DIP Episode 3 - Viral Cases B

Welcome. My name is Divine, my fourth year medical student. Welcome to a third episode. And today we're going to be talking some more about those viral cases. Just as a refresher, we had an episode two where we said a lot about like the like the big super super high-yield viruses that have a lot of details with them. The viruses I'm going to discuss today they have like very few details but those details are very well tested. So slide one says viruses that destroy anterior horn cells right so for your exam you sort of want to think about two viruses here. The first one is the polio virus and the second one is the West Nile virus. The West Nile virus is less commonly tested but the polio virus is certainly tested. Okay and the polio virus is in fact the positive stranded RNA virus. Okay it's a big corner virus so pickle means small right. Pickornah there's an RNA after pickle so it tells you it's an RNA virus okay and then it's a virus okay so that's just a nice memory tool there. No the polio virus and all the big corner viruses they actually describe those being in teroviruses. Okay excuse me. Oops sorry so they're described as in teroviruses and don't let that deceive you. These bugs don't actually cause gastroenteritis okay so just something to keep at the back of your mind but a lot of these bugs cause something called an eceptic meningitis so basically a meningitis that is from non-bacterial infection if you may.

So the polio virus okay people get it through the fickle or route okay and the thing it does is it basically infects the anterior horn of the spinal cord you could also call that the ventral horn remember those are where the alpha moron neurons that go to the neuromuscular junction are begin okay remember those neurons receive inner vision from the fibers of the cortical spinal tract okay so it infects the ventral horn of the spinal cord just like a wisno virus does okay and this will present with a flasid paralysis okay and the classic patient here is a patient that has not gotten immunized okay or like an immigrant or something like that okay so flasid paralysis although you generally have no sensory problems okay no sensory problem and this like I said is vaccine preventable you can give the live vaccine it's a seaband vaccine that's no longer used in the US you could alternatively give the salt vaccine which is the killed vaccine that's the one that's used in the US because the risk of having a reactivation of polio if you give the seaband vaccine is much higher than the risk of getting polio in the US okay because polio has largely been eradicated in this country now so yeah that's like one so let's go to slide two so the koksaki toxic drums so I mean like if you read the review books you hear a ton of stuff about koksaki viruses but really they're like two big things you need to know okay the first thing you want to know is obviously the apricorn viruses so they're small but you want to know more about koksaki and B okay now koksaki A is the thing that causes a handful of mouth disease okay so it causes like you can get like a rash on your hands and on your feet okay and it actually causes a hip angina so you describe a person that has like lesions on the bachoma eucosa that is sort of whitish in the middle and have a very theme around them think about hip angin

a especially in a child okay and the way you prevent this is primarily with good hand washing every now and then you meet the off-putting mbm question that asks about oh how would you prevent infection with blah blah blah blah okay this is one way if you wash your hands you won't get into trouble another high-yield one is the C-deficile infection okay you can prevent C-deficile by washing your hands regularly and just as a pro tip when you get into the hospital after you see every patient just go ahead and wash your hands just for your own safety and the safety of your other patients okay now the koksaki B virus causes myocarditis in fact it's probably the most common cause of like a viral myocarditis so basically they describe a person like a young person that doesn't really have any like heart failure risk factors like oh they don't smoke or they don't have really bad hypertension and all that stuff and then they present with like a relatively like rapid onset like shortness of breath and the hypotensive and they tell you that all the ejection fraction is down and they say that oh this person had like an upper respiratory infection a few days to weeks ago you really want to think about viral myocarditis from koksaki b not koksaki a koksaki b virus okay and the differential diagnosis of veration the pumps and sozes actually high you to know for step one as you're studying for your test you'll probably learn this nomonic that you drive a kalsaki cars with your hands and feet okay to remind you of the koksaki a virus so that's koksaki a for the CA and then the R stands for ketzier ketzai okay remember that's Rocky Mountain spotted fever um and then the S stands for secondary syphilis okay and then another kalsakis kalsakis disease remembering kalsakis disease that is the only time you should potentially on an mbmi every give aspirin to a little kid okay remember the ri

