Antigen tests for SARS-CoV-2 detection will be rolled out to all ports of entry in South Africa with immediate effect, the South African government has announced.

It noted in an October 9 statement that the purpose of this was to effect the provisions of lockdown Alert Level 1 travel regulations, which stipulate that all travellers that arrive at a port of entry without a certified negative SARS-CoV-2 polymerase chain reaction (PCR) test result (not older than 72 hours) must be tested at the point of entry.

Antigen tests, which are different from antibody tests, are immunoassays that detect the presence of a specific viral antigen, which implies current viral infection. The advantage of the antigen test is that, unlike the PCR test, the results are available in 15 minutes, the government informed.

In consideration of the logistical complications that a point of entry PCR test poses and the additional mitigation measures in place, it was resolved by Cabinet to implement testing at points of entry using the antigen test.

Government noted that it was also aware that some of the country’s neighbouring countries, for example Lesotho, did not have the capacity to conduct PCR testing for all travellers destined for South Africa.

Antigen testing will therefore enable the management of  the influx of travellers without certified PCR tests timeously, it posited.

An additional consideration for government was the cost effectiveness of the exercise – at a fee of about R150 to R170, antigen tests cost much less than PCR tests.

“Government wishes to emphasise to all travellers that the cost of the antigen test shall be borne by the traveller and not South Africa or their country of origin. Travellers are implored to ensure that they make the necessary arrangements to be able to effect payment at the point of entry,” it said.

The World Health Organisation has recently approved the use of rapid antigen tests as a point of care diagnostic for Covid-19 screening and surveillance where a rapid result is required at low cost.

Rapid antigen tests have been commonly used in the diagnosis of respiratory pathogens, including influenza viruses and respiratory syncytial virus, noted government.

The South African Health Products Regulatory Authority has granted emergency use authorisation for two companies to supply antigen tests. There is anticipation that more of these tests will become available from other suppliers. The National Health Laboratory Service will be procuring these tests initially for use at the ports of entry.

In time, as more kits become available, these tests will be rolled out in community surveillance programmes.

The antigen test is conducted by collecting a sample from the naso-oropharyngeal area, in the same manner as a PCR test and, therefore, sample collection must be done by a professional and cannot be done by an individual at home.

Government emphasised that it was important to be aware that the PCR test remains the gold standard, given that it has much higher sensitivity and specificity than the rapid antigen test.

It implored all travellers to adhere to the regulations and ensure that, where possible, they complete processing their PCR tests not more than 72 hours prior to their departure or arrival at a port of entry in South Africa.

In the event of a traveller arriving at a port of entry without a certified negative PCR test, they will follow a testing process that they will bear the costs for.