Key Points

The 2018–2019 winter season was marked by an 8-week influenza epidemic that had a significant impact on hospitals and was characterized by the co-circulation of the A(H1N1)pdm09 and A(H3N2) viruses, with very few B viruses detected.
The epidemic resulted in excess mortality from all causes of approximately 8,100 deaths in mainland France (813 in the region). The region was one of the least affected in terms of excess mortality. However, the case fatality rate for severe influenza cases was higher than the national average (17% versus 14%). During this epidemic period, 216 influenza cases were hospitalized in the region’s intensive care units, with half of the units participating in this surveillance.
The severity of the 2018–2019 winter epidemic is also illustrated by the high number of reports of clusters of acute respiratory infections (ARI) in long-term care facilities (LTCFs), though these were as numerous as in the previous winter (154 vs. 159 the previous season). Vaccination
coverage among individuals targeted for influenza vaccination remains low, with approximately 51% of people aged 65 and older vaccinated during the 2018–2019 season in Nouvelle-Aquitaine.

The 2018–2019 winter season was also marked by a bronchiolitis epidemic of greater magnitude than the two previous seasons, with a more intense epidemic peak. The outbreak lasted 11 weeks, a duration comparable to previous seasons (except for 2017–2018, which lasted only 7 weeks). The proportion of hospitalizations for bronchiolitis following a visit to the emergency department was, however, slightly lower than in the previous season.

The acute gastroenteritis outbreak during the winter of 2018–2019 was prolonged. Activity remained sustained from early November through late April, peaking in week 2 in outpatient care and in week 14 in emergency departments, corresponding to the peak of activity among children under 5 years of age. Overall, the acute gastroenteritis (AGE) outbreak during the 2018–2019 winter began earlier and was less severe than the previous winter, except among children under 5 years of age.

Surveillance of winter illnesses for the 2019-2020 season will remain unchanged from the previous season.