sk of right syndrome with that now the next light talks about causes of the common code so the common code is classically caused by viruses okay and the big ones you sort of want to know are your coronaviruses and your rhinoviruses okay in fact your rhinoviruses is the most common cause of the common code okay um you can never get uh like permanent immunity against the rhinoviruses because they're like there's I think like hundreds of zero types or something ridiculous okay so fortunately you probably get it from year to year for something like that well I guess if you're careful you wouldn't get it okay now the coronaviruses and the rhinoviruses just protect its a positive stranded uh stranded RNA virus okay contrast that with the coronaviruses that is a negative stranded RNA virus okay and the SARS virus remember like the avian flu bird flu and all that fun stuff uh uh is easy in fact caused by the SARS virus which is a coronaviruses derivative and that is spread through respiratory droplets so if they describe if they give you like some kind of association with like China or some parts of Canada and um you see like very severe common code symptoms and stuff like that maybe think about coronaviruses and the SARS virus another question we they could pose it on exams is as like a terrorist attack for example where they say oh someone received something in the mail or like we're weaponized virus or stuff like that okay now um so yeah let's jump onto the next slide we're going pretty quickly today that's good now recent return from a trip to South America ASD and ALT in the thousands this patient consumed lots of foods on his trip and now presents with scleralectors so first things first I'm not putting this question here to discourage you from eating when you go on foreign trips uh just you know use common sense not just going elsewhere like even in the US as well uh j

ust use common sense when you're eating certain things right so you don't get yourself into trouble but I'm really hoping you're thinking of some kind of hepatitis viral infection okay uh more likely hep A okay so uh one reason I wrote this question like this it's kind of nondescript is to sort of get you thinking of you know uh if information is not there okay don't assume it to be true to make an answer sound good to you okay um so for example I didn't say anything about like sexual contact or blood transfusion or whatever so you probably should have hep B and C very low your differential here and you also probably should not think about hep E because I didn't say anything about a pregnant woman in this question okay so this is the hep A virus okay uh you get this through a fickle oral spread okay so to think of it this way your hepatitis alphabet goes from E through E right so like ABCDE okay and remember like your mouth and your A-ness if you may add the two orifices of like I guess big orifices of your GI tract so fickle oral right so that helps you remember that hep A and hep E are both acquired through the fickle oral route okay and there is in fact a vaccine against hep A okay um there's no chronic for for hep A right thankfully and again think of chryptophoryne country like food or contaminated water exposure for hep A and the USDAL Ts can be super super elevated they can be in the thousands okay and that's pretty much all you need to know about hep A but just remember that it's definitely a something that can be um can be treated I mean sorry it can be prevented by vaccines and one of the thing I will say is but this is more for like a pediatric shelf exam is that there is an association with D-Cure so there are people that actually get the hep A infection from D-Cure's okay because remember D-Cure is not always the most uh let's call it sanitation friendly p

lace in the world and I mean that's for obvious reasons right okay so next slide so quick overview of the flavy viruses right so here um just again a few things you need to know about each of these viruses we'll talk about the dengue virus and yellow fever virus okay and basically the way they would describe the dengue fever okay they call it like the uh brick bone fever hurts a lot okay and basically the thing that happens the way to present on your exam is as a person that has a super super high fever and they have like out of this world muscle and joint pain okay if you see that uh think about um think about the dengue virus it's a flavy virus okay and the special thing about these flavy viruses is they are largely transmitted by um arbor viruses the only so that's like a atropod borna their atropod borna infections the only notable exception here is hep C hep C is a flavy virus but it kind of does its uh its own thing so probably talk about that in a later episode okay so dengue brick bone fever that's the big thing you want to remember now yellow fever um it's kind of low yield but it's one of those unusual things that I'd imagine that if people saw in like large quantity on the exam a lot of people will get it wrong so don't be one of those people uh because you listen to this podcast uh basically the yellow fever virus okay um I mean it's called yellow because you literally look yellow when you get it okay so you get a jaundice in fact a very specific finding on exams is if they describe a person that has black vomit uh if you see like black vomit um a person that has like risk factors for exposure to some kind of mosquito like the atis mosquito for example and the person has like black vomit they have jaundice think about a yellow fever in fact um just while we're still on the topic of the atis mosquito I really want you to remember the zika virus the zika vir

