With the rapid spread of the emerging coronavirus, the concept of a "super transmission", that is, the patient who transmits the virus to tens or hundreds of people, is a topic of discussion at a time when the epidemic is still somewhat vague to doctors, with difficulty in understanding all the factors that lead to transmission.
The concept of a "super-infection carrier" did not arise with Covid-19, but was also used in the spread of the SARS epidemic (2002-2003) and the Middle East respiratory syndrome (since 2012) also belonging to the family of the emerging coronavirus. The term was used more than once when talking about the current epidemic that started in China and spread throughout the world.
Amish Adalja, a doctor specializing in emerging infectious diseases and preparing for global epidemics at Johns Hopkins University in the United States, told "AFP" that the expression "is not a medical expression", but that it is valid to describe "a person who transmits the infection to a relatively large number of people."
Since the emergence of the new virus in late December, at least two people have been described in the media as a "super-carrier" or a "super-publisher". These individuals transmitted the infection to a number of persons higher than the average, which is usually between two and three, due to the absence of preventive measures such as isolation, limitation of presence in clusters, and others.
This applies to British businessman Steve Walsh who returned from Singapore, and formed a source of infection for dozens of people in February, including five in France. The man, who has since recovered and was dubbed "the super-infectious publisher" by British popular newspapers, also transmitted the disease to five people after returning to England.
In South Korea, the title was given to a sixteen woman named "patient 31", who is suspected of transmitting the infection to dozens of people, especially during a religious gathering in February.
But many questions and variables surround this concept, as indicated by a number of experts. How can the patient's own biological characteristics, behavior and surroundings be determined, and thus the people to whom the infection is transmitted or "recipients" of the virus, who may be more likely than others to contract the disease? How can we confirm that one person was the source of dozens of cases of infection?
Another unknown factor in this regard is the role of children who are not susceptible to severe infection of the disease as well as other groups, but who are carriers of the virus. And out of the concern related to the ability of children to transmit infection to a large number of people in several countries, including France, the measure was taken to close the schools.
The head of the Department of Infectious and Tropical Diseases at the Pettiere Salpetier University Hospital in Paris, Professor Eric Com, confirmed last Thursday evening to the «LCI» channel that «the presence of what we call the super carriers of infection is possible, and this means patients who transmit the infection is not for two and three ... It is for dozens. ” He added, "The problem is our inability to identify them."
In turn, the head of the Infectious Diseases Department at Avicenna Hospital in Bobigny, Professor Olivier Bouchon says, "It seems that some patients, without this being linked to the strength of the symptoms, secrete the virus more than others and thus transmit it more than others."
He adds, "This is not a hypothesis at present, and we certainly do not have a clear explanation at this stage, and it is not a characteristic of the Covid-19 virus alone."
"We are all different, from our immune systems, our behaviors, and the places we go," concludes the professor of epidemiological statistics at Imperial College in London and Oxford University, Christel Donnelly. All of these elements can play a role in relation to the number of people to whom we transmit infection. Biological and behavioral factors can influence, but also time and space.
The ambiguity surrounding the concept led Doctor Bharat Phankhania, an infectious disease specialist at the University of Exeter’s Medical College, to say that “the super carrier of infection does not exist.”
He considered that this term is "inappropriate", adding, "What we have seen is that the conditions have led to the transmission of infection to more people," speaking in this context of the "patient 31" condition in South Korea.
He explains that the infection is transmitted "often between the crowds, in closed places where there is no ventilation, or because an injury is not recognized ... and often through a person at the beginning of his illness, when the secretions associated with the disease are at its maximum."
For these reasons, many prefer not to talk about a state of "super transmission" or to classify someone as a "super diffusioner" for it, a term that French Health Minister Olivier Ferrand considered "stigmatizing" the people concerned.