They will need to develop and provide indicators to track the spread of COVID-19 at the national, regional, and local levels in order to adapt transmission control measures following the lifting of lockdown restrictions, including: social distancing, preventive measures, mask use, and, in particular, isolation measures for all individuals who are contagious or may be contagious—namely, those with a positive COVID-19 RT-PCR test result and their at-risk contacts.

New indicators to detect new cases as early as possible at the finest geographical level

In this new phase of the fight against the epidemic, the surveillance system continues to adapt to closely track its evolution. It will rely on priority indicators designed to reflect, as early as possible, the emergence of new cases and infections, as well as their temporal and spatial patterns. The ultimate goal is to enable public authorities at the national, regional, and departmental levels to:

• Assess and optimize testing and case detection capacity;

• Adapt transmission control measures upon the lifting of lockdown: isolation, contact tracing, and isolation of contacts as close as possible to the area where these individuals live;

• To forecast the need for hospital care, particularly in intensive care units.

New indicators based on the new SI-DEP information system

A new digital tool, the Screening Information System (SI-DEP), is currently being implemented to collect diagnostic test results (RT-PCR) from field laboratories and identify any new cases as quickly as possible in order to contact the patient and their contacts.

Based on this system, which aims for comprehensive and timely reporting of test results, three indicators will be produced by Santé publique France as part of its national oversight of the epidemiological surveillance system.

• Positivity rate: the number of positive cases relative to the total number of tests performed;

• Number of tests performed relative to the number of residents; this indicator assesses actual diagnostic capacity in a given area;

• Number of positive tests relative to the number of inhabitants, which assesses the incidence of the disease.

Broken down at all territorial levels (national, regional, and departmental), these indicators—based on daily RT-PCR diagnoses—are relevant, valid, reliable, and reproducible for the specific and responsive estimation of the epidemic’s dynamics.

These new indicators will be transmitted daily to the Ministry, made available on Géodes, and published in the weekly epidemiological reports.

Existing and still relevant indicators

The indicators already produced by Santé publique France to monitor the epidemic—in urban areas, hospitals, and medical-social facilities, including nursing homes—remain available. They will continue to be useful as a complement to these new indicators. They are published regularly (national and regional weekly epidemiological reports, Géodes mapping observatory).

Adherence to and compliance with preventive measures are central to the fight against the epidemic

As we emerge from lockdown, the commitment and engagement of individuals and communities are essential to reducing the spread of the virus. That is why it is important to monitor adherence to and compliance with measures and recommendations among the general population. Based on weekly national surveys of the general population, four dimensions will be measured:

• compliance with physical distancing rules;

• compliance with isolation rules in the event of symptoms;

• mask-wearing in public spaces;

• the implementation of the 4 preventive measures.

The results of these surveys will enable us to reinforce prevention messages to the public if necessary.