Source [Atlantico] Epidemiologist Marc Lipsitch of Harvard University in the United States has said that the coronavirus “will ultimately be out of control” and that it will infect up to 70% of humanity within a year. Why is it so difficult to contain the epidemic?
Atlantico.fr: According to epidemiologist Marc Lipsitch, the coronavirus epidemic will not be contained and will infect “40% to 70% of humanity”. Can Covid-19 really spread on such a scale? Why is it so difficult to contain this epidemic?
Stéphane Gayet: Marc Lipsitch is a professor of epidemiology at Harvard University (in Boston, the dean of American universities). First, a terminological clarification: we ask to name this current virus SARS-CoV2 and the disease produced by this virus CoVid-19. SARS-CoV2 to distinguish it from SARS-CoV, the very first coronavirus identified to be responsible for an epidemic of severe lung infection. Because until then, coronaviruses were known as infectious agents of colds and mild airway infections. They were (are) better known by veterinarians and breeders, in particular for causing acute feline viral peritonitis with coronavirus (abdominal infection, sometimes severe, common in cats).
It should also be noted that the acronym SARS is French (severe acute respiratory syndrome) and the acronym SARS English (inversion). CoV simply means coronavirus (one of many families of potentially pathogenic RNA viruses).
Thus, after the epidemic of 2003, also appeared in China, of severe acute pulmonary infection with SARS-CoV, here we are for a few months confronted with a new coronavirus named SARS-CoV2, therefore also appeared in China. To say that these viruses “appeared” in China is an improper expression: they emerged in this country. These are zoonoses, which means that these human infectious diseases are caused by infectious agents from animals.
The same is true for yellow fever, Ebola virus infection, human cases of avian flu, plague, Lyme borreliosis and many other infectious diseases. This is an opportunity to say that this current epidemic of coronavirus pulmonary infection is unleashing rumors and writings on social networks where we can read a lot of untruths written to manipulate or panic people. In France, the most reliable sources of primary information (raw information unshaped to be catchy) are the websites of the Pasteur Institute, Inserm, Public Health France as well as that of the ministry responsible for health. It is distressing to see how many people write maddening and irresponsible nonsense on social networks, with the aim of making themselves interesting.
Marc Lipsitch compares the SARS-CoV2 epidemic to the SARS-CoV epidemic (2003), but also to lung infections caused by the avian A-H5N1 virus. The mortality rate for CoVid-19 is less than 2%, that of the SARS-CoV epidemic was 15% overall and 50% in subjects over the age of 60, while that due to infection with avian influenza A-H5N1 virus is approximately 60%. By comparison, the mortality rate from seasonal flu is very much less than 1%.
Interviewed by James Hamblin, a medical reporter for The Atlantic, he develops the thesis that this SARS-CoV2 epidemic is dangerous because it is not serious. According to him, when a respiratory (viral) infection is serious, the patients are easily and quickly identified, hospitalized and the secondary prevention measures are effective. On the contrary, when it is not serious, many patients circulate and carry out activities, which gives them the opportunity to widely disseminate the viruses in the population and this in an imperceptible way.
Marc Lipsitch’s remarks must be qualified with the notion that there is a fairly low contagiousness of CoVid-19.
The fact remains that the American epidemiologist believes that the SARS-CoV2 virus has already started its dissemination in several populations and in an apparently invisible way. There is another weak point in his theory: sick people spread their virus mainly through coughing and sneezing. Cough is the functional sign of lower airway infection and the essential mechanism of spread to others. In the case of an individual who is asymptomatically affected (sick), and therefore of a subject who does not cough, dissemination can only take place through speech (and shouting); however, the power and range of aerosols emitted by speech are much lower than with coughing. This means that in the absence of a cough, there must be close proximity, therefore a very short distance between individuals. And it should also be added that the intensity of the production of viral particles is linked to the intensity of the infection: the sicker one is, the more contagious (to a certain extent).
If Marc Lipsitch were to say the truth, that would mean that there are already contagious people who are apparently not sick and who could widely spread the virus. In this case, the epidemic would be very difficult, if not impossible, to contain, as the epidemiologist states. This is his thesis and we will see if he was right.
Find the full article by clicking here