Situation in Rhône-Alpes: the outbreak is subsiding

The epidemic threshold for influenza was crossed during Week 5 (January 30 to February 5), and the incidence rate peaked during Week 7 (February 13 to 19). The incidence rate, which has been declining since Week 8 (February 20–26), remains above the epidemic threshold. Since November 1, 2011, when surveillance of severe influenza cases began, 74 people have been admitted to intensive care in Rhône-Alpes. These are mainly people aged 65 and older. One-quarter of the patients had been vaccinated against influenza, and 50% developed acute respiratory distress syndrome (ARDS). The weekly number of hospitalizations for severe influenza cases in intensive care has been decreasing since Week 9 (February 27–March 4), but the data for Weeks 10 and 11 are still provisional.The proportion of emergency department visits by patients aged 75 and older has continued to decline over the past two weeks. Furthermore, the number of clustered cases of Acute Respiratory Infection in nursing homes peaked in week 8 and has been decreasing since week 9. The majority of outbreaks for which etiological testing was performed are linked to influenza.The samples collected have primarily detected the A(H3N2) virus, both in samples taken by GROG physicians and in those taken by hospitals.