On Friday 31 December 2021, Luxembourg's national laboratory (Laboratoire National de Santé, LNS) confirmed 50 new cases of the SARS-CoV-2 variant of concern (VOC) Omicron in Luxembourg sampled in the week 20 to 26 December 2021 (week 50).
Due to the emergence of the new Omicron variant, as well as the high incidence rates in the European context, LNS is carrying out targeted PCR tests for potential Omicron cases within 24h from reception of samples. The targeted PCR tests specifically look at the 69/70del, K417N and N501Y mutations, which are hallmarks for Omicron. Once identified, these cases are then prioritised for confirmation by sequencing (at the LNS).
(Note: it is not possible to determine the variant from a positive PCR test (or even a positive antigen test). What happens with positive tests is that the samples are then sent to the LNS for detailed analysis from which they can then determine the variant and other genomic information: this additional process takes a couple of weeks, therefore the delay in reporting variants, etc.)
A total of 2,727 new cases were registered in Luxembourg in week 50 of which 1,054 samples were screened by targeted PCR.
60 samples were identified as potential Omicron cases following the targeted PCR tests and were prioritised for confirmatory sequencing.
In total, 798 resident samples were sequenced, with 704 variant cases detected, of which 50 (7.1%) were Omicron and the rest (654) were Delta and Delta sub-types.
The previous week, week 49, five (0.7%) Omicron cases were detected; this week's data thus represents a ten-fold increase from the previous week.
In total, 55 confirmed cases of Omicron VOC have been detected in Luxembourg so far.
