A Facebook message with an image of a positive check for a COVID-19 test misleadingly describes it as a positive test set and suggests that it is “preloaded with the virus”.
The post (here) shows a photo of two packages. One has a biohazard symbol and says ‘COVID-19 AG QUICK TEST DEVICE Positive control’. Text above the photo says: “Can anyone explain this ??? Why are there positive and negative test sets? And why does the positive test show that it is a bio-hazard? Is the test preloaded with the virus? ”
As part of the quality control measures for COVID-19 tests, ‘control samples’ are included in groups to detect errors.
To make sure that the test does not detect the disease in people who are not infected (called false positives), a negative control is used. It consists of generic cells that have not developed antibodies or are infected with the disease that can be carried out by the test. Medical practitioners know that these cells are not infected, so if the test comes back positive, it shows that something went wrong with the test and indicates that it should not be used.
Conversely, if viruses such as SARS-CoV-2 are not detected in the infected people in the tests, it makes little sense to use them. To test for this, a positive control is used. It is a swab that has been treated in such a way that it should give a positive result when performed through the test so that health professionals know that they are performing the test correctly.
Although these control swabs are widely used for other tests, including PCR tests (here), the Panbio ™ Covid-19 Ag Rapid Test Device, an antigen test, is the special product.
The product literature for this device (here) states: “The controls are specifically formulated and manufactured to ensure the performance of the Panbio ™ COVID-19 Ag Rapid Test Device and are used to verify the user’s ability to perform the test properly feed and interpret the results. ”It also says: ‘Good laboratory practice indicates the use of positive and negative controls to ensure that: test reagent works and that the test is performed correctly.’
The literature also states that these controls should be used when a new operator begins testing samples, at each test shipment and at “periodic intervals” determined by applicable laws and guidelines.
The tests are not ‘preloaded’ to give a result. The swabs are used to make sure that a sample test works correctly.
VERDICT
Missing context. A Facebook post shows the positive and negative controls for an antigen test.
Read more about our work to actually check social media posts.