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Current time:0:00Total duration:10:53

Catching and spreading the flu

Video transcript

so today's January 11th 2013 I'm just going to circle the date on my little calendar here and let's say I came home from work and I just felt really lousy just awful you know fever sore throat coughs body aches you name it this is the first day I've been feeling like this and up until now you know since the new year started let's say I was feeling really great you know I had no symptoms I was going to work feeling myself right so all these days I was feeling good and then all of a sudden the 11th hit and I just got you know all of a sudden these symptoms right so I I'm already kind of suspecting the flu based on what we know it kind of started abruptly I've got the the symptoms for it and a few questions start popping up in my head I mean the first question I want to know is you know when can I expect to start feeling better right that's usually the first thing people want to know so let's think about what we know about the flu in terms of how long the symptoms usually last because that's going to help us predict when I can expect to start feeling myself again so we know that usually symptoms last for let's say three to seven days so I'm going to say okay you know all these days I'm going to expect to feel kind of the same maybe you know I might start feeling a little bit better by the 16th or 17th but that would be seven days so these are the days I can expect to feel kind of lousy and on average I should start feeling myself again maybe by the 18th and 19th I should start feeling kind of the the way I normally do so according to this calendar I would start feeling better by January 18th that would be my kind of target date and this is an exact right this is kind of just a rough idea so what's the next thing that people usually try to figure out about the flu they always want to know who did they get it from they always kind of want to figure who the culprit was who gave the flu to them so I'm no different I want to know who did I get it from and so I think back and I say well you know I felt good on the 10th and I felt pretty lousy on the 11th and your instinct might be to say well of course I probably got it on January 10th on Thursday but in fact you have to go a little bit further back you know sometimes you can get it back as far as four days so I'm going to circle the day that I could have potentially gotten the flu from somebody and it turns out it could have been any time this week so I'm going to write that down so January 7th to January 10th that's kind of the window in which somebody gave me the flu now how do I know that I got it from somebody maybe I got it from the doorknob or maybe I got it from you know the remote control that someone was touching and those kinds of environmental objects sometimes you can get diseases from there but with the flu you generally get it from another person and the reason is is because you've got this RNA that's protected by an envelope remember this this green layer here this double layer is a lipid or a fat bilayer it's got two layers of lipid or fat and this is what we've been calling our envelope right this is the envelope now because it's got an envelope it means that the virus is actually more sensitive to the environment the main way then that the influenza virus that'll get you sick is when you get it directly from another person because this envelope actually makes it very sensitive to the environment it doesn't really do well when it's out in the environment by itself so usually you get it directly from somebody maybe they cough or they sneeze maybe they get it on their hands and they shake your hand usually directly from another sick person so really if I want to know where I got it from I got a brainstorm and think you know who did I encounter between January 7th and January 10th that was sick now I also want to know who could I have given the flu to you know I'm a conscientious person I don't want to give the flu to other healthy people if I can avoid it it turns out you can actually spread the flu I'm going to circle it in purple here one day before you even have symptoms so on the 10th of January this is the day before I was sick when I was actually feeling really healthy I could have already be spreading the flu to other people on that day on January 10th and of course all these days when I'm sick I can also spread the flu and that's more intuitive because you know I've got sneezing and coughing and other symptoms but the interesting one is that on January hence through the 17th I could have actually spread the flu around the January 10th which is again a day before my symptoms through the 17th I could have started spreading the flu so to know exactly who I gave the flu to I've got a really brainstorm and think well who did I interact with on January 10th right starting with that date well of course I see my family every day right so family and you know I'm a I'm a worker an employee so my co-workers I would see them and there are other folks too right like friends I may maybe not yet but perhaps I might have dinner or meet up with some friends or I might actually even see some strangers you know sometimes I like to take the bus and I may see some strangers or I might shake someone's hand randomly and so these are all the different folks who I've got a brainstorm and think about in terms of who I might give the flute or who I might have already given the flute - maybe yesterday - anyway 10 so now let me actually bring up a little bit more canvas make some space and think about these groups of people who I may interact with you know in terms of family you know for me my closest family is my fiancee so I live with my fiancee and I'm going to draw a picture of my fiancee here and my fiancee is generally healthy and so that's her right there and then of course there are some other folks let's say some co-workers maybe maybe I have a co-worker I'm going to do in a different color who is over here also feeling pretty good and looks healthy but actually has diabetes you know has diabetes which is an important medical condition and let's say I have some family friends I'm going to draw a friend here here's my friend and my friend happens to be pregnant right now so this is my friend and she is pregnant over here and she's got of course then a little fetus inside of her so this is my pregnant friend and my pregnant friend let's say has a two year old daughter so a little two-year-old daughter over here two year old and my friend herself pregnant so I've got my co-worker with diabetes I've got a pregnant friend and a two-year-old daughter and finally let me actually go to strangers let's say I was actually on the bus or maybe I'm going to ride the bus and here's a stranger on the bus and this stranger is in a wheelchair this is a wheelchair here so this is a stranger who's riding on the bus with me one day and perhaps I help her off you know and she thanks me by shaking my hand so perhaps this elderly lady shakes my hand and she's a stranger to me but now I've potentially given her the flu as well so while I had the flu I actually came into contact with some people that we would consider high-risk right I've drawn for you now someone with a comorbidity which is diabetes meaning they have some medical condition someone who is pregnant a young child and someone who's very old and of course over here we have my fiancee and she's healthy and you know has no medical conditions but do you think she's going to be too happy if she finds out that I gave her the flu probably not right so she's not going to be too happy with me either so it's really important for me to keep all these different people in mind and know that I don't want to give other people the flu especially people that are high-risk these are high risk individuals high risk so why do we care so much about these high risk individuals well it's because they develop complications of flu and this is what it really boils down to you remember we initially talked about kind of all the hundreds of thousands of people in the US and around the world that get hospitalized for the flu and then the numbers of people that die from the flu well the overwhelmingly it's people in this group this high-risk group and the things that they get the kind of complications they get are or many actually flu leads to many different types of complications and I'm going to draw out just a few of them for you I don't want to give you an exhaustive list but I want you to at least get an appreciation for the kinds of things we're talking about so for example let's say these are your songs and I'm drawing two branches of your lungs this is let's say going to your this is going to your left lung your left lung and the other branch is going to your right lung so this is your trachea splitting up right and you know that the flu the influenza is going to affect the cells in your respiratory tree so it's going to affect these cells and it's going to cause inflammation you're going to get a big immune response and if that response is really big let's say you have a big response and if it's around these kind of Airways here these bronchioles let me actually extend this out a little bit so you can at least appreciate where the arrow is going if the response is really strong in the bronchioles we call that bronchitis bronchitis so someone might actually develop bronchitis as a result of getting the flu now someone else might actually have a big inflammatory reaction in these little air sacs you know your your lungs end in thousands and thousands of little air sacs and if that happens then you might call that pneumonia you might say well this person has pneumonia finally you have smooth muscle actually lots and lots of it smooth muscle that kind of wraps around the bronchioles and sometimes with the flu you actually can trigger twitchiness of that smooth muscle cysts it starts spasming and when that happens we know that sometimes as an asthma attack so you can actually get an asthma attack related to the flu so all sorts of things like this can happen and it's awful right these are things that can actually land you in the hospital or can cause death as well so these are the kinds of complications and there are other ones things like you know ear infections and sinus infections and many many other things as well but here I just want to show you a few of the complications that people get and show you and remind you that it's usually the high risk people that you have to worry about