Since the beginning of the year, they have been populating the TV platforms of the news channels and inviting themselves into all conversations. "They"? These are all these medical or scientific experts who come to answer questions about the SARS-CoV-2 coronavirus, the Covid-19 disease it causes, its spread, etc. They can be simple doctors, infectiologists, virologists, epidemiologist, or microbiologists or even immunologists.
So many titles that we sometimes confuse, over the debates. Latest example: the charge sent this Thursday, on BFMTV, by the infectiologist Christophe Rapp against the microbiologist Didier Raoult. The latter, now famous for the hydroxychloroquine he praises all over the place, claimed that mortality was five times less high in Paris than in Marseille. "I remind you that he is a microbiologist and not an infectious disease specialist, so we will have to stop marking an infectious disease specialist on the banner, because there are only 80 professors of infectious diseases in France and it's not the same profession", said Christophe Rapp.
"If there is indeed a scientific theme that could interest a large number of academic paths and methodological approaches, it is infectious diseases", smiles epidemiologist Mircea T. Sofonea, joined by Le Parisien. Staff review, supporting concrete examples.
The epidemiologist, the king of curves
What is his specialty? He is called upon to speak about the circulation of the virus within a population. The epidemiologist examines how the virus has spread, since its onset, from hospital data or other observations. In a way, it plays the role of curve modeler and it can also try to predict how the epidemic will evolve.
These scientists are not necessarily doctors, some being academics. They can work in hospitals, in public health agencies (they will also investigate in the field to identify contact chains), or in private organizations.
"My job is to compare, evaluate and above all to develop methods that allow us to extract the most signals from what we observe and to interpret them from an applied point of view (has a virus chances of spreading?) or fundamental (what are the elements that impact the virulence of a virus?) ”, develops Mircea T. Sofonea, teacher-researcher at the University of Montpellier.
What questions is he best placed to answer? Have we reached the peak of the epidemic? How many cases will there be in a few weeks? Does the closing of borders make it possible to limit or even stop the spread of the virus? Among many others ...
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Who are the best known? In the media, we regularly hear or read Professor Antoine Flahault, in Geneva, or Arnaud Fontanet, of the Institut Pasteur.
WHO was one of the first to raise the alarm, but in the West, people were not prepared to face such a pandemic "
Antoine Flahault professor of public health at the University of Geneva @FLAHAULT #ObjectifMonde pic.twitter .com / 0HovUQqwW4
The infectious disease specialist, "Mister Symptoms"
What is his specialty? The infectious disease specialist is a doctor who works with patients with an infection, whether mild or severe, such as that caused by the coronavirus. He is in charge of prevention, diagnosis and management at the same time.
"The infectious disease specialist has two strong points: the detection of clinical signs linked to the disease, such as fever, fatigue or digestive disorders, as well as the prescription of antibiotic and antiviral drugs", explains Stéphane Gayet, infectious disease specialist at the Strasbourg University Hospital .
“The heart of our job is to be daily with our patients to provide them with care. This does not prevent us from having skills in epidemiology and knowledge in virology, but, usually, we do not work directly on it, "says Professor Bouchaud, head of the department of infectious and tropical diseases at Avicenne hospital. (Bobigny).
What questions is he best placed to answer? To those relating to the symptoms and the clinical characteristics of the patients. When should we worry? In which category of patients is there the highest proportion of severe forms? Etc.
Who are the best known? Those most often involved in the media generally run a hospital service for infectious and tropical diseases. This is the case, in particular, of Pr Caumes, at La Pitié-Salpêtrière (Paris), and Pr Bouchaud.
The virologist, who knows everything about the virus
What is his specialty? As its title suggests, a virologist is a specialist in viruses. He studies their specificities, and their functioning. He is most often a doctor or pharmacist and he generally works in the hospital or in a biological laboratory. He can also participate in the screening of patients by virological PCR or serological test, since he is best placed to know how to detect the virus. An immunologist, specialist in the immune system, is also competent when talking about the roles of antibodies.
1⃣ I am a virologist, not a doctor or an epidemiologist. These are the people from these two fields who must be called upon to speak about the current situation. @CNRS, @ Inserm and @ institutpasteur said they put their experts at the disposal of journalists: contact them.
- Tania Louis (@SciTania) March 11, 2020What questions is he best suited to answer? To everything related to the virus from a biological point of view: what is its lifespan? How does it reproduce? Virologists were also often called upon at the very beginning of the health crisis, when there was much talk of the coronavirus without patients having yet been identified on French soil.
Who are the best known? Perhaps the one we have heard the most about in France is the German Christian Drosten, who warned in particular against the risk of a "second wave" in Germany.
And the others ?
But virologists are considered to belong to a larger class, that of microbiologists, of which Professor Raoult is now the best known name among the general public. These are interested in all microorganisms, whether bacteria, mold, but also ... viruses. "The microbiologist is a generic term which designates all bacteriologists, virologists, parasitologists, etc. But as he is, in theory, not able to grasp everything, he often specializes in a more specific field, "underlines Stéphane Gayet, who also has a master's degree in microbiology.
Like him, several scientists also claim to have several caps. On his Twitter account, Didier Raoult also presents himself as an "infectious disease specialist".
"Despite training as a scientific biologist and working on viruses, I am not a virologist or an infectious disease specialist because, beyond the fact that I am not empowered to identify, diagnose or treat viral diseases , the individual scale (of the pathogen and its host) is only a means and not an end to better understand my scale of interest, namely the population, "judges epidemiologist Mircea T. Sofonea.