(Natural News) For the past months, government agencies such as the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) have been relying on Wuhan coronavirus (COVID-19) testing results to track the spread of the pandemic.
But in recent months, both agencies have begun to concede that the testing methods that they’re using may not be as accurate as they would want them to be. They acknowledge that an increasing number of so-called positive test results are actually false positives.
FDA acknowledges false-positives increase as actual cases go down
On Nov. 3, the FDA released new guidelines for rapid antigen testing for COVID-19 that acknowledged a high likelihood of incorrect results. The guidelines stated that health care professionals “should expect some [false-positive] results to occur.” These would occur even when “very accurate” tests were used to screen large populations with “a low prevalence of infection.”
The FDA stated that the accuracy of rapid tests depends almost totally on the amount of COVID-19 in the population being tested, stating: “As disease prevalence decreases, the percent of test results that are false positives increase.”
As an example, the FDA stated that a test with 98 percent specificity would accurately screen “just over 80% in a population with 10% prevalence.” This would mean that 20 out of 100 positive results would be false positives.
The agency added that in a population with only a one percent prevalence, only 30 percent of those who test positive for the disease would actually have it.
“Health care providers should take the local prevalence into consideration when interpreting diagnostic test results,” the FDA emphasized.
The prevalence rate of COVID-19 has actually been quite low in a number of states. It has been recorded as between zero and 1.79 percent in Idaho and 6.4 percent in Pennsylvania. Meanwhile, the CDC estimated its prevalence in the New Orleans metropolitan area to be at around seven percent.
The FDA also details a number of additional reasons for rapid testing inaccuracies. These included cross-contamination and complications in processing samples in batches. (Related: Coronavirus testing can be manipulated to make vaccines look more effective.) (Continue reading …)