THE ESSENTIAL
- The virus is more contagious than expected
- More intensive care patients in Italy than in China
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Severe acute respiratory syndrome coronavirus (SARS-CoV-2), the causative agent of the new 2019 coronavirus disease (COVID-19), first reported in Wuhan, China in December 2019 spread to the rest of the world. It seems, compared to what happened in China, that the epidemic is spreading faster and with more serious cases in Italy and Western Europe.
It is the characteristics of this coronavirus, which is more contagious than an influenza, because it is transmitted both by saliva droplets and contaminated objects, which would be responsible for the current epidemic outbreak. But above all, it is the high frequency of severe pneumonia, with acute respiratory distress syndrome (ARDS), especially in the elderly, endangering our care system and intensive care units.
A virus that is easily spread
The SARS-CoV-2 coronavirus has long been thought to spread mainly through respiratory droplets and through close contact. However, since these modes of transmission do not explain all the cases, contamination of everyday objects was then raised.
A first study in a shopping center in China had highlighted the importance of respiratory contamination, and the possibility of contamination via the toilet. Another study by JAMA recently showed that many objects are contaminated in a patient’s room: bed, table, switch, chair, window, cutlery, door handles, sink, toilet … and even blades of the ventilator. air conditioner). So an infected person, even asymptomatic, can contaminate many everyday objects, and even outside his home.
The very sick old Italians
In a Lancet publication, Italian doctors describe the 827 first deaths observed among the 12,462 first infections confirmed on March 11 and the deaths concern patients older than in China. The average age of people who died in Italy is 81 years and over two-thirds of these patients are comorbid: diabetes, cardiovascular disease and cancer, or are former smokers.
Of the patients who died, 42.2% were 80 to 89 years old, 32.4% were 70 to 79 years of age, 8.4% were 60 to 69 years of age, and 2.8% were 50 to 59 years of age (the elderly over 90 years of age accounted for 14.1%). The male / female ratio is 80/20, the median age being higher for women (83.4 years for women compared to 79.9 years for men).
Major use of intensive care units
These deceased people had associated chronic illnesses, but they mostly died from an acute respiratory distress syndrome (ARDS) that appeared in a 2e time, around 7e day of development of atypical pneumonia, with need for respiratory assistance.
An article in JAMA tells us that there was an immediate sharp increase in admissions to the Intensive Care Unit from the first to the fourteenth day of the epidemic in Lombardy. These admissions would represent 16% of all patients tested positive. These data are 3 times higher than those reported in China, but it is likely, given the rapid spread of the virus in Italy, that not all patients have been identified and that some can be attributed to the much older age of patients in Italy because the virus has not mutated.
Acute respiratory distress syndrome
Although most young patients had a favorable prognosis under intensive care treatment, older patients and those with underlying chronic conditions fared less well, with the onset of rapidly fatal acute respiratory distress syndrome (ARDS).
According to another Italian study by JAMA Internal Medicine, the risk of developing ARDS in infected patients depends on their ability to develop an adapted activation of their immune system. However, advanced age is associated with both the development of ARDS and death, possibly due to immune responses unable to clear the virus. This adaptive immune deficiency would lead to a massive release of immune cell recruitment proteins, the “cytokines”. It is this “cytokine storm” that would lead to ARDS, target organ failure and disseminated intravascular coagulation, and then death.
More contagious than anticipated
The severe acute respiratory syndrome coronavirus (SARS-CoV-2) therefore seems more contagious than expected, which is a problem for our open western societies. It triggers serious pulmonary complications, of the acute respiratory distress syndrome type, in particular in people who have an alteration in their immune system (age, associated diseases, immunosuppression, etc.).
These 2 characteristics, contagiousness and frequency of a serious pulmonary attack which will require a prolonged occupation of a resuscitation bed, make it absolutely necessary to reduce the contacts in order not to exceed our hospital capacities, in particular in units of intensive care.
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