Stephen Schumacher & Dr. Thomas Locke: Point, Counterpoint on COVID Testing, False Positives and Dissent
Several months ago Stephen Schumacher wrote to Dr. Thomas Locke, Jefferson County’s Health Officer, regarding questions and concerns he had about protocols being used in tests for COVID-19. He did not receive a response. After Port Townsend Free Press published several of his articles, (on masks, on how Jefferson County may still have no deaths from COVID, and a ticker-tape of news on resistance to COVID lockdowns and questions about vaccines) as well as an article by Annette Huencke based on information obtained from a public records request to Jefferson Healthcare that raised questions about the validity of COVID test results, he has now received a response. Both gentlemen copied Port Townsend Free Press in their correspondence, that also went to County Commissioners and other public officials.
Mr. Schumacher initiated the exchange with the following correspondence to the Jefferson County Board of County Commissioners:
February 1, 2021
Dear Jefferson County Commissioners,
Watching the Zoom of this morning’s BoCC meeting, I noted that Dr.
Locke did not answer or even address any of my questions at bottom,
so they are all still on the table. I’m mystified by his
mischaracterization of well-documented concerns over 90% false
positive rates at high cycle counts as “nitpicky” and his
easily-refuted opinion that PCR tests are “highly accurate”.
Philip Morley observed that Jefferson Healthcare handles only a small
percentage of our county’s PCR testing, with most conducted by UW and
others. If so, that raises the additional question:
7) What Cycle Threshold is used by each organization performing PCR
testing in our county, and approximately what percentage of testing
is done by each organization?
Because of the critical importance of the cycle count in evaluating
the significance of a positive PCR test result, both pieces of
information need to be reported to individuals as well as in overall
county statistics.
Dr. Locke’s report began by warning about a tripling of cases with 26
new ones last week if I heard correctly. But what are the cycle
counts of these new cases? It makes a huge difference whether they
were found positive after 20 amplification cycles or after 45 cycles.
My interest is getting at the truth, not politics. But today’s
meeting seemed concerned about county cases showing percentage
improvements before a Feb. 14 deadline One way to achieve that in a
hurry might be to re-examine recent cases and reclassify any that
were incorrectly counted due to amplification cycles higher than 33,
then continue using that rule for new cases. Not only would that be
the right thing to do, it might achieve the “negative cases” Greg
ruefully joked are needed!
Yours truly,
Stephen Schumacher
— Pubic Comment sent 8:28 PM 1/31/2021 —
Dear Jefferson County Commissioners,
On September 2, 2020, I sent the following Public Comment to the
Jefferson County Board of Health and Health Officer Dr. Tom Locke:
“Per the August 29 New York Times report [of 90% false positives at
40-cycle threshold], I’m concerned about the criteria used to
determine confirmed cases of COVID-19 in Jefferson County. Do all
these cases exhibit symptoms, or are “cases” being equated to
positive test results? If the latter, what percentage of cases
exhibit symptoms? Are positive test results being recorded using PCR
tests, and if so, what is the Cycle Threshold value used for these tests?”
I never received any answers to these questions nor have seen them
addressed by Dr. Locke in the press.
Last week the Port Townsend Free Press reported that Jefferson
Healthcare is “using a PCR assay with a 45-cycle threshold, well
beyond the outer limits of reliability.”
https://www.porttownsendfreepr
This revelation raises various accountability issues, including:
1) Why did our county have to wait nearly 4 months to learn about its
45-cycle threshold from a fortuitous Public Records Request?
2) Since Dr. Locke was also Clallam Health Officer until recently, is
this same unreliable 45 Ct test also in use throughout Clallam County?
3) Was the choice to use this 45 Ct test ever discussed and approved
by the Jefferson County Board of Health or County Commissioners? If
not, was it ever even reported and its significance explained to them?
4) Does Dr. Locke or anybody else keep statistical track of
cumulative cycle counts for positive tests and resulting cases in our
county, or is this info unavailable or being ignored? Could this
information be regularly published in the media, or at least be made
available upon request?
5) Does our county always order a second test following a positive
PCR result, and if not, how often and on what basis? Are all
positive tests treated as COVID-19 cases regardless of symptoms, and
if not, how often has high cycle count been used to discard extremely
weak positive test results?
6) How many county residents have been reported as cases,
quarantined, and contact-traced based on cycle counts above 33, when
the CDC shows “it is extremely difficult to detect any live virus in
a sample above a threshold of 33 cycles”?
/s/ Stephen Schumacher
Today Dr. Locke responded:
Mr. Schumacher,
Cycle threshold values on PCR tests performed to detect SARS-CoV-2 are not routinely reported by laboratories to health departments or the person ordering the test. The Washington State Department of Health establishes standards for what is considered a positive PCR test and is reportable as a notifiable condition. The local health officer has nothing to do with establishing CT parameters or any other diagnostic lab parameter. If you have an issue with CT values you should take it up with Washington DOH or the FDA. Jefferson County Public Health does case investigations and contact tracing of all positive tests reported to Washington State and available to us through a confidential on-line registry known as WEDSS.
The fact that a thermal cycler can perform up to 45 amplification cycles does not mean that ALL tests are amplified to that degree. Samples are cycled until a signal is detected or they have undergone the maximum amplification of the testing protocol. Samples can have high CT values for many reasons — poor sample quality, degradation of the sample during transport, low viral levels in the person being tested, and testing late in illness when fragments of non-replicating virus can be detected. And it is certainly true that high CT values correlate with lower transmission risk (assuming adequate sample collection and specimen transport). Setting standards for FDA approved diagnostic tests is a federal regulatory function. States set standards for notifiable conditions such as SARS-CoV-2 infection. County health officers, local boards of health, county boards of commissioners, and public hospital district commissioners have nothing to do with these decisions.
Again, if you have grave concerns that the Washington State Department of Health is using scientifically indefensible criteria for determining which COVID-19 PCR tests are positive, please share your expertise and concerns with them. These criteria are not set by county health officers or local hospital districts. Nor do we manufacture or license the PCR machines that are used to test diagnostic specimens for SARS-CoV-2. We rely on these tools along with our case investigations (looking at exposure risk, symptom onset, and other risk factors) in assessing cases. False positive tests can occur with any diagnostic technology. They appear to be quite infrequent with PCR testing, especially when a person has a COVID-like illness or a recent exposure to a confirmed case. If your goal is to support the pandemic denialism that Ms. Huenke promotes in the “Port Townsend Free Press” article you reference, I could not disagree more. With the spread of more transmissible variants of SARS-CoV-2, the social cost of pandemic denialism is increasing. If sizeable numbers of people indulge in the wishful thinking that attempts to control COVID-19 transmission are unnecessary, it is only a matter of time before variant strains become predominant. We still have time to avert this future or at least slow it enough to allow widespread vaccine deployment. I urge you to join the community fight against COVID-19 and stop attacking those who are working long hours trying to protect their community from the worst public health emergency in the last 100 years.
Sincerely,
Thomas Locke, MD, MPH
Jefferson County Health Officer