Sars, Cholera, Burns M E R discussed on Probably Science
Also evident in certain parts of the Middle Eastern parts of the country. Now so what? Most people don't know that there are still small cases of Burns M E R S. That are out there. But anyway this this New New form of the corona virus. I we didn't know that it was a corner virus. We we had a pretty good guess after this first emerged in China a few months ago and then it was identified and relatively quickly based on the epidemiology and indeed they because we know a little bit about the molecular biology of the of the virus. We were able to actually able to pin down kind of a fingerprinting for the virus relatively early so take take us back to our question here So the current virus is the is the cause for the current current delicious? And the reason that this has been a relatively problematic and that's not necessarily predicted as the final outcome for my chorus is because the other corona viruses that were merged and SARS which had a mortality rates somewhere between fifteen and thirty percent Had a a an incubation period? That was somewhere between five to fourteen days and also it did not appear that individuals that had the virus but were not sick could actually spread the virus to other humans so with the identification of SARS and mirrors and with the initiation of implementation of social isolation but specifically quarantine for a number of days. The SARS outbreak in particular was able to be brought under control because it did not have those other conditions meaning. It was not transmitted before someone knew that they actually have the virus in the eight quote as symptomatic state and secondly because the incubation period tend to be a little bit longer in the five or fourteen days and this virus current virus seemed people can become symptomatic within a couple of days although the median duration of symptoms onset is still at five days. And sorry. Sorry I cut you off piece. There's one more factor that that's that's important to this particular virus again. This is being studied now. And we'll be studying for a long time to come. But the virus seems to have receptors that make it ideal to not only infect nose and the back of the throat but also seems to have receptors. That are a little bit more Able to navigate into the lungs so a variety of the symptoms that are associated with this particular corona virus are more likely to be cough and shortness of breath than necessarily a runny or stuffy. Nose that you might have with a typical cold just to clarify some terms from earlier incubation period refers to the time between contracting and being symptomatic or between contracting and being able to retransmit yeah it's usually referred to as the time between contraction and being symptomatic. Yes okay so this is something that you you've talked about. You talked about in the cool in terms of making a perfect epidemic. It needs to hit the sweet spot. Spits Wayne incubation period but also the fatality rate interestingly for it to be a really dangerous pandemic it can't be too high in to meet you talk about one of the reasons why Boa took wasn't as widespread and dangerous is because people die of it too quickly so it doesn't get passed onto as many people that's correct. That is true that we talk about the course and that is Again there's a there's a virus sweet spot involve several variables Including this incubation period the actual virulence itself but having a a death rate that is somewhere between influenza which is somewhere between a tenth of a percent and a half of a percent although in the nineteen eighteen influenza outbreak. It was. It was likely much higher than that. But having a mortality rate that hovers Under five percent allows the virus to spread and actually favors the transmission of the virus. I I've never quite understood. So what exactly is a virus in because it sort of seemingly less than a Criterium in that. It's it's not. It's sort of semi living. Not really living. It has to share living elements with the host. Okay so virus is a relatively primitive life form but yet primitive but deadly It has genetic material. That's on the inside. That's either deoxyribonucleic acid or DNA or aren. A and we won't get into the technical details of that but then often it's surrounded by an envelope which has a variety of a characteristics which kinda keeps the nucleic acid and the genetic content in the middle and then some viruses have a cap. A capsule in some viruses. Don't again the details of that are not important but we do believe that. The Corona virus is an enveloped virus and hence one of the reasons said alcohol hand gels for example in bleaches are relatively effective on the on the virus. I don't WanNa get too far off the subject here of what you're asking so a virus itself can't really go anywhere by itself. What it has to do is I'd tach to human or other cells and then it is able to gain entry into the cells via a variety of a physiologic things once the surface receptors are triggered. And then it goes into the host human cell and then it tricks the host human cell into feeling that it it's it represents its own DNA Aurigny and it turns on the host Cell Machinery and this leads to actually a reproduction of the virus. And not anything. That's that's beneficial to the to the human host. And then when it's when it's done replicating inside the cell