Number of reported cases of RSV, COVID-19 and flu during week 42 of 2025;
Credit: MSAN
On Thursday 23 October 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 Monday 13 to Sunday 19 October 2025 (week 42).
Decrease in COVID-19 / SARS-CoV-2 cases
During week 42, the number of positive COVID-19 cases decreased from 293 to 242, a 17% drop compared to the previous week. However, the viral concentration detected in wastewater increased. The latest available sequencing data reveal that the XFG variant (49.2%) and its subvariant XFG.3 (33.5%) predominated in September 2025.
Slight decrease in flu cases, with numbers remaining low
The number of flu cases reported by laboratories fell slightly, from 22 to seventeen cases, over one week. Influenza A represented 94% of the typed results and 6% were influenza B.
Low number of RSV cases
The number of RSV cases reported by laboratories stabilised at ten, compared to eleven cases the previous week, while remaining at a low level.
EO
