Key Points

COVID-19

In the Hauts-de-France region, from February 22 to 28, 2021 (Week 8), 20,368 new cases of SARS-CoV-2 infection were diagnosed (compared to 18,186 cases during the period of February 15–21), representing an estimated regional incidence rate (IR) of 342 cases per 100,000 inhabitants. In week 8, the epidemiological situation continued to deteriorate (+12%) compared to week 7. The positivity rate (9.3%) is also rising and well above the 5% alert threshold, despite a stabilization in the testing rate. The circulation of SARS-CoV-2 in the region continues to intensify and spread geographically, leading to a significant and ongoing increase in the circulation of variants that are more transmissible and under enhanced surveillance, notably the V1 variant identified last week in two-thirds of the screened positive PCR tests. The epidemic’s spread affects all age groups, particularly the working-age population (20–59 years), among whom a rise in the positivity rate is observed, but also affects the most vulnerable (65 years and older), particularly in the Pas-de-Calais department. In mainland France, the epidemic spread was strongest in the Hauts-de-France region during weeks 7 and 8, with a reproduction number significantly above 1 (R-eff Sidep: 1.15 [1.13–1.16]).

Bronchiolitis

In week S08-2021, bronchiolitis activity was on the rise for the second consecutive week at SOS Médecins. Having been on the rise for several weeks in emergency departments, it continued to increase in week S08-2021, though levels remained moderate for both sources. The number of RSV isolates in patients hospitalized at the Lille and Amiens university hospitals was decreasing, while the circulation of other respiratory viruses (rhinovirus and enterovirus) remained stable. Activity in the two Bronchiolitis Networks over the weekend of February 27–28 was slightly higher, at moderate levels. Thus, after a delay of more than 14 weeks in the onset of the epidemic—due in part to the strengthening of and adherence to the preventive measures currently in effect in the context of the COVID-19 pandemic—a clear increase in bronchiolitis activity has been observed since week S06-2021. This trend is expected to intensify in the coming weeks, and the region is currently in the pre-epidemic phase.

Influenza

Since the resumption of influenza surveillance, no influenza activity has been observed in calls to SOS Médecins or visits to emergency departments. The incidence of influenza-like illness estimated by the Sentinelles network has been stable in recent weeks, at a low level. No influenza virus has been isolated so far in patients hospitalized at the University Hospitals of Lille and Amiens.

Gastroenteritis

In recent weeks, SOS Médecins activity for acute gastroenteritis (GEA) has been stable among children under 5 and all age groups, at a moderate level. However, it has been increasing in recent weeks in emergency departments across all age groups and has remained stable among children under 5 at levels that are still low, currently lower than those observed in previous years. This is likely due to the strengthening of hygiene measures in the context of the COVID-19 pandemic. The incidence of acute diarrhea estimated by the Sentinelles network was increasing in week S07-2021. A single enterovirus was isolated in patients hospitalized at the Amiens University Hospital in week S08-2021; none were isolated at the Lille University Hospital.