Key Points

COVID-19

The COVID-19 epidemiological situation continues to deteriorate at the regional level. Brittany is currently more severely affected than other regions, and several factors can be cited to explain this situation:

• Brittany is a region that has been relatively spared until now and therefore has a larger pool of people susceptible to infection. Even though the region has the highest vaccination rate, the vaccines’ effectiveness is limited against mild cases. This is supported by a low impact on general hospital admissions and no impact on intensive care units.

• A high number of cases at the time certain restrictions on preventive measures were lifted led to an increase in contacts. In the presence of a more contagious variant, this therefore created a snowball effect.

• This high number of cases at the start of this wave can be explained by the fact that Brittany’s trajectory was time-shifted compared to other regions. It had therefore not yet “come down” from the fifth wave.

• This is particularly true in Finistère, as the eastern part of the region has been less spared so far.

Bronchiolitis

• Non-epidemic activity.

• Oscour®: low activity with 40 emergency room visits in S11 (compared to 37 in S10). Bronchiolitis accounts for 4.4% of diagnoses made in emergency rooms among children under 2 years of age, and one-third of these visits resulted in hospitalization.

• SOS Médecins: The number of SOS Médecins consultations for bronchiolitis has stabilized at a low level (n=5 consultations in S11). Bronchiolitis accounts for 3.2% of diagnoses in children under 2 years of age.

• Virology data: sporadic detection of RSV in S11 according to data from the virology laboratories at the Brest University Hospital (2/569) and the Rennes University Hospital (1/310).

Gastroenteritis

• High activity. Very high activity among children in hospital emergency departments.

• Oscour®: decrease in the number of emergency department visits for gastroenteritis in Week 11 compared to Week 10 (n = 306, or -14.0%), across all age groups. This decline affects children under 5 years of age, who account for 68% of cases. In Week 11, gastroenteritis was the third most common condition among children under 5, behind trauma and isolated fevers; gastroenteritis accounted for 11.1% of visits among children under 5 (compared to 1.8% across all age groups).

• SOS Médecins: Decline in the number of SOS Médecins consultations for gastroenteritis, with 156 consultations for this diagnosis in Week 11 (compared to 197 in Week 10, a decrease of 20.8% across all age groups). Across all age groups, gastroenteritis accounts for 6.0% of total SOS Médecins activity and 7.2% among children under 5.

• Sentinelles Network: low activity in week 11: incidence rate of acute diarrhea cases seen in general practice consultations estimated at 68 cases per 100,000 inhabitants (95% CI [34; 102], unconsolidated Sentinelles data).

• Virology data: according to data from the Virology Laboratory at Brest University Hospital, viral circulation of Rotavirus (positivity rate = 24% (5/21)), Adenovirus (1/22), and Norovirus (2/16). According to data from the Virology Laboratory at the Rennes University Hospital, viral circulation of rotavirus (positivity rate = 27%, 9/33), adenovirus (1/33), norovirus (1/33), and sapovirus (1/33); no positive samples for astrovirus.

Influenza and influenza-like illness

• Epidemic activity, rising phase.

• The first available data on the effectiveness of the influenza vaccine show an estimated 50% efficacy against all influenza viruses, across all age groups (unconsolidated data, National Influenza Bulletin).

• Oscour®: continued increase in the number of emergency room visits in Week 11 (n = 234, a 34.5% increase compared to the previous week), across all age groups. This increase affects all age groups, with the exception of those aged 65 and older. 11.5% of these visits resulted in hospitalization.

• SOS Médecins: further increase in the number of SOS Médecins consultations for influenza in Week 11 (n = 412, a 24.1% increase compared to the previous week), across all age groups. This increase affects all age groups except those aged 65 and older. This condition accounts for 15.8% of diagnoses coded by SOS Médecins (all ages), compared to 12.1% in Week 10.

• Severe influenza in intensive care: since November 2021, 8 cases of influenza have been admitted to intensive care (7 type A, including 1 A(H3N2), 1 untyped).

• Sentinelles Network: incidence rate of acute respiratory infection (ARI) cases seen in general practice consultations estimated at 338 cases per 100,000 inhabitants (95% CI [253; 423], unconsolidated Sentinelles data).

• Virology data: According to data from the Virology Laboratory at Brest University Hospital, there has been an increase in the number of positive influenza A samples (positivity rate = 2.8%, 62/2,206). According to data from the Virology Laboratory in Rennes, there has been an intensification of influenza A virus circulation (positivity rate = 40.6%, 126/310). Influenza B virus has not been detected in samples analyzed by these two laboratories since the start of the season