Credit: MSAN
On Thursday 4 December 2025, the Health Directorate of Luxembourg's Ministry of Health and Social Security published its weekly overview on the evolution of major acute respiratory infections, including COVID-19, influenza (flu) and respiratory syncytial virus (RSV) for the week of Monday 24 to Sunday 30 November 2025 (week 48).
Decrease in COVID-19 / SARS-CoV-2 cases
During week 48, the number of positive COVID-19 cases decreased from 66 to 51, a drop of 23% compared to the previous week. On the other hand, the viral concentration detected in wastewater increased slightly. The latest available sequencing data reveal that the XFG variant (54.2%) and its sub-variant XFG.3 (29.1%) were predominant.
Increase in flu cases
The number of flu cases reported by laboratories increased from 79 to 173, up by 119% compared to the previous week. Influenza A accounted for 98% of the typed results while influenza B represented 2%.
Slight increase in RSV cases
A slight increase of 4% was observed for RSV, with 93 confirmed cases, compared to 89 the previous week. Since October 2025, 75% of infections have been in children under nine years old, indicating that the virus primarily affects younger people.
