Contagion more rapid than thought

Now, much of the literature that appears on the covered 19 is not peer reviewed at this time and this is because the peer review process takes a bit of time and this is an example of a paper that is not peer reviewed peer-reviewed, but it still has quite a bit of academic credibility and it's called the 2019 novel coronavirus, it's highly contagious and

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infectious than initial estimates, so it's a little surprising how quickly this virus has traveled around the world, the virus covered 19 and this article helps us explain. that, but

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importantly than that, it gives us some practical ideas to reduce the speed of propagation and this comes from a group of academics at the National Laboratory in Los Alamos, which of course is famous for its work where the first nuclear nucleus is located.

The pump is developed now, start with a good review. In fact, I think we took the time to go over this because it's interesting now, at the end of December 2019, 41 cases of pneumonia of unknown etiology, that's the American spelling, of course, it's an American article. were stuck with the American spelling were reported by the Wuhan Municipal Health Authority, so there was no pneumonia of unknown etiology, so it was like a new type of ammonia that didn't seem to fit into any of the existing categories and was consistent with known types of viral pneumonia. but it was basically a new unknown type of pneumonia now, on the first of January 2020, the wholesale market of Hunan Complete Seafood Market in Wuhan was closed now this market you will know if you watch previous videos, but this is one of these Chinese markets where they sell live and dead animals, sacrificial animals on site and they also sell wild animals that have been captured to eat so you can buy pieces of snakes and fish and all kinds of things and there are also things that we use are used in Chinese Medicine It is not good at all for Western tastes and it is very bad from the point of view of the transmission of this disease because the virus is zoonotic and comes from animals, but it was suspected to be an epicenter of this infection and now it is basically believed that it was the epicenter from where this infection came from animals to humans is sweet Renata now on January 8 the China Center for Disease Control identifies this new virus and at that time they called it new coronavirus 2019 on January 15 Update China Center for Disease Control at emergency response level 1, the highest response, what evidence of human-to-human transfer, so this time they started to realize it, so it was taken as if it was the end of December and the human transfer is recognized on the 15th.

The tragic thing is that the evidence was presented. by local medical staff at that time was suppressed by local authorities, which was terribly tragic now, on January 15, the SRO improved for humans to demonstrate, and on January 21, 2019, inspiration and infection of the new coronavirus had spread to most other parts of China, so it had basically spread pretty quickly on January 23, the city of Wuhan was locked down. People were not allowed to enter or leave because they realized that the epidemic was spreading from that city of Wuhan in Hubei province and really the timing couldn't have been worse because this was right in the middle of the New Year Festival.

Chinese New Year, the spring festival or the New Moon Festival, and it is the most important holiday in China, so there was a lot of coming and going now, on January 30, the World Health Organization declared the outbreak as a public health emergency of international concern there the words that use that was January 30th now at this time the r-nothing was estimated to be 2.2 now what this means is so if we imagine that initially there was a person who had this infection then the R zero is the average number of people a person in fact, so if the R zero is two, then that person would infect two more people, but then each of these people would infect other people in turn and then Of course, each of these. could infect two this way, so on average we see that each person is infecting two people, so this person infected two people, that person infected two people, that person infected two people, this is how works, it would be an hour north of two and this is an average hour of the estimate the estimated average transmissibility of the virus how transmissible it is so clearly in Arnor was three so one person could go on and infect three people and then each of them could infect three on average and then each of them would infect on average three more, so you can see that the epidemic is going to grow much more quickly, so this figure from our North, this average figure of how quickly it spread the disease is actually very important to map an epidemic and predict the course of an epidemic now the initial one.

