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Beware of 'false' Covid-19 results

A healthcare worker takes a swab sample to test a person for coronavirus disease (COVID-19) in Surabaya, East Java Province, Indonesia.
A healthcare worker takes a swab sample to test a person for coronavirus disease (COVID-19) in Surabaya, East Java Province, Indonesia.
Image: Antara Foto/Didik Suhartono/via Reuters

On June 14, Sowetan, in their editorial titled "Covid shows no sign of fatigue", published a few points which I think call for an urgent response. In the opening line the editorial reads: "With an average 9,000 cases of Covid-19 reported a day, SA is now firmly in the grip of the third wave of infection."

First of all, let's correct the use of the word "cases". A case is when someone gets sick from a disease, and that's completely different from a positive test. For example, 9,000 healthy looking people, with no symptoms of Covid-19, may test positive for Covid, but being healthy with no symptoms they cannot be counted as a case. 

The PCR test, which is being used to test people for Covid-19, runs in cycles otherwise known as CT (Count Threshold), and each cycle is "a quantum leap in amplifying or magnifying the original tiny, tiny piece of material taken from the patient’s swab sample".

You cannot run tests at 35 cycles or higher, the test will give you what is called a "false positive". Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases and the chief medical advisor to the president, appeared on a podcast "This Week Virology" saying the PCR Covid test is useless and misleading when the test is run at “35 cycles or higher".

Fauci, a scientist, further says "If you perform the test at a cycle threshold of 35 or more, the chances of it being accurate are miniscule, you almost never can detect a true positive result from a 37 threshold cycle even 36”.

The Ampath laboratory manager told me that most PCR assays have 40-45 cycles. How many cycles were deployed on the 73 and 32 Covid-19 patients admitted at the Steve Biko Academic and Tembisa hospitals respectively?

In the interests of keeping the citizens well-informed with accurate information, this question should be answered and the labs conducting the Covid-19 tests must report the “cycle threshold” for every test they run. 

Tebogo Brown, Witpoortjie

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