us is actually carried by the atis mosquito as well okay uh but you on exams they'll probably present zika in the context of like sexual transmission or like vertical transmission from mom to baby okay and uh basically if they describe a kid that's born with um microcephaly okay and they put like a South American association or something or something or something that just came back from South America and they delivered a baby with like a very small head uh really think about zika virus okay think about zika virus now back to yellow fever although we're things to know about yellow fever there's actually a pretty nice way they can integrate this with uh GI okay one way they can integrate this is to ask like where would yellow fever infect in the liver okay because I mean it causes uh jaundice right so this should sort of tell you that maybe this bug kind of messes with my with the person's liver in a summary shape or form so the thing is if you remember back from whatever learning you've done or the learning you would do during your dedicated period you've probably heard of the different zones of the liver right so you've heard of like zone one which is the area around the portal triads right remember the portal triads are like your uh your uh your portal vein your hepatic area your bowel duct okay that's the periportal region of the liver that's zone one okay uh that's the region that's classically torched by viral hepatitis okay and then you move on to zone two zone two is sort of like in the middle before you get uh plus enough to the central veins okay zone two is the intermediate zone okay and that's the region that's classically torched by yellow fever okay very high to know that for your exam and one classic histologic finding in zone two is like the consulman body okay it's just basically like a dead hepato site they look very pink okay so like if you see like

oh they describe like like uh uh you see nophilic infiltrate if you mean the liver think about yellow fever uh the yellow fever virus okay and then just as an aside remember there's zone three okay it's also called the central lobular zone okay or the peri central zone of the liver okay so it's right around the central vein okay um this region um is susceptible to ischemic change and that should sort of make sense because it's for this from the blood flow through the liver okay so it's just like the met students right here at the bottom of the totem pole in the hospital so you get the you get the short end of the stick on uh short i guess long end i don't know what end whatever end that floats you about okay well you get the short end of the stick this one i'll choose for this episode um because you're like last on the totem pole right so same thing the region around the central vein most susceptible to ischemia and this region also has a tonne of cytochrome p450 um enzymes okay so metabolic toxins tend to affect this region uh pretty easily as well okay so remember peri central zone ischemia uh metabolic toxins tons of cytochrome p450s okay and uh alcoholic hepatitis alcohol also prefers to nuke this area of the liver again remember that boost is broken down in some pathways by cytochrome p450 enzymes okay so next slide so rebella versus rubiola showdown oh this sounds enticing so let's talk about these box okay so first thing you need to get down with these bugs uh the autogoviruses okay and you need to get these uh uh uh uh uh uh actually sorry rebella is the toga virus rebella is the toga virus but one thing i want to say here is you want to make sure you get the terminology down for these okay rebella is known as german measles okay measles is known as rubiola okay so rebella is also known as german measles rubiola is also known as measles right now it's kind of

annoying but it's just one of those things you want to set up put down your mind somewhere okay and the way you get rebella so let's talk about rebella first and then we'll talk about uh rubiola okay although i'll mention some side by side comparisons okay so rebella you get it through the respiratory tract okay um and basically if you get a question about a kid that presents with a rash that starts on the forehead okay and goes down okay and sort of think of it as a less toxic presentation if you may think about rebella okay but for rebella a sort of subtle difference here is that this person will have a rash below the ear or you can say like behind the ears okay or the neck and then it goes down right so it doesn't start on the forehead like we have with rebella okay and also with rebella if i'm remembering correctly i believe you also get posterior or ricola lymphatic synopathy if you see that association think more rebella than rebella okay and you tend to get a much more toxic presentation with rebella infection okay so um so back to rebella rebella rebella starts on the forehead goes down um remember congenitor rebella syndrome okay so if a kid is born with a panoract okay and they have like deafness and uh classically they will put in uh pitten doctors arteriosus remember your machine-like murmur on a scotation okay also the kid is usually born with microcephaly uh think about um think about uh um the rebella virus okay and just real quick because i didn't say back then yellow fever is actually vaccine preventable okay so back to rebella okay so uh remember rebella is in fact vaccine preventable you can get the mmr vaccine so it's a live vaccine with a vaccine okay so you want to avoid it in like a woman that's pregnant or a kid that's less than a year old or a person that is severely immunocompromised right so they give you a person that has a cd 4 count and th

ey have HIV and the cd 4 count is like 50 probably the one to give them the mmr vaccine okay you may actually be giving them something that would actually go ahead and kill them okay now to talk about rebella so we've said that uh rebella um it's you tend to get a more toxic presentation problem starts behind the ears and sort of goes down um and remember your three C's right guess you can call them three C's and it came for rebella which is measles okay uh you give the cough the chorizo and conjunctivitis chorizides means run emails okay and then the case stands for a couple of spots okay so basically they're like erythematos white-tish spots on the bachomeucosa um that's a classic exam presentation of uh measles or rebella okay now if they describe a person that has a history of measles okay like a kid let's say they had like a measles infection whatever when they were little and then like 10 years down the line or 15 years down the line they begin to have like these rapidly progressive neurologic deficits they're not doing well in school uh they begin to kind of act weird think about something known as the subacute sclerosin uh panacephalitis okay SSPE um it's almost always a hundred percent fetal um and again it's just something you sort of want to keep uh want to keep in mind okay that's something that I've seen tested quite often now remember that uh rubula or measles is vaccine preventable okay and I say that for rebella that oh you a kid could be born with a cataracts with that um one of the thing I just sort of want you to consider when you think about a cataracts in kids um think about galactosemia okay galactosemia remember it's a deficiency of a galactose one phosphideorodiotransferase okay so they describe a kid with like liver symptoms and cataracts you want to think about some kind of galactose metabolic disorder okay now next slide uh barky seal like co

