We are getting loads of questions on testing (especially antibody tests). Who’s reliable, who isn’t? And the price points can vary WIDELY.
As far as validation goes, there are two places to watch:
- The COVID-19 Testing Project This group is a a multidisciplinary team of researchers and physicians at UCSF, UC Berkeley, Chan Zuckerberg Biohub, and Innovative Genomics Institute. Their findings are already available on MedRXiv.org preprint, and there is a clear discussion of their validation process (ie- where they got COVID blood, where they got controls, etc).
- FINDDx.Org is a WHO-affiliated not for profit organization also validating testing- both molecular and immunoassays. This is is also a great resource. Many molecular tests have been validated. You’ll see the results are very good. It’s the collection process that makes the PCR testing less reliable, unfortunatley. The immunoassay validation is just starting, so check in at the site frequently. You can see the list of tests scheduled to go throug validation. According to KBMO, they are on the list (recall that KBMO is distributing a test made and extensively used in China. It’s a colloidal gold assay, and you’ll see there are a few listed on the site.)
What about the specialty tests that are marketed to us in FxMed? Talk to the company and get the details on how they developed the test, or if they are using a kit, get those details. I am inclined to support smaller labs, but we must be sure they are reliable.
Dr. Helen Messier wrote up a nice white paper on lab testing. Access it here. Note that she mentions the specific proteins that are most reliably used in an immunoassay. Confirm your lab is using those.
Some pitfalls to look out for:
– Many in-house tests developed for the first time by labs use limited sample sizes, or ‘spiked’ samples, to determine sensitivity and specificity. This means that sensitivity and specificity can be reported as high even though the underlying data pool isn’t that robust. What do they use for control blood?
– FDA approval isn’t much to go on at the moment- (although apparently that’s about to change). Thus far, new rules mean that SARS CoV-2 tests need only register with the FDA for ‘FDA approval’. The FDA is not evaluating these tests.