Week 45 review - 6 to 12 November 2023

The weekly retrospective gives a summary of trends in acute respiratory infections, including COVID-19 and influenza (influenza virus) and respiratory syncytial virus (RSV).

Trends of the week:

COVID-19Increase, after a slight decrease during the school holiday week.

Respiratory syncytial virus (RSV): Increased circulation of the RSV virus.

Influenza: few cases of influenza have been detected, with flu circulation remaining at a relatively low level.


From 6 to 12 November 2023 (week 45), the number of people testing positive for SARS-CoV-2 increased to 294 cases, compared to 195 cases the previous week (+51%).

The positivity rate rose to 24% compared with 23% the previous week. The viral concentration detected in wastewater is increasing[1].

Taken together, the 3 indicators suggest that the circulation of SARS-CoV-2 is increasing and that the decrease observed the previous week was probably linked to the school holidays. The latest sequencing data available show a preponderance of the EG.5.1 variant (38.7%)[2].


For the week of 6 to 12 November 2023 (week 45), the number of influenza cases reported by laboratories rose to 14, compared with 4 case the previous week.

These data largely overlap with sentinel surveillance by the National Health Laboratory (LNS), which indicates increased circulation of RSV, rhinovirus, adenovirus and SARS-CoV-2, but little circulation of influenza viruses. [2].

Respiratory syncytial virus (RSV)

For the week of 6 to 12 November 2023 (week 45), the number of respiratory syncytial virus (RSV)-positive individuals detected by the CHL laboratory rose to 37 cases, compared with 19 the previous week, presenting an increase of 94%.

Press release by the Ministry of Health

[1] www.list.lu

[2] https://lns.lu/publications/

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