ugh with a chest x-ray revealing the steeple sign right so this is the pyrin influenza virus this is group um remember this is a subglotic um infection okay and it will classically present with um strider okay because it's an upper respiratory tract infection okay and uh I'll encourage you to look up videos of the barky seal like cough it's actually a pretty striking uh when you see that okay and it's something you probably see on your pediatric certification as well so that's all I'm gonna say about uh pyrin influenza now question eight uh slight eight says a peace core worker who just returned from Liberia is bleeding from every arithas he spent some time playing with monkeys and eating some local meats okay so with this I'm really hoping you're thinking of uh the Bola virus okay the Bola virus uh so this is a phylo virus okay it's an envelope virus it's also he has a hella co-shape um and basically the reason you get a hem like a lot of like bleeding with Ebola is that um the virus expresses something that's sort of like nukes endothelial cells like cells that line the vasculine dothelium so if you're nuking those endothelial cells um you begin to bleed from like everywhere right because remember most of our blood vessels are lined or but they say all of our blood vessels are lying by endothelial cells um and the way you can get this is if you're getting contact with blood from an infected person um or if you have exposure to like monkeys right so monkeys carry this uh uh this virus okay and in fact if they describe like a person that went on T-score or some kind of volunteer whatever thing to like Liberia for example okay that's the classic association you sort of want to keep in mind okay and one nice way that step one can test this virus is to talk about how you can prevent spread right so you'll want to explore some kind of barrier protection okay and you also

want to very strictly isolate the patients okay because this is something that is very fatal if you contract it there's very few people that have survived uh survive this okay and it's a reportable illness okay so it's one of those reasons why you could break our patient confidentiality again that's another very nice way you can introduce ethics with Ebola virus on your exam okay so you have a duty to warn uh to warn other people now next slide uh does he influence or cause the flu no okay uh just don't make that mistake for your exam uh so what actually causes the flu the thing that causes the flu is the influence of virus okay the influence of virus I remember the influence of virus at ortho mix of viruses okay and there is influenza a and influenza b okay I influence that a infect both humans and animals influenza b just humans okay and some quick pathophysiology here these bugs they have something known as uh I'll say like there are two big proteins you want to know one is hemoglobin and two is neuromini days in fact you use this HN uh uh convention to I guess serotype these bugs okay and hemoglobin basically what it does is it binds to psialic acid okay and once it binds to psialic acid that will find on the surface of cells it enables the virus to get into a cell okay uh and when the virus gets into a cell usually goes into lysosomes okay and he uses the acidic environment of the lysosome to sort of take off its jacket okay so it's just sort of think of it as going to a restaurant in the winter and having like a coat rack where you like drop your coat okay so it takes off its jacket and it uses the acidic pH of the lysosome to make that happen okay um and that that acidic pH is created by a proton pump uh it's called like the M2 proton pump if you may okay so inhibiting that M2 proton pump inhibits uh uh on coating of the virus that's how drugs like a mantidine

and a remantidine work or although no one uses that in India okay and I'll talk about why in a bit okay now after the virus has done all its fancy stuff in a human being and wants to go and spread to a new cell uh it uses neuromini days to cleave the hemoglobin from the salic acid and then continues its journey to some other unfortunate cell it so happens that neuromini days is inhibited by drugs like oseltami vian zanami vian okay they cover both influenza a and b okay and um uh that's how those drugs work but you have to give them within like the first 48 hours of infection to get any kind of effect okay and the thing is uh you get inflate uh I mean a mantidine remantidine there isn't I say they are no longer used is there's like a hundred percent resistance so a mantidine it was actually discovered that it has some pro-dopamine ergic properties so it's actually used right now in the treatment of Parkinson's disease and again you get the flu from exposure to respiratory droplets okay and one special thing I will say about the flu so going again into some more pathophysiology is that the influenza virus has a segmented genome and having that segmented genome creates lots of problems okay the lots of problems I'm gonna talk about involve antigenic drift and antigenic shift okay now sort of think of something drift in a way that's milder than something shift in a way okay um for the antigenic drift the thing is the RNA polymerase that works on the influenza virus is very error prone it's not very good at proof reading okay so because it's not very good at that you can create all these mutations in hemoglobin and uremini days that makes uh uh somewhat modified virus okay and when you have this you get something known as an epidemic okay but contrast this with an antigenic shift where basically you just assume like two influenza strangers the effect the same cell like a

