#CtValue is the metric that determines #COVID19 positivity status & relative viral load. We are working on CT values in association with demographic & clinical factors in Pakistani patients. This showcases our work on Ct values. @DrNiazAhmadSI @OfficialNcoc #COVID19inPakistan

Our data shows that Ct values alone may not determine the COVID19 severity in our population. What are CT values? You can find the answer to this question in this thread. https://twitter.com/Nosheen_Z/status/1386656073218772995

Ct values indirectly measure the viral load. Several factors, including; sample collection method, type of RT-PCR kit, could affect these values. Researchers are working on the association between Ct values and COVID19 severity.

Different RT-PCR kits detect different viral genes of the coronavirus. Most of the tests at our collaborating diagnostic labs (Lahore-based) were conducted using a version of the @SANSURE_BIOTECH RT-PCR kit (we will call it Sansure 1).

Different kits detect different viral genes. If you look at thismatrix, it displays the genes targeted by the kits used for this work. The green box shows that the gene labeled on the top was detected by the kit labeled on the right. For instance, Sansure 1 detected Orf1ab & N.

For each gene, the RT-PCR machine may give us a separate Ct value. Clinically it is irrelevant which viral gene is detected. If either of these genes is detected at a Ct value of 35-40 (depends on the kit), the patient is considered COVID19 +ve.

If the Ct value is higher than this, the test is negative. The test is also negative if the Ct value is 0.

We are studying the Ct values for three viral genes, Orf1ab, N, or RdRp genes. We found that age, sex, or comorbidities do not affect the Ct values of either of the gene studied for this work.

This means that the adverse outcomes of COVID19 in older patients or people with comorbidities are not merely determined by the Ct value.

We observed that Ct values for a few viral genes were slightly lower in the patients that developed COVID symptoms. But the difference between the Ct values of symptomatic and asymptomatic patients was not very significant.

We conclude the Ct values may have limitations in reliably predicting the disease severity and should be used or reported with caution.

We are also working on other factors associated with COVID severity in Pakistani patients. This thread showcases our work on the COVID risk factors. https://twitter.com/Nosheen_Z/status/1376923342201106435

For some reason, most of the major Pakistani labs are not sharing their data. We cannot simply rely on the binary (negative/positive) data or wait for the western countries to tell us what to do next. We need to study our own population and trends. #collaborate @OfficialNcoc

We are thankful to our partner labs ( #HormoneLab & #TestZone) that gave us data access and allowed us to collect detailed clinical information from the patients. We are also thankful to the patients that consented to be a part of this study.

We thank all the researchers @MunirRimsha @NailaShoaib14, @NailaRiaz000, @FarhadAlishah17, @Noshaba_16 who worked with @Nosheen_Z
on this project. Also, Prof. @DrNiazAhmadSI for his kind support.