There are new tests and updates everyday and we hope to update everyone as soon as we can with the most recent news on Coronavirus Covid-19 infection.
Vaccines? Work is progressing but we should not expect a vaccine for quite some time.
Testing? Yes, lots of updates this week. There are essentially 3 types of tests available. Let’s analyse them together.
PCR Swab Testing
This is the test that is carried out by the government that involves a swab into the back of the throat/nose to get a sample of the viral shedding. This test takes 2-3 days to get a result. It tells you if you are ACTIVELY having a Coronavirus infection. It doesn’t tell you if you have HAD IT IN THE PAST. For the test to work, it is very important to carry out the swab test correctly. Therefore, it is possible to get false negatives, meaning that you actively do have the virus but you weren’t able to get a good swab of the viral shredding, hence tested negative. At the clinic, we do not send the swabs out for this reason, hence all swabs are to be carried out in the clinic only by our experienced doctors.
Antibody tests, known as “IgM IgG Rapid Antibody Test” were created at the very beginning of this pandemic. Some were not very accurate at all, some were just a scam but some were acceptable (seeing that it is rather impossible to get 100%) including the ones we used from Biomedomics (Made in USA and CE marked). This antibody test (from Biomedomics) is similar to a pregnancy test kit. You need a drop of blood (finger prick) and a drop of buffer solution, results are then available in 15 minutes. This test can tell you:-
- You have never had Coronavirus
- You have had Coronavirus and have developed antibody IgG
- You have Coronavirus and still may be infectious IgM
- You have Coronavirus and starting to develop antibody IgM and IgG
Biomedomics test has: Sensitivity: 88.66%. Specificity: 90.63%
From our own experience of doing this test over the past month for private patients and NHS frontline workers, we have found it to be very reliable (the positives were definitely positive, no false positives) when we compare the results to the patient’s history and symptoms. We did though have had a few false negatives that were re-tested. This is another reason why we do not use the tests as home kits but go through results with our experienced doctors to interpret them correctly and manage appropriately.
Over the last week however, there has been significant news. We now have another option for antibody testing from Abbott which has received US FDA and UK PHE approval and is CE marked. Abbott’s Serology Test helps to detect the IgG antibody to SARS-CoV-2. Detecting these IgG antibodies will help determine if a person was previously infected with the Coronavirus.
Sensitivity: 100% Specificity:99.6%
Now, this serology test has requirements different from the finger prick test which only requires a drop of blood. The test would require about 0.6ml of blood, which is of course more than just a drop, approximately 15-20 drops, which we feel is not appropriate to be carried out at home by yourself. There are clinics that are selling them as a DIY Home Kit, we however insist that our experienced doctors take the blood for you. This is also emphasised by Abbott themselves. The test results are available after 24 hours.
The tests we have chosen to use are PHE approved, CE marked, FDA approved and tested in a CQC approved laboratory.
After today’s update, we would like to discuss the antibody test created by Roche. The test is similar to Abbott’s as it is looking for the SARS-Cov-2 IgG Antibody. The Roche test is currently not yet available and speaking directly to the laboratories, it may be available in mid to late June 2020. We will be offering the Roche Test also when it is made available here in the UK.
We hope you found our analysis useful. We will endeavour to keep you updated on the latest news. We echo the Prime Minister’s vision; stay alert, control the virus and save lives.
Dr. Terry and Team
|PCR Swab Test||Rapid Antibody Test||IgG Antibody Test|
|Test Company||BD dry swabs/Remel M4RT/Copan 321C UTM/Copan 147C||Biomedomics||
Back of throat/nose
1 drop of blood
|0.6ml of blood|
|Detects||Viral Shedding||IgM and IgG||IgG|
|Benefit||Active infection||Presence of IgG and IgM, help to show active infection||
Presence of antibody / immunity
? Immunity duration
High false negatives with inaccurate sampling
Needs careful interpretation based on history, clinical signs and symptoms, risk factors
Less accurate to a degree
Interpretation with history and symptoms improves accuracy
|Only test for antibody IgG|
|Results||48-72 hours||15 minutes||24 hours|
|When to test||Day 1-5 of symptoms onset||Anytime although best to exclude the last 7 days exposure to ‘accurately’ test for IgG or IgM||After 14 days of symptoms|