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Current time:0:00Total duration:11:23

Video transcript

let's say you've got two people and one person has tuberculosis that's this person over here I'll call them person a and another person does not this is person B over here so what are the things that are going to make person a more infectious what are the things that we need to think about in terms of how likely it is that person B will actually get sick with TB well there are a few things so we know that this person has to actually call out some TV particles right they're going to cost them out and that means that the strength of the coughs oh let's say they have a real good coffee versus a really weak kind of puny cough something like that is going to matter and it turns out that the folks that have the strongest cough are the adults so any adults in general adults are going to have a much stronger COFF than children so that means that adults are more infectious than children so let me actually write that as my first key point and it turns out that's exactly right that we see that in terms of spreading TB it's the adults that spread it much more than kids and definitely much more than infants now a second point is that you need live bacteria right this seems obvious that of course you're not going to get anyone sick if you don't have live bacteria and the way to know that someone has live bacteria you can actually just take some of their sputum or some of their mucus from their lungs and look under a microscope and you would actually see what we call a positive smear and that literally means you smear out the the mucus under a microscope and you look with a microscope and you can literally see the TB bacteria you can also do a culture and see if you can actually grow the bacteria so if you can see the bacteria or grow the bacteria that's a good indication that there is a live TB bacteria there and that's obviously going to make the person more infectious as well and the third point is if you look in their lungs and you see large cavities sometimes you call that cavitary disease but let me just write cavity here you see a cavity there and that cavity we know is going to be full little TB bacteria those cavities are classic for that and so whenever you see or think about cavities I want you to remember that the folks that get cavities are the secondary progressive disease folks remember there is primary in there secondary and it's the secondary progressive disease that causes these cavities so these are the folks that are going to be more infectious because they're loaded with live TB bacteria so what are the things we can do to actually prevent the spread of TB and the first one is actually kind of obvious it's medication so we have medications that are really good for treating tuberculosis and one classic thing that we've done is what we call directly observe therapy do tea directly observed therapy and all that means is that sometimes a physician or nurse will actually watch a patient take their medication so that they don't forget or sometimes people don't like to take their medications this is an easy way to make sure that someone's actually taking their medications and we call it do tea and so that's obviously going to be helpful for killing off the bacteria so we don't have to worry about live bacteria anymore and usually that happens in about two weeks after two weeks of medications that usually kills off the bacteria so you no longer have those positive smears and positive cultures and also helps with symptoms right so if you're not sick with TB you may not be coughing as much so that's another important thing to keep in mind what else would be important well you could imagine isolation right making sure the person is actually isolated so isolation is key and specifically want to make sure that they're not around any young people so definitely don't want them around anyone under the age of four years because of course children are really really susceptible to getting very sick with TB so you want to make sure they're away from young children and you want to keep them isolated at night so at night when they're sleeping I put a little @ symbol but at night when they're sleeping you want to make sure that they're isolated maybe sleeping in their own room so of course it's ideal if the person is completely isolated but of course that's not always practical as they might be with their family or their children but you want to make sure that they're at least away from children under 4 and at night that they're sleeping alone another thing is a surgical mask so a surgical mask is really good because it helps prevent too much of the stuff that's coming into your mouth to enter the air and actually literally let me just draw it for you it literally catches a lot of the stuff and prevents it from entering the space around you so this is a mask let's say a surgical mask it might hook up like this maybe like that and what it does is it literally catches the stuff that's coming out of the mouth and makes it ricochet back in you can still breathe with a surgical mask on but it just kind of keeps the large particles maybe large droplets from leaving your mouth now what if your person be what's one thing you could do if your person be well one obvious trick is just standing further away you don't have to stand so close to personally you could stand all the way back here and that's going to make it less likely that you're going to get sick with TB so let me write that here is create space create space now another key idea is think about what happens when someone passes gas or there's a horrible smell in a room what are you going to do usually people are going to find the door or maybe they'll open the door and let some air in this arrow indicates more air coming in maybe there's a window here they're going to open the window let that breeze come in basically do it whatever you can to kind of dilute out that horrible smell if there's a fan maybe it'll try to turn on the fan and get that spinning and if you can get the fan going that's also going to move around air you're just trying to move around air to get a dilution of that horrible smell let me write it out dilute and the idea here is you can just literally do simple things you can open up doors and windows we call that natural natural ventilation you can also turn on a fan to kind of move air around and you're just trying to dilute out that horrible bacteria so that less it is likely to enter your lungs another thing you can do is actually put on an air purifying respirator an air purifying respirator is actually a little bit different than the surgical mask this one is actually going to keep out very tiny tiny particles so unlike the surgical mask which gets kind of the large things and spit and you know large particles this one is actually going to capture very tiny particles and it's actually not going to allow them into your breathing area your airway so it's actually going to make things bounce off essentially or get caught inside the filter itself and it won't allow TB particles into your nose or mouth and a common one here that you might have heard of or seen is called the n95 there are many other types as well but that's one example of an air purifying respirator now a couple more things that you might see that are slightly more expensive but you might come across them or at least hear about them one is called ultraviolet ultraviolet germicidal let's see if you can kind of guess how this works or what it does germicidal sidle means killing something germicidal irradiation irradiation and a lot of times people just shorten this whole thing to UV gie they'll say well UV GI was installed and what you vgi does it literally takes ultraviolet light and shines it out and actually if there are a couple of TB particles that say one here one here that UV GI that irradiation kills that TB particle and exces it out and so it's no longer alive and and the folks in that room are safe so then the final thing I want to talk about is called a HEPA filter it's a filter and if I was to draw the ceiling it would look something like this maybe it has some spot on the ceiling where air is flowing in and some spot where air is flowing out just erase these parts right here and I'll show you let's say that air is coming in this way let's say three arrows and you've got air coming out this way you've got three arrows so in the middle somewhere in this area you've got a filter and this filter is going to catch TB particles and so we call it a high-efficiency efficiency particulate air filter particulate air filter and no one wants to say all this because it's too long and so just for short again they say H E P a HEPA filter so a HEPA filter is going to then catch some TB particles are going to flow in and they're going to get stuck in these filters right and so coming out on the other side you have nice clean air because the TB particle will not get through that filter and you could even take this a step further you could say well how about if we did this and actually instead of having all of the air returned let's say we returned just part of it and actually we allow some of the air to kind of escape outside of our room right well now you have a negative pressure in this room right because you have more air leaving the room that is reentering the room you have negative pressure almost like a vacuum right because all this air is kind of going up into the filter and not as much is coming back out so this room becomes negative pressures kind of a vacuum in this room and especially if you do it right if you close off all these doors and you close these windows then you definitely create a negative pressure and what that means is that now you can really protect the area around because you close off the door you close off the window and now there's no way that a TB particle can leave and go into the hallway because if there's a little bit of a gap underneath this door if that's the only crack in this room then the negative pressure is going to make air flow through that crack into the room instead of air flowing out into the hallway so that's actually another key trick that they use to prevent TB from spreading is they'll create a negative pressure where they pump air which is what we showed here and then they'll seal off the whole room and then the air from the hallway starts entering the room and you can make sure that no TV particles are going to get out into the hallway and get people in the hallway sick