R zero estimates were pointing to around 2.2 and that represents a doubling time of 6 to 7 days. I think you should aim for around 2.6, so around the 2.5 mark would actually be a doubling time between 6 and 7 days. 7 days that was the initial estimate, but what this group has done in Los Alamos grew through a group of mathematical modelers from a mathematical center of very high reputation and they have carried out a new analysis of the data up to February 5 and the number of infected people. during the initial epidemic the estimates doubled every 2.4 days, so when they looked back at the data and had more complete data than the people who calculated these inferior Arnauts in pairs originally had, they collected more data, They collected many individual sample pieces of The data from the epidemic area used epidemiological principles and mathematical models and there is nothing that results in 4.7 between four point seven and six, so what they say is that in the initial stages of the epidemic the growth in the number of cases was much higher than had originally been estimated and from this they concluded that because you see what this means is that if the Arnauts were four point seven to six point six in the early stages of the epidemic, that It means that the characteristics of this virus can generate Arnauts.

Of these values, this virus has the capacity to double its capacity or double the number of affected people every 2.4 days, giving these Arnauts from four point seven to six point six, so if R zero is six, on average each infected person is infecting six more people, so it will spread much more quickly and from this they concluded that strong control measures were needed to stop the transmission of the virus, which is interesting because what this means is that, you see, the R nothing does not It is intrinsic to the nature of the virus. zero is an average figure of the actual spread that took place, so this is a retrospective analysis that resulted in these two figures looking back and because R zero is not intrinsic to the nature of the virus, it depends on the nature of the virus. but it also depends on the control measures that are taken, so if good control measures are taken, it will spread less quickly and the R nothing will decrease if, as in the early stages of this epidemic, it was not taken seriously and not there were effective control measures, then the Arnauts are going to increase, so that was the conclusion they came to, but also by looking at this data mathematically from a retrospective point of view they came up with other interesting points, such as the time since exposure initial until the onset of symptoms, so the initial exposure. to the organism to the virus to a set of symptoms they that their figure was 4.4.2 days on average that was the average of three point five to one to one days the average incubation period now we know that the incubation period can be less than We know it can be much longer, two to fourteen days, we're still saying, but they were saying that most people were in the market incubation period of four to five days and then they watched the onset of symptoms until hospitalization. and what they found here that before January 18 the average time from the onset of symptoms until a patient needed to be hospitalized title of onset of symptoms Hospitalization the average figure was five point five days and after January it dropped to one dot five days, so there's a there's a big difference there and this p value is less than zero dot zero zero 1 means that your results are almost certainly genuine and didn't arise by chance now what's probably happening here is that more People were becoming aware of the virus after January 18, so they knew they were sick with this virus, so they showed up for hospital care, so it's probably a difference in public awareness there rather than a change The other interesting thing we found was that the time from initial hospital admission to discharge was 11.5 days on average, between 8 and 17, point 3.

Most of the cases were because of this, what this means is that most of the cases were within this range. I think 95% of the cases. was within this range, but I gave an average of eleven point five days of hospital time and what they also found was the time from initial hospital admission to death for those people who died again. 95% of the cases were between one point seven and fourteen point nine. days, but the average was eleven point two days and they concluded that control efforts have a measurable effect on the rate of spread and we have actually seen this in China, so the rate of spread was relatively high and yesterday you may have heard me read That letter was sent to someone you already know, not in Beijing or, as he called, not in Beijing, in Beijing and, um, they said the city is basically closed, all of China is pretty much closed to a lot of comings and goings in normal daily life and This is reduced social interaction and of course this has greatly reduced the r-nothing, the spread has slowed down a lot, but perhaps later today we will see the situation in Iran, where we do not There is no lockdown and therefore we expect the spread to be much faster, so the moral of this story is that control measures can make a big difference to the rate of spread, so these are just some facts to give evidence that control measures are absolutely essential throughout the world. and as I have said many times, we are now in the early stages of a pandemic and these control measures must be implemented anywhere there is evidence of the virus, for example this is starting to happen in Italy, although unfortunately they have still spread.

I think Sicily and places in the south of Italy also from the north, but the best thing is that the best defense we have at the moment is to slow this down, contain it and hope that we can delay the start of the pandemic so that we are more prepared, with luck. a vaccine hopefully with medications hopefully with better control measures ready to implement