At the bottom of the eighth wave of infections, for some weeks now it has seemed almost impossible to accurately monitor the evolution of the epidemic in France.
Labor strike, insufficient screening, outdated tracking system… For almost a month, several factors have disturbed the interpretation of data relating to the monitoring of the coronavirus epidemic in France, whose eighth wave of contamination has reached its peak around mid-October.
Despite the truce, the health authorities continue to raise awareness among the French of respecting the rules of isolation and barrier gestures. “Even if the epidemic situation has been rather calm for three weeks, one person still dies of Covid every ten minutes in France,” Health Minister François Braun recalled last week with our colleagues from the Parisian.
For his part, the government spokesman, Olivier Véran, has again recommended that BFMTV wear a mask on public transport.
Laboratories on strike
To date, the data transmitted daily by Public Health France (SPF) is not alarming at first sight. For example, an average of 23,066 cases were detected per day on 14 November, compared to 27,488 on 9 November.
But the strike, between 27 October and 2 November, by most of the medical biology laboratories – responsible for communicating the results of PCR tests – had “the consequence of interrupting the production of virological indicators”, SPF specified in the its epidemiological report of 10 November.
The laboratories do not agree with article 27 of the 2023 social security financing law with which the state asks them to pay 250 million euros a year. It is a question of compensating for the considerable turnover recorded since the beginning of the coronavirus pandemic thanks to the numerous antigen and PCR tests carried out.
“The fog in French health monitoring has thickened again recently with the strike movements of biologists,” analyzes for BFMTV.com Antoine Flahault, epidemiologist and director of the Institute of Global Health of the University of Geneva.
Because a new strike movement has been launched since Monday 14 November. It must run until Wednesday 16 November, but could very well be renewable. Added to this are the recoveries due to the two public holidays in November – during which much fewer tests are carried out – which blur the trends even more.
However, SPF defends itself and believes that “the dynamics of antigen tests alone (which represent more than 50% of the total number of tests) is highly correlated to the dynamics of all tests”, and therefore allows more or less precise monitoring of the epidemic.
The uncertainty around BQ.1.1 and the decline in the number of tests
However, the absence of transmission of PCR test results implies a vagueness on the analysis of the propagation of Omicron subvariants in the French population. This is the case with BQ.1.1, which has been progressing for several weeks and could soon be the majority, whose SPF proportion could not establish in tests carried out due to “too low a number of sequences to have robust proportions”.
Furthermore, the number of tests, as well as laboratory strikes, also raises questions.
“For several weeks in France it has no longer been possible to follow the evolution of the pandemic due to the collapse of the practice of PCR tests, even in hospitals”, continued Antoine Flahault.
In its November 10 weekly test follow-up report, the Department of Research, Studies, Evaluation and Statistics (DREES) indicated that “the number of validated PCR tests between November 2 and 6, after these disturbances, is 24% lower than the period between October 19 and 23, two weeks before, before the riots”. Knowing that the number of tests (antigens and PCR) is already at very low levels: 106,192 tests performed per day on average on November 11 against 216,416 on October 12 or 1,385,698 on January 15 – during the strongest wave of contaminations.
A questionable system
Beyond these specific difficulties of the current period, the French monitoring system is criticized by epidemiologists.
“Test monitoring no longer really allows you to follow the epidemic,” Dominique Costagliola, an epidemiologist and Inserm research director at IPLESP, complained to BFMTV.com.
She is joined by Antoine Flahault. According to him, “France has not had, since the beginning of this pandemic, tools that allow it to carry out reliable epidemiological surveillance of Covid”.
He then takes the example of the United Kingdom which has “knowing how to set up and maintain a permanent survey on its population, in which they take samples and carry out a survey that gives a more precise picture of the country’s epidemiological situation”. Or again the Netherlands and their “daily virological monitoring system by sampling the waste water of 350 purifiers distributed throughout their territory”.
The epidemiologist then praised their “intensive strategy of sequencing the identified viruses which allows them to carry out an almost real-time mapping of the evolution of the variants on their territory” while France “is sinking into an ever thicker fog”.