Even If Your SARS-CoV-2 PCR Test Is Positive, You May Not Be “Truly Infected”, Says WHO

Bonus: Select feedback on my Sun op-ed

Mentioning the state of Florida in my Dec 14 Sun newspaper op-ed was one of the triggers for a nasty personal attack from a fellow geographer on Twitter, suggesting that I spread “cherry-picked disinformation” and “contribute to ignorance”, “rather than listening to [the health experts]”. After having my olive branch spurned, I decided to ignore these uninformed and underhanded comments and let others think for themselves. Some community members indeed seem to have a better sense of what a geospatial data analyst can contribute to resolving the corona crisis. In response to a similar kick at the expertise of a “professor in the Department of Geography and Environmental Studies” by a Sun reader, other readers’ answers included that “it’s about data and using it properly” (John Cauchi) and “As for this professor, he is a professor because he has critical thinking skills” (John Smith). My personal favourite is Twitter user Darryl Schomson’s observation that “Geographers have a unique, synthetic view of the world which no other discipline has.” I am very grateful for the overwhelmingly positive response and support; hopefully I will find the time to put together a collage of the most insightful comments.

Due to recent events, I want to talk a little bit more about Florida. I mentioned Florida in the op-ed because they had recently mandated their labs to report PCR test results along with the cycle threshold (Ct) count (for source, see my blog post “Brave New Covidworld?“). This was a consequence of concerns about what Stanford professor of medicine Dr. Jay Bhattacharyan calls “functional false positives” (see the interview referenced in my post “Some Doctors Are Giving John Snow a Bad Name“).

As if it was coordinated with my op-ed, the World Health Organization (WHO) this Monday, 14 December 2020, issued an information notice/medical product alert for laboratories that use PCR tests to detect SARS-CoV-2. According to this document, the WHO is responding to reports of “an elevated risk for false SARS-CoV-2 results“.

Part of World Health Organization’s Dec 14 “Information Notice for IVD Users

Important update as of 23 January 2021: The document has been removed from its original location at https://www.who.int/news/item/14-12-2020-who-information-notice-for-ivd-users on the WHO web site. I updated the above links to a copy dated 15 December 2020 from the Internet archive. On 20 January 2021, the WHO has issued version 2 of the same document, which however focuses on the test results of asymptomatic patients rather than the Ct count. Version 2 is also missing one of the action items and I sent an inquiry to the WHO about the difference and about their document management in general.

I have previously written about concerns with false-positive test results, which originally emerged in June if not earlier, see “The Saga of False-Positive COVID-19 Tests” from September 25. While that first post was about “real” false positives, in the sense of test results that are actually wrong, the WHO’s current concern is with the “functional false positives”, where the test results are misinterpreted in conjunction with the cycle threshold value. I have written about this too, see “The Little Pandemic That Could” from November 28. In essence, a positive test result that was obtained after a high number of replication cycles indicates that only a small amount of virus was found and the person likely is not infectious.

Did you notice that I wrote “infectious“? There have been long debates between certain “top” virologists and their followers on one hand, and critical epidemiologists and informed skeptics on the other, about what constitutes an infection and how it relates to infectiousness. There is also an intriguing fact check by Reuters titled “Inventor of method used to test for COVID-19 didn’t say it can’t be used in virus detection“, which I am planning to deconstruct in a separate post. But now the WHO does not even mention infectiousness in their update? They are concerned that some people who tested positive may not be “truly infected“. In other words, these people are … healthy? This would be a blow to reality deniers, COVID worshippers, and lockdown zealots.

Part of Section 3 in Public Health Ontario’s Sep 17/Nov 5 report “An Overview of Cycle Threshold Values and their Role in SARS-CoV-2 Real-Time PCR Test Interpretation

Consequently, the WHO now recommends that labs “Provide the Ct value in the report to the requesting healthcare provider.” Just like Florida decided 10 days ago (and critics have suggested for months).

In the op-ed, I was going to suggest that Canada’s provinces should also report Ct values. However, in reading Public Health Ontario’s “An Overview of Cycle Threshold Values and their Role in SARS-CoV-2 Real-Time PCR Test Interpretation” (dated September 17 but published November 5), I recognized their claim that Ontario’s lab network is too “complex” for Ct reporting. Therefore, instead of just calling for the Ct values to be reported, I asked: “How much longer will it take our provincial governments to develop an approach to analyze and report these data?” Yet, the WHO simply recommends that Ct values be reported with no further conditions or context. We’ll see what our province(s) will do about that.

There is much more to write in response to feedback on the op-ed, but for now, I will leave you with one more gem, a reply from user @SuperMikhail1 to the Toronto Sun’s Dec 13 tweet about the op-ed. Mikhail says: “That’s not an opinion piece that’s a fact piece.” I hope this post shows that my corona research is based on data and facts from government sources, which I critically analyze and interpret, as is my job as an academic.