Antibody tests used to determine if people have been infected in the past with Covid-19 might be wrong up to half the time, the US Centers for Disease Control and Prevention said in new guidance posted on its website.
Antibody tests for Covid-19 wrong half the time, CDC says - CNN
Well, we're screwed. Antibody testing is useless.
However-
From the CDC-
A key CDC priority is to track COVID-19 infections to determine how much of the U.S. population is infected over time. CDC uses a variety of surveillance systems to track COVID-19 cases based on people who seek medical care. However, these systems can miss infections that occur in people who had mild or asymptomatic illness (i.e., no signs or symptoms) who did not seek medical care or get tested.
By using seroprevalence surveys, CDC can learn about the total number of people that have been infected, including those infections that might have been missed. These surveys also can help estimate how much of the population has not yet been infected, helping public health officials plan for future healthcare needs. These surveys can also track how infections progress through the population over time. This is done by taking “snap shots” of the percentage of people who have antibodies against SARS-CoV-2 (also called the seroprevalence) at different time points.
Coronavirus Disease 2019 (COVID-19)
Weird how the CDC uses antibody testing in extensive research and forecasting. They are stupid.
Unless CNN has intentionally misrepresented the CDC words.
The CDC said-
For example, in a population where the prevalence is 5%, a test with 90% sensitivity and 95% specificity will yield a positive predictive value of 49%. In other words, less than half of those testing positive will truly have antibodies.
Does this antibody test exist? I doubt it. This is what is called an "example". This is often used to make a point on the importance of certain parameters.
My Quest Diagnostics antibody test had 90-100% (?) sensitivity and > 99% specificity. I understand this to give a 1% false positive reading in a state where 13% of the population is believed to be infected (Imperial College). So I might get an actual false positive around 7% of the time. Incredibly useful to me and the CDC, and a far more accurate result can be obtained with a second test using different serology.
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This WS forum has be very therapeutic to me trying to sort out the effects of COVID-19. I appreciate the polite back and forth, and challenging of assertions and data. It seems there are two thought processes on coronavirus and I am obviously on one side, the non-alarmist side. I'd like to believe that I am fact-based, but maybe I have biases that I don't see. At this point, I'm kind of exhausted by it and am going to check out. Stay safe my friends!
Anyway, there must be some sleuthing needed in Colorado.
There always is.
