remove medical attire, and a biohazard waste area.

The site must have a separate entrance and exit, and enough space for safe distancing.

Dr Tong estimates that 13 staff are needed to complete antigen rapid tests for 250 people in two hours, and about triple the manpower to test 750 people in the same amount of time.

The Health Ministry said on its website that pre-event testing is necessary to reduce risks of positive Covid-19 cases at events so that more activities can resume safely.

After obtaining a negative result, the test provider will issue a Covid-19 test result notice to the attendee. This must be shown with a valid photo identification to gain entry into events that require pre-event testing. The test must have been administered no more than 24 hours before the end of the event.

If the antigen rapid test is positive or invalid, this may suggest Covid-19 infection but could also be a false positive. If this happens, the Health Ministry requires a confirmatory polymerase chain reaction test as soon as possible.

Attendees should ask the organiser whether they would receive a refund if they miss the event due to a positive or invalid antigen rapid test result.