Everything you need to know about the different types of Covid-19 tests and whether they are covered by medical aid schemes.
As South Africa finds itself starting to move out of the second wave of a Covid-19 outbreak, over 8 million tests have been carried out in the public and private sector since the start of the pandemic.
The global gold standard method to diagnose Covid is the reverse transcription polymerase chain reaction (RT-PCR) test. It is the most accurate way to detect Sars-CoV-2, the virus that causes Covid-19.
Will your medical aid pay for the test?
According to Lee Callakoppen, principal officer of Bonitas Medical Fund, all clinically appropriate and referred diagnostic testing for suspected Covid-19 cases will be funded as a prescribed minimum benefit (PMB) condition.
Callakoppen said: “Funding is in accordance with the Council for Medical Schemes (CMS) guidelines, all clinically appropriate and referred diagnostic testing for suspected Covid-19 cases will be funded as a prescribed minimumbBenefit (PMB) condition.’
Bonitas pays for up to three Covid-19 diagnostic tests from risk, whether the result is positive or negative.
However, this is subject to the member or beneficiary being referred by a registered healthcare practitioner (doctor or nurse).
This referral is dependent upon whether the member is showing symptoms, has been in contact with anyone who has Covid-19 and prior to hospitalisation.
It should be noted that laboratories will not normally accept walk-ins for testing and require a referral or request from a healthcare practitioner.
What about Rapid Antigen Tests
Immunoassay devices that detect the Sars-CoV-2 antigen within 15-30 minutes have also been promoted as a possible solution when access to PCR tests is a challenge.
An antigen – detected in the blood or any other fluid – is any substance that makes the immune system produce antibodies. Viruses and bacteria are antigens.
However, these tests are not as accurate as the PCR tests and have shown variable performance during evaluations, with sensitivities ranging from 0 to 94%.
Test specificity has been high, but sensitivity has been erratic, which we need to bear in mind.
Why is specificity and sensitivity critical?
Sensitivity is the percentage of true positives (eg 90% sensitivity = 90% of people who have the target disease will test positive).
Specificity is the percentage of true negatives (eg 90% specificity = 90% of people who do not have the target disease will test negative).
These allow you to rule conditions in or out but not definitively diagnose a condition.
What about rapid antibody tests?
Many countries, including South Africa, are using antibody or serology tests such as the ones offered at various drive-throughs.
These can detect whether someone has previously been infected and estimate how widespread the infection is but they are not recommended for diagnosis of Covid-19.
For this reason, these are not funded by medical aid as the use for these tests is limited for purposes of government surveillance and research rather than diagnosing Covid-19.
If individuals want to know whether they have previously had Covid-19, for their own information, this test would be able to confirm that – but it is not used to identify whether you currently have the infection.
If these tests are done too soon after the infection, they produce incorrect results as the antibodies (IgM and IgG) will not be detectable.
There is also no scientific evidence that it provides any immunity to another Covid infection.
“What is clear is that laboratory testing plays a vital role in the diagnosis and the prevention of the spread of the virus,” said Callakoppen.
“Nevertheless, it is important to understand that the timing and correct use of the different types of tests is crucial to gain the best results.
“We reimburse up to three PCR or rapid antigen tests done in or out of hospital for our members and recommend that this protocol for testing remains, until further research is conducted and evidence provided.”