it kind of knocks on the door and it has certain receptors that allows it to to get out into the blood and to spread. So it's really a perfect. It is a parasite if you think of a term parasite see movies with with something. That's called a parasite on a on a macroscopic base. Where you can visually see it or people seen worms and things like that. But this is a microscopic parasite is totally dependent upon what we call the host and the human doesn't have to be human host machinery of the cells to To survive and to propagate you touch to this. I'm more than happy with diversions. We go on diversions all the time on this show you talking about because it's an envelope It's thought to be an envelope Virus that does mean that these alcohol hand gels and I it seems to be relatively easy to kill albeit extremely hard to avoid the spread. So this thing sticking a virus can be spread multiple ways right through droplets through contact G. Do we know. Do we know how much we know so far about how it can be spread in house prevents? It's a good question here. So we know that it to their courses well about transmissibility as another important what we call virulence factor for causing a pandemic so Microorganisms are transmitted by direct contact by touching either one another or touching surfaces. Or what we talk about quite a bit in the courses something called the the fecal oral route and that sounds a bit disgusting but it just basically means that you're touching your own mouth and you may end up introducing something into your intestine and then when you're you know defecating the organism or microorganism can be picked up again as you're as you're doing that. I mean this is on a microscopic basis but Is a holiday is when a cholera is transmitted that way right? Cholera is transmitted that way. Yes yeah and and also a number of bacterial well cholera bacteria but other other things like Salmonella and Shigella and other Back a bacterial intestinal diseases are also transmitted by the fecal oral but there are viruses like hepatitis. A which is also transmitted by the fecal oral route. And but I don't like get off on the fecal route because that's not the major means of this virus spread it is is a direct contact and the contact can also be not directly. Because if there's a well let me get to the second mode of transmission here which is by droplets. So when even when I'm speaking on this podcast now I'm trying to generate my voice and I'm likely generating a small aerosol of very small particles that are traveling on the average a distance of three to the most six feet before these particles will drop and fall to the ground or fall to a table or fall to its surface so if if people are congregating within that six foot radius then they have a potential not by contact but actually to breathe in that aerosol directly into the nose and the back of the throat and the lungs and and and get the virus. If you're talking about a contact I should elaborate that the contact with one another or with a very surfaces. You have to actually touch your eyes or your touch your nose touch your mouth. And what we call inoculate the mucous membranes of the eyes nose mouth in order for the virus to get into the body so the virus is not going to say burrow through intact skin. Just because you touch something to get into the body and this is again why the the common sense of ice has been. Don't touch your face. Don't touch your nose. Don't touch your mouth. Which unfortunately as human beings we are prone to doing because humans touch their touch their face and touch their their their touch their face somewhere between six to twelve times per hour when people have done observational studies regarding this here so it's it's a hard habit to kick so that's spread is by the Aerosol route. The spread is by direct contact or the spread is by contact with a surface which then is touched and then inoculated into one of these the mucous membranes of the of the body again. The eyes the nose or the mouth now. One of the questions that might come up for from listeners is how long can the virus actually survive on inanimate surfaces? How long can survive on a table? How long can it survive on the floor? How long could survive on a grocery box delivered from the Grocery Store? And you know there. There is some information on that although and again this was actually published in the New England Journal medicine the last forty hours but the conditions by which they did the experiments where we're actually experimental so the exact answer is not out there but the the point is the virus likely can survive for somewhere between twenty four hours to five to seven days depending upon what surface it lands on depending on what the temperature is in the room depending upon whether there's any moisture that's on the surface and so so the virus can be transmitted by intermediary a type of objects and. Henson going to point out one that I think is is a pitfall that Fedex and united parcel services have picked up on in that all of our in our electric agents signing for pen signing for for groceries and on these electric boards now Those pens are perfect of vector for one touch another time picking up these things and then people touching their faces amounts. This is not the only one. But this is one of these hidden electronic devices which unfortunately I got a push email from Fedex and talked by..