Last update
Week 3 review: 15 - 21 January 2024
The weekly retrospective gives a summary of trends in acute respiratory infections, including COVID-19, influenza (influenza virus) and respiratory syncytial virus (RSV).
Trends of the week
COVID-19: Decrease in the number of cases and the positivity rate of COVID-19.
Respiratory syncytial virus (RSV): Decrease in the number of RSV cases.
Influenza: increase in the number of influenza cases.
COVID-19 / SARS-CoV-2
From 15 to 21 January 2024 (week 3), the number of people testing positive for SARS-CoV-2 dropped to 150 cases, compared to 196 cases the previous week (-23%).
The positivity rate fell to 7% compared to 10% the previous week. The viral concentration detected in wastewater is decreasing [1].
These indicators suggest that the circulation of SARS-CoV-2 has decreased.
The latest sequencing data available for weeks 52/2023-02/2024 show a preponderance of the JN.1 variant (85.1%) (95% CI 78.3-91.8%) followed by the BA.2.86 variant (11.2%) (95% CI: 5.9-18.8%). [2]. It should be noted that the JN.1 variant is a descendant of the BA.2.86 variant with an additional mutation on its spike protein.
Influenza
For the week of 15 to 21 January 2024 (week 3), the number of influenza cases reported by laboratories increased to 703 cases compared to 441 cases in the previous week, presenting 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 the week of 15 to 21 January 2024 (week 3), the number of respiratory syncytial virus (RSV)-positive individuals reported by laboratories dropped to 15 cases, compared with 29 the previous week, presenting an decrease of 48%. The peak of the epidemic this season was reached in week 50, from 11 to 17 December 2023.
Press release by the Ministry of Health and Social Security