Infections in Luxembourg have gone down, but it's too early to relax

The Luxembourg Ministry of Health (Direction de la santé) has published a weekly overview of the prevalence of acute respiratory infections for the week 22 to 28 December 2025.

The incidence of influenza decreased by 15% compared to the previous week: 544 cases were laboratory-confirmed against 640 a week earlier. Almost all typed cases (99.6 per cent) were influenza A virus, while type B was found in only 0.4 per cent. Although the numbers are declining, the Ministry of Health emphasises that the virus is still actively circulating. The decline is explained by school holidays, which corresponds to typical seasonal dynamics.

Vaccination remains important, especially for people over 65 years of age, who are more likely to develop serious complications.

Among all respiratory viruses, RSV showed the most marked decrease: minus 48% over the week. 149 cases were confirmed against 285 earlier. Almost 70% of those who fell ill were children under 10 years of age. Despite the decrease, outbreaks in kindergartens and schools remain a real threat.

Cases of SARS-CoV-2 infection also declined, with 70 cases reported, down 24 per cent from a week earlier. However, the viral load in sewage has increased. This may signal latent spread, with people becoming asymptomatic or not being tested.

Sequencing analysis showed the dominance of three strains: variant XFG (40.6%), its sub-variant XFG.3 (23.9%) and NB.1.8.1 (23.9%). All belong to the current Omicron lineage, but with varying degrees of infectivity and resistance. There is no indication yet that they cause a more severe course of disease, but epidemiologists are closely monitoring their evolution.