Number of reported cases of RSV, COVID-19 and flu during week 44 of 2025;
Credit: MSAN
On Thursday 27 November 2025, the Health Directorate of Luxembourg's Ministry of Health and Social Security published its weekly overview on the development of major acute respiratory infections, including COVID-19, influenza (flu) and respiratory syncytial virus (RSV), for the week of Wednesday 17 November to Tuesday 23 November 2025 (week 47).
Small increase in COVID-19 / SARS-CoV-2 cases
During week 47, the number of positive COVID-19 cases increased from 65 to 67, a rise of 3% compared to the previous week. The viral concentration detected in wastewater also increased. The latest available sequencing data reveal that the XFG variant (54.2%) and its subvariant XFG.3 (29.1%) predominated in November 2025.
Increase in flu cases, but numbers remain low
The number of flu cases reported by laboratories rose slightly, from 50 to 75 cases, representing an increase of 50%. Of the typed results for the week, 95% were influenza A and 5% influenza B.
Number of RSV cases increases
The number of RSV cases reported by laboratories saw an increase of 30%, with 83 compared to 63 the previous week. Since October 2025, 75% of infections have affected children under seven years old, indicating that the virus mainly impacts the youngest population.
