Are rises in positive cases in France due to more tests?

Reader question: How worried should we be that France reported over 30,000 new cases of Covid-19 last week? Is this not just linked to the fact that more tests are being carried out?

Short answer: Partially.

The Connexion gives daily updates on the Covid-19 situation in France via this article, pinned on our website’s homepage.

One statistic we highlight is the recorded number of new cases in France in the previous 24 hours, using information from the government website Santé Publique France.

The number fluctuates and can jump from around 4,000 cases on one day to up to 20,000 or 30,000 on another due to the fact that data provided immediately after weekends and bank holidays is lower because testing facilities are often closed during these times.

Some French media portray these large jumps as a way to to highlight that the Covid-19 situation is worsening in the country.

It is useful to show this figure as it is taken into consideration when the government assesses whether to increase or relax restrictions.

Several readers have asked, though, if the increase in daily positive cases is actually more related to the number of tests being carried out. As around 80% of Covid-19 cases are asymptomatic, it follows that the more tests being carried out the more cases will be identified.

In Dunkirk, for example, where the number of Covid-19 cases has increased significantly recently, a campaign of mass testing was set up. On the first day (February 18), at least 870 people went to be tested.

As a mass testing strategy could lead to more positive cases being identified, it follows that looking at only the daily number of positive cases does not give an accurate picture of the pandemic in France.

Rate of positive tests - a more accurate statistic

This is why our homepage pinned article also includes the ‘rate of positive tests’ in France - this is the percentage of people who test positive out of all the tests being carried out.

It means that even if more tests are being carried out, this figure will not necessarily be affected and thus gives a more accurate reading of the Covid-19 situation.

Our interactive graph below shows the evolution of the rate of positive cases in France.

A Flourish chart

The yellow bars are the total number of tests being carried out. The blue line shows the rate (in percentage) of positive tests.

As the graph shows, this number fell sharply during the second national lockdown in place between October to mid-December 2020. On December 24, it reached a low of just 2.6%.

That figure has steadily risen again. This graph, based on the latest government data, goes until February 26, 2021, when the rate of positive tests was 6.2%.

Today (March 2), the rate is even higher, at 7.3%.

This is still a long way from when the rate of positive tests peaked on October 27 at 16.4%. However, this number has been steadily increasing for the past few weeks which suggests that the Covid-19 situation in France is worsening.

Pressure on hospitals and intensive care units

When lockdown was first introduced in France in March 2020, the key goal was to prevent hospitals and care wards being overwhelmed and this remains a main objective in controlling the pandemic today.

To assess this, we can look at the number of hospitalisations in France and the pressure on intensive care wards.

The chart below shows that there are just over 25,000 people around France currently in hospital due to Covid-19. This is a 2% decrease from last week.

While this number is significantly below the peak number of hospitalisations in France, it is still high compared to in the summer of 2020.

The map below shows the evolution of hospitalisations and Covid-19 cases in France by department, with the number averaged over the past week.

The top left square represents a situation where the number of positive cases is decreasing but the number of hospital admissions due to Covid-19 is increasing.

The bottom left square represents a situation where the number of positive cases is decreasing and the number of hospital admissions is decreasing.

The top right square represents a situation where the number of Covid-19 cases is increasing and the number of hospital admissions due to Covid-19 is increasing.

The bottom right square represents a situation where the number of Covid-19 cases is increasing but the number of hospital admissions due to Covid-19 is decreasing.

Another important figure is the pressure on intensive care wards.

Currently, in intensive care units, 68.8% of the beds are occupied. However, this is based on the number of intensive care unit beds in France at the end of 2018.

France’s regional health agency, the Agences Régionales de Santé, told the newspaper La Montagne that the number of beds has since increased by 24%. This makes a total of 6,733 beds.

The agency noted, though, that these new beds were temporary and were not actually located in intensive care units but simply kitted out with the right equipment.

This number of just over 6,000 is a long way from the government target of 12,000, set out by the Ministry of Health in August, 2020.

In any case, due to the increase of beds with intensive care unit equipment, the figure 68.8% is slightly too high.

The number of people in intensive care units due to Covid-19 has been steadily increasing since the beginning of the year. It is now above 3,000, set by the government as a target to end the second lockdown in December, 2020.

Check our daily updated article for updates and a more rounded assessment of the pandemic in France rather than focusing solely on the number of positive cases.