“False Positive” Tests – Discordance Between Antigen and PCR Tests: Update
Regulation | September 17, 2020 | by Ruth Katz
Starting last week, we heard concerning reports of discordance between the antigen tests and PCR confirmation test results (e.g. potential false positives) from the antigen testing machines HHS has sent to nursing homes. To better understand what’s going on across the country, LeadingAge and AHCA collaborated on a survey to understand the use of the BD Veritor and Quidel Sofia-2 Antigen Point of Care analyzers in member communities.
We heard back from over 1,100 respondents, approximately 939 of whom are using either the BD or Quidel analyzers (thank you for responding). We found that about 20-25% of SNFs had a positive antigen test result later found to be incorrect using PCR testing. The vast majority had only 1-3 “potential false positives”; 26 (or 3%) had more than 5 false positives. While any false positive results are concerning, this appears to be consistent with what you would expect to see with widespread testing of many people in communities with relative low rates of COVID-19. Nonetheless BD and Quidel are investigating to make sure there are no issues. Preliminary investigation from a few reports received last week have not revealed any abnormalities. Its important for all providers to double check they are following the manufacturers protocols and have staff appropriately trained on the use of each analyzer.
We continue to ask you to report false positives to the manufactures:
For BD Veritor false positives providers should
- Call 1-800-638-8663 fr providers who experience false positives (nte: press 2 for technical support and then 1 for Veritor support); r
- email BD at Technical_Services@bd.com
- BD ffers this micrsite and these training webinars which we encurage members to review if they are having concerns with accuracy to make sure they are following all the instructions correctly.
For Quidel false positives, providers should
- Call 800.874.1517, ption 2, then option 1 who experience false positives
- email Quidel at Technical Supprt (Quidel San Diego) email@example.com
- Visit tgetheragain.quidel.com t view nline training mdules
- Quidel ffers live training seminars every Tuesday and Thursday at 12 P.M. EST which we encurage members to attend if they are having concerns with accuracy to make sure they are following all the instructions correctly. You need to complete the entire training program to receive a certificate.
Members should continue to use these POC tests but we encourage members to follow the CDC guidance and algorithm on when to conduct confirmation testing of positive antigen tests. We also would encourage members to conduct confirmation testing with PCR tests in other situations not covered by CDC guidance where asymptomatic residents or staff test positive with the antigen tests given the recent reports of false positives.
- If asymptomatic residents test positive with an POC antigen test, they should be placed into TBC and single room if possible but not moved to a COVID-19 (+) or cohorted with a known positive resident until confirmation testing with PCR is obtained.
Most important, the false positive reports emphasized the need for communication from HHS on how to handle these cases, which will happen even with PCR testing. We understand that members are receiving different directives from their state health departments ranging from being required to report all positive test results, even if they are found to conflict with confirmation testing to being advised not to use the antigen analyzers. We are working aggressively with HHS to get written information out to address what to do in the case of false positives, whether from antigen or PCR tests. This includes recommendations for cohorting and isolation; reporting to the state and to the NHSN; not treating a false positive as an outbreak; implications for Provider Relief Fund performance incentive payments.
Abbott Antigen Test Kits
As you have heard in the media and other reports, HHS has purchased all of the initial Abbot point of care antigen tests and are mailing them to assisted living providers that have a CLIA certificate and to some nursing homes in red zones starting this week. HHS has not published a distribution plan. Abbott will continue to send replacement kits through the end of December. Facilities will not be able to order replacement kits until later this year or early next year as HHS has purchased all the kits they are manufacturing. Abbott has posted training materials on how to use the kits at:
Please note that invoices for these kits were accidently sent to providers. You do NOT need to pay these invoices. Also, information describing the “shipping specifications” that was intended for other large shipments of multiple pallets of test kits was erroneously included and can be ignored. Sadly, you will not be receiving multiple pallets of tests kits.
We learned on September 17 that Abbott BinaxNOW (cards) tests are already in the mail from Abbott. They have reportedly shipped about 1 million of them to SNF operators and 540,000 to assisted living providers with CLIA waivers (there are about 5,400 of them). Home health providers will be on a future distribution list. HHS has not issued a distribution plan in writing.
We received notice this afternoon from the HHS Binax Team that they will offer a webinar tomorrow, September 18, from Noon – 1:00 Eastern, for assisted living facilities receiving Abbott BinaxNOW tests from HHS. Presumably this will help nursing homes as well. The webinar will “walk through the manufacturer’s training, introduce the product, and discuss use in assisted living facilities. During the webinar, Abbott will demonstrate the training tools available and representatives from the U.S. government will be online to speak about the program. Use the following link to register for the training: click here to register .” The webinar will accompany 10,000 registrants. The session will be recorded and available for review and shared. You can also access the Abbott BinaxNOW training portal here.