Key Points

Following a gradual increase in COVID-19 cases in early February, the Île-de-France region experienced rapid community spread in March, with the epidemic peaking in week 13, from March 23 to 29. The impact of the epidemic was significant in Île-de-France. Residents of Île-de-France
accounted for approximately 40% of Covid-19 deaths recorded in France since March 1, whether in hospitals or nursing homes.

The lockdown was followed by a sharp decline in the need for Covid-19 care. First observed in outpatient settings during week 14, from March 30 to April 5, and then in hospitals starting April 7, this trend continued through week 24, from June 8 to 14, five weeks after the lockdown was lifted.
This downward trend reversed in week 26. Between weeks 27 and 32, most regional epidemiological indicators showed an increase in viral circulation in Île-de-France, particularly in Paris.

In week 36 (August 31–September 6), the incidence rate now exceeds 100 new cases per 100,000 inhabitants in the Île-de-France region, compared to 93.3 the previous week. The trend of this indicator appears to be slowing slightly across all departments except Val d’Oise. The alert threshold (50) remains exceeded in all departments of the region. The department of Seine-Saint-Denis has also exceeded the incidence rate of 100 cases per 100,000 inhabitants, joining the departments of Hauts-de-Seine, Val-de-Marne, and Paris. The region accounts for 4 of the 7 departments exceeding this threshold nationwide.

The testing rate stabilized in week 36 in the region below 1,500 tests performed per 100,000 inhabitants, mirroring the trend at the national level. The stagnation in the number of tests performed and the increase in the time required to obtain results suggest that laboratories in the region are reaching capacity. The positivity rate of tests performed is rising slightly. These trends call for caution when interpreting changes in the incidence rate.

The 20–30 age group remains the age group most heavily affected by the spread of the virus. The distribution of positive tests by age group follows the same pattern as in previous weeks. The continued spread of the virus maintains the risk of transmission to older populations and those at risk of severe complications.

The previous week, 45 clusters were under investigation; this number rose to 56 in week 36. Nearly two-thirds of these clusters involve workplaces, social housing and rehabilitation facilities, and healthcare facilities. With the start of the school and university year, the proportion of clusters in school settings reached 5.2%.

Indicators from community healthcare surveillance networks continue the upward trend that began in week 34. Hospital-based indicators are also rising: the 24% increase in hospitalization rates is accompanied by a moderate rise in intensive care admissions.

The start of the school year, the continued rise in biological indicators, and the beginning of an increase in signals from healthcare facilities warrant maintaining public health efforts and vigilance at an elevated level for the coming weeks.