Key Points

COVID-19

Epidemic pressure indicators point to a sharp increase in viral circulation that is becoming entrenched across Réunion.

Hospital indicators were at a high level, with a sharp increase in the number of new hospitalizations and new admissions to intensive care. This intensification of the impact on hospitals must be monitored closely given the reduced staffing levels during this end-of-year period. The unvaccinated are the most affected by these severe cases.

The Delta variant remains the dominant strain on the island. However, an increasing number of Omicron variant cases are being sequenced; while imported cases are mostly identified, it is important to note that the number of locally transmitted cases is also on the rise. It is certain that the Omicron variant is already circulating on the island; even though the increase in new confirmed Omicron cases is not very significant, a further surge in viral circulation linked to this variant is possible in the coming weeks.

Thus, the Omicron variant, whose higher transmissibility has now been demonstrated, calls for the utmost vigilance, particularly in the context of gatherings during the holiday season. It is essential to combine efforts to continue vaccination measures (flu and COVID-19) with strict adherence to preventive measures.

Bronchiolitis

There has been an increase in emergency room visits and hospitalizations due to bronchiolitis among children under 2 years of age compared to the previous week. The proportion of cases is also rising, as 2 out of 10 total emergency room admissions were for bronchiolitis, compared to 1 out of 10 the previous week. With the rise in bronchiolitis surveillance indicators, Réunion has returned to the pre-epidemic phase.

Influenza

The number of emergency department visits for influenza-like illness (ILI) rose sharply in Week 51 (43 cases vs. 28 in Week 50, a 53% increase), primarily involving children under 15 years of age (84% of all ILI visits). Four hospitalizations were reported in Week 51 versus none in Week 50, all involving children under 15 years of age. One severe case was admitted to pediatric intensive care in Week 51. In primary care, the number of consultations for acute respiratory failure has remained at a high level for the past 5 weeks (101 in Week 51 vs. 120 in Week 50), indicating community circulation of respiratory viruses. Virological surveillance conducted by the sentinel physician network has identified 5 positive cases of influenza subtype A(H3N2) since early December. According to hospital virological surveillance, 42 positive influenza samples have been identified since early December (versus 32 in November), all of subtype A(H3N2). Against the backdrop of an intensifying COVID-19 epidemic and with rising indicators of flu-like illness coupled with the onset of a public health impact marked by an increase in hospitalizations, Réunion is now experiencing a flu epidemic.