Key points

Bronchiolitis

• Epidemic slowly declining.

• Bronchiolitis-related activity decreased slightly in S03: to 8.5% (vs. 9.7% in S-1) for emergency department visits; to 2.3% (vs. 2.7%) for SOS Médecins calls. Activity is lower than in the two previous winters.

• The rate of bronchiolitis hospitalizations among all coded hospitalizations is decreasing (19% vs. 21% in S1).

• There is a trend toward stabilization in the circulation of RSV in private laboratories (7.5% in S03 vs. 7.4% in S-1) and a decrease in hospitals (6.4% in S03 vs. 7.2% in S-1).

Influenza

• 7th week of the epidemic.

• The proportion of influenza among all emergency department visits across all age groups continues to decline in Week 3, to 5.2% (vs. 5.6% in Week 1). The rate of influenza-related hospitalizations among all coded hospitalizations is also decreasing (3.7% vs. 5.6% in Week 1).

• However, the number and proportion of flu-related visits among children under 15 continue to rise, with 413 cases and 11.0% of flu cases (vs. 9.4% in Week 1). Against the backdrop of the concurrent circulation of the three influenza viruses A(H1N1)pdm09, A(H3N2), and B/Victoria, the current high level of influenza activity among children could lead to a resurgence in hospital indicators among adults in the coming weeks.

• Activity is increasing in the community: 25.3% (vs. 24.4% in Week 1) among SOS Médecins cases in Week 3; 482 consultations per 100,000 inhabitants for Sentinelles in Week 2 (vs. 254 in Week 1).

• Viral circulation is stable in community laboratories (29.0% in Week 3 vs. 28.1% in Week 1) and decreasing in hospitals (18.1% in Week 3 vs. 20.7% in Week 1).

Covid-19

• The SARS-CoV-2 virus continues to circulate at low levels (see pages 6 and 7), as in other regions. The proportion of cases handled by SOS Médecins and emergency departments for suspected COVID-19 remains low.

• Since week 40-2024, 36 severe cases of COVID-19 (all ages) have been reported by the sentinel intensive care unit network.

Acute Respiratory Infections (ARI)

• Since week 40-2024, 208 clusters of acute respiratory infections (ARI) have been reported.

• The number of new clusters is low between week 42 (mid-October) and week 48 (late November).

• The number of reports has tended to increase since then (data not consolidated in weeks 52 and 53).

• In total, 79 ARI outbreaks were attributed exclusively to COVID-19 and 72 outbreaks were attributed exclusively to influenza, 70% of which occurred between weeks S52 and S02.

• Four episodes were attributed exclusively to RSV.

• Since week 40-2024, 12 episodes of COVID-19/influenza co-infection have been reported (including 3 in S51 and 3 in S01) and 4 episodes of influenza/RSV co-infection since S51. One case of COVID-19/RSV co-infection was reported in S01.