SARS-CoV-2 direct real-time polymerase chain reaction testing in laboratories with shortage challenges

Alaifan, Taghreed; Altamimi, Asmaa; Obeid, Dalia; Alshehri, Turki; Almatrrouk, Shaihana; Albarrag, Ahmed

Aim: In our study, we propose the use of direct real-time polymerase chain reaction (RT-PCR), this test does not require extraction or a preheating step, which saves a lot of cost, labor, processing time and provides a solution for supply shortage. Materials & methods: We assayed 185 nasopharyngeal samples stored in viral transport media. The indirect method was done with RNA extraction step, and the direct RT-PCR was done without an extraction step, both assays were evaluated on a commercially validated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) kit targeting E gene. Results: Our assay showed a sensitivity of 79%, a specificity of 100% and the agreement between methods was 72%. Conclusion: Overall, this simple direct RT-PCR approach can be utilized as a qualitative diagnostic tool for emergency SARS-CoV-2 surveillance in countries with limited resources and may help laboratories to continue testing and at greater frequency despite supply shortages, although with delay in cycle threshold value in comparison with indirect RT-PCR.