PCR Tests Give ‘Inaccurate Picture’ of COVID-19 Risk, Says Expert Witness in Manitoba Court Case Against Lockdowns

May 18, 2021 Updated: May 18, 2021

Medical experts who testified before a Manitoba court in a challenge against pandemic restrictions put a spotlight on the limitations of the PCR tests being used to diagnose COVID-19, questioning the legitimacy of their use to justify lockdown measures.

Stanford University professor and epidemiologist Dr. Jay Bhattacharya and infectious disease specialist Dr. Thomas Warren both said the polymerase chain reaction (PCR) test is unreliable for determining whether someone is infectious with the COVID-19 disease.

“The problem with the PCR test is that it can detect the virus even when the virus that was in the original sample actually wasn’t infectious,” Bhattacharya said in an interview. “Even though the virus is present, it might be a viral fragment, there may be lots of reasons, but you have too little of the virus present to pose any risk at all to anybody.”

The doctors are expert medical witnesses for the Justice Centre for Constitutional Freedoms (JCCF) in its Charter challenge against Manitoba’s lockdown measures. The hearings before the Court of Queen’s Bench in Winnipeg began on May 3 and are scheduled to take place over two weeks.

The PCR test is regarded as the gold standard for detecting whether the SARS-CoV-2 virus, which causes COVID-19, is present in a sample such as mucus collected from a person’s nose or throat using a swab.

Dr. Jared Bullard, who heads the Cadham Provincial Laboratory in Winnipeg, testified on behalf of the Manitoba government. Under cross-examination by JCCF lawyers, Bullard said PCR test results don’t verify infectiousness and were never intended to be used to diagnose respiratory illnesses, according to a May 11 JCCF news release.

He added that the PCR test for the SARS-CoV-2 virus could register as positive up to 100 days after exposure—long after the one- to two-week period during which the person would be contagious.

Positive Doesn’t Necessarily Mean Infectious

The PCR test works by amplifying, or doubling, the virus’s genetic material, if any, in the sample over multiple cycles until the virus is detected or the test’s cutoff point is reached, Bhattacharya explained. Different PCR tests may have different cutoff points depending on various factors such as how the test is designed.

The number of cycles it takes for the PCR test to detect the virus is called the cycle threshold (Ct) value. Based on his study of the issue since last spring, Bullard said he found that positive cases detected at higher Ct values represent weaker positive results. “For example, someone with a positive PCR test that is run at 18 cycles is more likely to be sick and infectious than someone who has a test run at a Ct value of 40,” says the JCCF news release, noting that “testing for COVID at higher threshold levels can result in false positives.”

Bullard testified that the most accurate way to determine infectiousness is to try to grow a cell culture from a patient’s sample. He found that, for samples that tested positive at 18 Ct, only 44 percent would grow in a lab, suggesting that 56 percent were non-infectious. He was unable to develop any viable lab cultures for samples that tested positive at Ct values higher than 25, which implies that “positive” cases resulting from those tests were most likely non-infectious.

Manitoba is aware of this inverse correlation between the Ct value and infectiousness but “still does not consider Ct values as a proxy for infectiousness in its public health response to COVID-19,” the JCCF news release said.

A study published last July in the Journal of Clinical Virology showed that Bullard’s Cadham lab was using a positivity cutoff of 36.5 Ct on COVID-19 PCR tests, and that Canadian labs used a Ct value of between 30 and 45 for determining a positive test result.

Moreover, both Bullard and Dr. Brent Roussin, Manitoba’s chief public health officer, confirmed under cross-examination that labs don’t provide Ct values to public health officials. Roussin admitted that he could mandate that Ct values be provided to him but has not done so.

Both doctors declined to comment for this story due to the issue still being before the courts.

In January, a World Health Organization notice urged caution in the use of the tests. “Most PCR assays are indicated as an aid for diagnosis; therefore, health-care providers must consider any result in combination with timing of sampling, specimen type, assay specifics, clinical observations, patient history, confirmed status of any contacts, and epidemiological information,” the notice read.

‘Lockdowns Are Bad for People’s Health’

Dr. Bhattacharya told The Epoch Times that data misinterpretation leads to bad public policy.

“Not accounting for the number of doubling times in the PCR test gives you an inaccurate picture of whether the disease is actually dangerous or not in the community. Very often, a dangerous picture will lead to other actions like putting in curfews or other lockdown actions,” he said.

“Lockdowns are bad for people’s health in many ways. Most of the vulnerable populations have been vaccinated in Canada, so there is no need to continue these lockdowns.”

Florida is one example of jurisdictions that consider Ct values in their public response to COVID, and Bhattacharya wonders why more jurisdictions don’t do the same.

“If we monitored who showed symptoms and took account of viral load and infectivity, we could make more nuanced and effective public health decisions. It would not be much more expensive to do,” he said.

Bhattacharya is one of the three authors of the Great Barrington Declaration, which calls for the use of herd immunity, vaccines, and the protection of the vulnerable in response to the pandemic, rather than relying on lockdowns with their devastating public health effects. A tenured professor, Bhattacharya said many doctors have affirmed his recommendations privately but are reluctant to do so publicly “for fear of losing their jobs.”

“It is unlike anything I have seen in my professional career, and it is disturbing,” he said.

The JCCF’s clients in the Manitoba case include seven churches and three individuals.

Allison Pejovic, the JCCF’s lead counsel on the Manitoba case, told The Epoch Times that the “non-pharmaceutical interventions” made by the province since November are unjustifiable infringements on the Charter rights of freedom of assembly, worship, and expression. The JCCF also alleges discrimination since people were barred from church services, yet are allowed to go to liquor stores and cram into buses, among other activities.

“The majority of people have a 99.77 percent chance of recovering if they get COVID-19,” Pejovic said. “We provided the science to the court. Our applicants are definitely not anti-science. They’re pro-science, and they want their freedoms back.”