The latest report on the Covid-19 epidemic shows an additional 231 deaths between Tuesday and Wednesday, bringing the number of deaths in hospitals to 1,331; 311 new patients are in intensive care, bringing this figure to 2,827 people, a third of whom were under 60 years of age.
The doctor Gilles Pialoux, infectious disease specialist and head of the infectious and tropical diseases department at Tenon Hospital in Paris, answered questions from readers of the World, Thursday March 26 during a live chat.
Gudule: Do we know the proportion of asymptomatics among the elderly? Or in other words, are there more risks of triggering symptoms with age?
No, we will not know the proportion of asymptomatic[[who have no clinical symptoms]only when there are serological tests (antibodies) coming up. Children are more asymptomatic and the elderly more at risk of mortality and serious forms.
Confined: At ten days of confinement why the “wave” is expected, should we not already see a recession begin? How long does it take to notice a decrease in cases thanks to containment?
For a measure such as containment to be effective, it is necessary to wait for the maximum incubation period, approximately fourteen days. It is possible that the escape from the confinement rules is, for example in Italy, an explanation for the absence of a recession. But it must be understood that this decline is the result of the power of measurement and the progression of the epidemic.
Geoffrey: What is the immunity observed in China? Will it be like a flu that will need to be vaccinated every year?
We don’t know, we have to wait for the serological studies that will come after the epidemic. But Covid-19 appears to be a fairly stable virus, unlike the flu virus, especially in its envelope which is the preferred target for antibodies and therefore for a future vaccine.
Roman: The French curve of deaths seems to follow very closely that of the Italians, should we expect a similar number of deaths?
I think we are indeed following Italy, but everything will depend on our ability to absorb serious forms in intensive care. In Ile-de-France, more than 2,000 patients in intensive care are expected – but the forecasts are difficult with the Covid-19 – for a current capacity of 1,500 places in critical care. So we will have to transfer, as was the case in Lombardy. Often more than 150 kilometers from the original hospital, or pushing the walls further by transforming post-operative recovery rooms into resuscitation beds. We hope to have enough respirators. But you also need to be able to resuscitate and operate on other urgent patients.
Guigui: Do we have more information on the impact of the season on the transmission of the virus, as we can see on the seasonal flu? Are we seeing in the southern hemisphere? On the other hand, is there a link between the degree of exposure and the severity of the Covid-19? Can increased or repeated exposure lead to more serious effects of the disease?
The expected impact is minimal. The virus supports temperatures up to 65 oC and circulates in the southern hemisphere and in Africa.
Regarding a possible link, we do not know, but our experience is that some patients have a very high viral load and are “Super contaminators”. As in SARS. This was the case with our patient zero at Tenon, detected late because he did not return from a risk zone and who infected several caregivers, other patients and family members before being screened.
Pascompris: I have heard of “self-tests” that would be sent to homes in Germany or England, I don’t know anymore. Is it something realistic? on the assumption of a deconfinement, how to make sure that the individuals carry out well their test, and isolate themselves in the event of positive results?
Yes, I have a model in my office. But we have to wait for the evaluations. These are antibody tests that do not initially detect infection. What is needed are rapid virological tests! It is under development.
Question PLEASE: Is it possible to remember how the contamination of a healthy subject happens? When can this subject infect others? How long can this subject heal?
The incubation period is in practice quite short, three to seven days. By definition it is considered that a person is contaminating twenty-four hours before the onset of symptoms and for fourteen days, but in some cases the virus is present longer … up to twenty-one days.
MGavecpeudinfo: Can you give us details about the risks for pregnant women?
This is a difficult question. No known maternal-fetal transmission but contaminations by the entourage of newborns without serious forms. The focus is on third trimester surveillance and hospitalization for fever. In publications there is an increased risk of abortion and prematurity with MERS-COV and Covid-10. But there is a lack of data. Obstetrics teams must be trained to manage the Covid-19.
Con in fine: The virus dies on surfaces where it cannot replicate, but is it the case on food? After how long can you eat a raw food (fruit, cheese, meat, etc.) that you might suspect to have been infected?
The virus remains on the surfaces surrounding the patients for several hours, without it being known when the doses found by PCR are no longer contaminating. It’s like HIV. Chinese studies show that in a sick room, in twenty-four hours all surfaces are contaminated.
Catherine: Private clinics say that they are not contacted when they have organized themselves and have resuscitation beds available: how does the coordination between public hospitals and clinics work?
This is wrong, this weekend in Tenon we “emptied” our specialized units towards the private sector, which plays the game, it has recently been true, but they are not always equipped: masks, overcoats, SHA, charlottes, etc. There are even private resuscitations which begin to take patients, whatever their social cover!
Pasteursauvenous: Why do the announcements seem so positive about a vaccine? AIDS has existed for decades and there is no vaccine. Ebola which is much more deadly … no vaccine. In short, there are a lot of horrible viruses that can’t find a vaccine. Why does everyone seem so positive for coronavirus?
Because it is a fairly stable, non-hypervariable envelope virus like HIV or the flu virus. For HIV, the genetic makeup of the virus varies by 30% possibly from one individual to another or in the same individual over time. We’ll get there with the Covid-19, it just takes time.
PCPC: Once the containment has been put in place and the return to “normal”, can we expect a second wave of contagion? Some experts have suggested that this will happen in China.
The figures deceive us: we only detect in France as in China, I believe, forms in people who need to be hospitalized, symptomatic people with serious factors and caregivers. The only reliable numbers are mortality and resuscitation. The second wave is possible either by loosening the confinement or by wave effect on patient contacts.
PP: Could you repeat a point on the usefulness of masks? We have heard a lot of contradictory things on this subject, I am a little lost!
The surgical mask with elastic or string is to protect yourself and especially protect the other from splashes in case of symptoms. FFP2 is reserved for caregivers, firefighters, emergency medical services, etc. for risky maneuvers with sick or suspected people. In both cases, we manage the shortage, which is shameful, whatever the cause. Readers of World, do not store! There is no point in walking your dog with it. And don’t forget the other barrier measures: sneezing in your elbow, washing your hands, using SHA, disposable tissues, etc. And then we have so many flights on Tenon, operating theaters that are forced at night, to delivery trucks pointed! Please !
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