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 8 to 14 January 2024 (week 2), the number of people testing positive for SARS-CoV-2 dropped to 196 cases, compared to 240 cases the previous week (-18%).
The positivity rate fell to 10% compared to 14% the previous week.
These indicators suggest that the circulation of SARS-CoV-2 has decreased.
The latest sequencing data available for weeks 50-52 show a preponderance of the JN.1 variant (72.0%) (95% CI: 64.1-79.9%) followed by the BA.2.86 variant (16.8%) (95% CI: 10.3-23.3%) and the XBB.1.9 variant (8.0%) (95% CI: 3.2-12.8%) [1]. 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 8 to 14 January 2024 (week 2), the number of influenza cases reported by laboratories increased to 439 cases compared to 360 cases in the previous week, presenting an increase of 22%.
These data largely overlap with LNS sentinel surveillance, which indicates high circulation of the influenza virus, followed by rhinovirus and SARS-CoV-2.1.
Respiratory syncytial virus (RSV)
For the week of 8 to 14 January 2024 (week 2), the number of respiratory syncytial virus (RSV)-positive individuals reported by laboratories dropped to 29 cases, compared with 52 the previous week, presenting an decrease of 44%. 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