Number of reported cases of RSV, COVID-19 and flu in 2025-2026, Week 2; Credit: MSSS

On Thursday 15 January 2026, 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 5 to Sunday 11 January 2026 (week 2).

Increase in COVID-19 / SARS-CoV-2 cases

During week 2, the number of positive COVID-19 cases increased from 62 to 69, representing a 11% increase compared to the previous week. On the other hand, the viral concentration detected in wastewater showed a decrease. The latest available sequencing data reveal that the XFG variant (40.6%), its sub-variant XFG.3 (23.9%) and the NB.1.8.1 variant (23.9%) are predominant.

Flu cases increase

The number of flu cases reported by laboratories rose by 43%, from 641 to 915 cases, over one week. Influenza A accounted for 99.8% of the typed results and influenza B for 0.2%.

The Ministry of Health and Social Security recalled that vaccination remains available and primarily targets people aged 65 and over, who face a higher risk of complications from influenza. The ministry noted that vaccination is the most reliable way to prevent seasonal flu and reduce the risk of related complications.

Slight increase in RSV cases

The number of RSV cases reported by laboratories saw a 3% increase, with 151 confirmed cases compared to 147 the previous week. Since October 2025, 62% of infections have occurred in children under the age of nine, indicating that the virus mainly affects younger age groups.

The ministry reminded the public of preventative measures to help limit the spread of viruses. These include:

• washing hands regularly with soap and water for at least 30 seconds, thoroughly rubbing palms, fingers, the backs of hands and under the nails;
• covering the mouth and nose with a tissue when coughing or sneezing or using the crook of the elbow if no tissue is available;
• disposing of used tissues immediately in a bin and washing hands afterwards;
• avoiding physical contact such as hugs, kisses and handshakes;
• avoiding crowds and gatherings during the epidemic season;
• staying at home when ill to avoid infecting others;
• ventilating rooms regularly, at least three to four times a day for ten minutes.