antibody testing update:
- now seeing some asymptomatic infections in general pop
- don't have enough high quality day to conclude anything
- <60% of tests distributed are reporting
- there is clear bias in the data
- there are sensitivity issues with test kits
(details follow)
- now seeing some asymptomatic infections in general pop
- don't have enough high quality day to conclude anything
- <60% of tests distributed are reporting
- there is clear bias in the data
- there are sensitivity issues with test kits
(details follow)
data:
- 437 reported results
- 11 positive, 401 neg, 24 inconclusive (user error)
- of positive:
-- 4 out of state (ppl shipped test to sick friends)
-- 3 known cases (broke protocol)
-- 2/392 in SF, 2/40 on peninsula
-- 100% of positives reported SOME symptoms vs 71% of negs
- 437 reported results
- 11 positive, 401 neg, 24 inconclusive (user error)
- of positive:
-- 4 out of state (ppl shipped test to sick friends)
-- 3 known cases (broke protocol)
-- 2/392 in SF, 2/40 on peninsula
-- 100% of positives reported SOME symptoms vs 71% of negs
we traced positives we report here to verify. i think tests underrepresent true positives based on performance w c19 PCR+ patient sera. however 0.5% of SF population (our limited data shows) is 10x reported rate. but i dont have faith in our data given bias, cleanliness, & scale.
anecdotes emerged that indicate there is a very real mild/asymptomatic pop out there..frequent traveler, thought he had bad cold last mo; spring breaker back from cabo, feels ok; young worker, tired. i dont think we can draw any conclusions given bias and size of data set
distribution and bias:
- we give 20 tests to "sourcer" who finds friends/neighbors to volunteer + self-report
- volunteers may be biased to those thinking they have/had c19
- sourcers sending tests out of area & to known c19+ patients (violate protocol)
- <60% tests report back
- we give 20 tests to "sourcer" who finds friends/neighbors to volunteer + self-report
- volunteers may be biased to those thinking they have/had c19
- sourcers sending tests out of area & to known c19+ patients (violate protocol)
- <60% tests report back
sensitivity of tests:
- we have found 6 c19 PCR+ patients for verifying wandfo and raybiotech test kits
- 5 positive with raybiotech (mix of IgG/IgM)
- 2 positive with wandfo
- cross-testing indicates better sensitivity with raybiotech
(cont)
- we have found 6 c19 PCR+ patients for verifying wandfo and raybiotech test kits
- 5 positive with raybiotech (mix of IgG/IgM)
- 2 positive with wandfo
- cross-testing indicates better sensitivity with raybiotech
(cont)
- a local research team is going to run 500 tests from each antibody test manufacturer with actual c19+ patient sera to quantify specificity, sensitivity, and cross-reactivity. they expect to pre-publish in ~2 weeks
- we are donating 500 of our wandfo kits to them for this effort
- we are donating 500 of our wandfo kits to them for this effort
next steps:
- i dont want to distribute more test kits until we see test kit performance analysis data
- we will keep ordering/sourcing to scale up program when ready
- we are also working on a protocol to track test reporting
- i dont want to distribute more test kits until we see test kit performance analysis data
- we will keep ordering/sourcing to scale up program when ready
- we are also working on a protocol to track test reporting
fortunately, it seems these kits are getting FDA approved and coming to market en masse now, i hope this enables other more organized teams to run these analyses in their communities and get mild/asymptomatic population rates estimated quickly and reliably. we will keep going
