Influenza, RSV and COVID-19: final epidemiological review of the season in Luxembourg
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The National Health Directorate (Direction de la santé) has published the last weekly report on the spread of acute respiratory infections in the country this season. Data for the 12th week of 2025 (17 to 23 March) indicate a steady decline in the activity of most viruses, bringing the winter infection season to an official end. The next series of reports will not be published until October.
Compared to the previous week, the number of laboratory-confirmed cases fell 35 per cent from 387 to 253. This is the seventh consecutive week in which a downward trend has been recorded. In the spectrum of viruses detected, influenza B accounts for 57 per cent and influenza A 43 per cent. Among influenza A strains, subtypes A(H3) (58%) and A(H1)pdm9 (42%) predominate.
There are also fewer cases of respiratory syncytial virus (RSV). During the reporting week, 57 cases were recorded, which is 20% less than a week earlier (71). This confirms the seasonal nature of RSV circulation, typical for the winter-spring period.
In contrast to other respiratory viruses, the number of SARS-CoV-2 cases increased slightly from 25 to 28, an increase of 12%. Despite this, the level remains relatively low. Virus concentrations in wastewater also show fluctuations over the last five weeks, with a slight increase at week 12.
According to the latest genomic sequencing results, three JN.1 sub-variants were prevalent in Luxembourg in February: XEC (57.7%), KP.3 (12.9%) and LP.8.1 (12.9%). Their spread has not yet caused a significant increase in infections or hospitalisations, but monitoring is ongoing.
Thus, winter 2024/2025 passed without epidemic outbreaks and, despite periodic fluctuations in the data, the situation with respiratory infections remains stable. The main focus going forward will be on preparing for the next season.
