COVID-19 Cases Down by 23%, Flu Cases Up by 59%

Luxembourg's Ministry of Health and Social Security has published a weekly retrospective that provides a summary of the evolution of acute respiratory infections, including COVID-19, influenza and respiratory syncytial virus (RSV) for week 3, from Monday 15 to Sunday 21 January 2024.

The overall trends saw a decrease in the number of COVID-19 cases, a decrease in the number of RSV cases and an increase in the number of flu cases.

COVID-19 / SARS-CoV-2

For week 3, the number of people positive for SARS-CoV-2 decreased to 150 cases compared to 196 cases the previous week, a decrease of 23%.

The positivity rate decreased to 7% compared to 10% the previous week. The viral concentration detected in wastewater also decreased.

These indicators suggest that the circulation of SARS-CoV-2 has declined.

The latest sequencing data available for weeks 52/2023 – 2/2024 showed a preponderance of the JN.1 variant (85.1%) followed by the BA.2.86 variant (11.2%). Note that the JN.1 variant is a descendant of the BA.2.86 variant with an additional mutation on its spike protein.

Influenza 

For week 3, the number of cases of influenza (flu) reported by laboratories increased to 703 cases compared to 441 cases the previous week, an increase of 59%.

These data largely overlap with LNS sentinel surveillance which indicates high circulation of the influenza virus, followed by rhinovirus and SARS-CoV-2.

Respiratory syncytial virus (RSV)

For week 3, the number of people positive for respiratory syncytial virus (RSV) reported by laboratories decreased to 15 cases compared to 29 cases the previous week, a decrease of 48%. The peak of the epidemic this season was reached in week 50 from 11 to 17 December 2023.