Caractérisation d’un cluster des cas de COVID-19 liés au variant Omicron, en Mauritanie

Objective: To describe the epidemiological and genomic profile of COVID-19 during the 4(th) epidemic wave in Mauritania. Methods: This is a cross-sectional study in Mauritania, from October 1, 2021 to February 28, 2022. Were included all people in the process of travel, performing an RT-PCR, at the level of the National Research Institute in Public Health and patients who have been sampled for sequencing by teams from the Department of Strategic Information and Epidemiological Surveillance. Results: Out of 37,574 RT-PCR tests collected on March 3, 2022, during the study period, 1,465 cases were diagnosed positive for COVID-19 (3.9%), with an average age of 39±14,6 years and a sex ratio of 2.08. Of the 112 genomic sequences performed, 75 were of the Omicron variant (66.9%). The average age was 40±15 years, with extremes of 15 to 82 years and a sex ratio of 0.97. The vaccination status was assured in 67.7% of patients and the peak of the Omicron variant was reached during the first week of January 2022 Conclusion: The Omicron variant was predominant during the 4(th) wave in Mauritania. As part of its response plan against COVID-19, the installation of new sequencing units inside the country and the strengthening of the training of technicians in the virology laboratory will be essential.