Detection of SARS-CoV-2 in nasopharyngeal swab samples from COVID-19 patients in Riyadh, Saudi Arabia: a PCR-based study.

Abstract

This study involved laboratory experiments using conventional PCR to detect the RNA-dependent RNA polymerase protein (RdRp) and Envelope (E) genes in Forty-Seven nasopharyngeal swab samples from COVID-19 patients in Riyadh, Saudi Arabia. Gel electrophoresis results showed amplification of the RdRp gene in 85.1% of the samples and the E gene in 89.4%, confirming the widespread presence of these viral genes. The presence of bands in positive controls indicated the specificity of the primers whilst no bands were detected in the negative controls, indicating the absence of contamination. The study also included data collection from databases to explore the demographic and clinical characteristics of COVID-19 patients. The male to female infection ratio was 363:63, significantly favoring males (P ≤ 0.05). Fever was present in 81.46% of patients (P ≤ 0.05). A significant portion (60.56%) had not contacted positive cases or traveled outside Saudi Arabia (P ≤ 0.05). The Saudi to non-Saudi ratio among patients was 24.65-75.35% (P ≤ 0.05). Age distribution showed 62.21% of patients were under 50 years old (P ≤ 0.05). ICU admission was required for 12.21% of patients (P ≤ 0.05). Co-morbidities were present in 27.46% of patients (P ≤ 0.05). The mortality rate was low, with a deceased to alive ratio of 1:141 (P ≤ 0.05). Gel electrophoresis revealed that 85.1% of samples showed amplification for the RdRp gene, and 89.4% for the E gene, confirming the widespread presence of these viral genes among the samples tested.