Molecular SARS-CoV-2 surveillance in Bavaria shows no Omicron transmission before the end of November 2021

Infection. 2022 Jun;50(3):761-766. doi: 10.1007/s15010-022-01767-1. Epub 2022 Mar 1.

Abstract

Background: Five SARS-CoV-2 variants are currently considered as variants of concern (VOC). Omicron was declared a VOC at the end of November 2021. Based on different diagnostic methods, the occurrence of Omicron was reported by 52 countries worldwide on December 7 2021. First notified by South Africa with alarming reports on increasing infection rates, this new variant was soon suspected to replace the currently pre-dominating Delta variant leading to further infection waves worldwide.

Methods: Using VOC PCR screening and Next Generation Sequencing (NGS) analysis of selected samples, we investigated the circulation of Omicron in the German federal state Bavaria. For this, we analyzed SARS-CoV-2 surveillance data from our laboratory generated from calendar week (CW) 01 to 49/2021.

Results: So far, we have detected 69 Omicron cases in our laboratory from CW 47-49/2021 using RT-qPCR followed by melting curve analysis. The first 16 cases were analyzed by NGS and all were confirmed as Omicron.

Conclusion: Our data strongly support no circulation of the new Omicron variant before CW 47/2021.

Keywords: COVID-19; Omicron; SARS-CoV-2; Surveillance; Variants of concern.

MeSH terms

  • COVID-19* / diagnosis
  • COVID-19* / epidemiology
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Real-Time Polymerase Chain Reaction
  • SARS-CoV-2* / genetics

Supplementary concepts

  • SARS-CoV-2 variants