Epidemiological description and analysis of RdRp, E and N genes dynamic by RT-PCR of SARS-CoV-2 in Moroccan population: Experience of the National Reference Laboratory (LNR)-UM6SS

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a new infectious disease that first emerged in Hubei province, China, in December 2019. On 2 March 2020, the Moroccan Ministry of Health confirmed the first COVID-19 case in Morocco. The new virus SARS-CoV-2 was identified in the sample of a Moroccan expatriate residing in Italy. Without a therapeutic vaccine or specific antiviral drugs, early detection and isolation become essential against novel Coronavirus.

This study aims to analyze the epidemiological profile of the SARS-CoV-2 in Moroccan cases and to investigate the dynamic of RdRp, N, and E genes in patients from diagnosis until the recovery.

Among 859 COVID-19 RT-PCR tests realized for 376 patients, 187 cases had positive results COVID-19. 4% were positive with the 3 genes RdRp, N, and E, 40 % with N and E genes, 3% with RdRp and N genes, 31% with only the RdRp gene and 22% cases are positives with N gene. The analysis of the Covid-19 genes (RdRp, N, and E) dynamic reveal that more than 6% stay positive with detection of the N and E gene, and 14% with the N gene after 12 days of treatment.

The median period from positive to the first negative Covid-19 RT-PCR tests was 6.8±2.24 days for 44% cases, 14.31± 2.4 days for 30%, and 22.67 ± 1.21 days for 4%.

This a first description of the Moroccan COVID-19 cases and the analysis of the dynamic of the RdRp, N, and E genes. The analysis of our population can help to improve in the care of patients.