animal cell for example and then you basically smash different segments of the segmental genomes of the toolbox together and then you create a brand new trick-thoud virus that no one has ever seen this is what causes a pandemic okay this is what causes a pandemic so make sure you can differentiate between an antigenic drift and an antigenic shift and what causes both okay and if they describe a person uh and again the way the influenza virus presents on exempts is uh like a person that has like myodias headache cough runny nose all that fun stuff I guess not fun for the patient um so if you see that and if you see like especially like a good time period like December January or whatever on an exam think about the influenza virus okay and if they describe a person that is like recovering from the flu okay and boom they have like very high fevers they have like a cavitory lesion and a chest x-ray and they get super sick get almost septic think about a secondary bacterial infection from staff orius okay from staff orius you definitely want to think about that okay and um again if they describe a kid that had the flu and then now they present with like hypoch like simian like neurologic problems like the acometals think about right syndrome okay because the kid got aspirin now um the flu virus can also uh getting like an infection of the flu virus can also ultimately lead to Guillembury syndrome okay so don't just think only of Campylobacteria okay now because I love to integrate stuff together uh one of the things that they could actually test in relation to the flu virus is um it's sort of like a bio stats concept right so uh let's assume you'll get to the fall right so like this November December whatever and you're told that like oh the flu detection whatever test they ask oh like what happens to the sensitivity and specificity during the spirit of the year those do n

ot change okay those are fixed properties of a test however the thing that would increase is the positive predictive value okay because think about it if a person came in like June and said oh divine I have the flu like whatever no I mean I won't say that you know I'll be more patient centered and empathic but I mean empathetic but if a person came and said like uh divine I have the flu let me cough on you like in December I say like oh no I know you have the flu right because if I got a result from the flu detection test then I'm more likely to believe it than in June okay so the PPV the positive predictive value has increased because the prevalence of the flu increases uh in the fall so just something to sort of keep in mind and again this is uh there's vaccines for this uh most people get the injectable vaccine um the live-attenin with it vaccine is the intranisal vaccine and again kids less than a year old people that are severely immunocompromised or pregnant women should probably not be getting this okay now um the last part of this slide has an aside it doesn't fit well elsewhere uh what would your diagnosis be for patient presented with severe leg myalches and respiratory difficulty from pulmonary edema with a history of exposure to rodent poop uh this is the hunter virus okay it's a bonia virus uh these people tend to have like myalches more specifically in the legs okay and they have a lot of pulmonary symptoms because they get a lot of pulmonary edema with this virus so the last slide what are you diary in an infant so what is this um hoping you're seeing some kind of reo virus right some kind of negative stranded RNA virus maybe right so root of virus okay so root of virus remember it's a double stranded RNA virus very high you to know that factoid and it classically causes watery diary in infants okay so on your exam if they describe an adult like some of

this like 25 right and they have diarrhea you probably should not be picking root of virus as the inciting agent right because again that is i've never seen it tested in that context well i guess until the mbme does now um so the root of virus classically causes a watery diary in infants it is in fact vaccine preventable okay although one unusual bizarre concept deco-test on the step one is avoiding this in a kit with a history of interception okay remember you interception with uh coronjelly stools okay and just real quick while we're on the subject of coronjelly uh what are you thinking about in like an alcoholic that has like a coronjelly spudum well i hope you're thinking of clipsyllum pneumonia okay uh clipsyllum pneumonia remember it's a urese positive box okay so that is all i've got today in the third episode of a divine intervention okay uh the next time we meet we'll probably talk about some other topic or just finish up this viral atriloge okay uh but i hope you find this useful if you spot any errors or you have any questions or any feedback uh please feel free to reach out um the email is a divine intervention podcast at gmail.com have a wonderful day and um i'll see you in the next episode bye

It infects the anterior horn cells (ventral horn) of the spinal cord, leading to flaccid paralysis.

Coxsackie B virus.

Cough, Coryza (runny nose), and Conjunctivitis.

The presence of Councilman bodies, typically found in Zone 2.

Pandemics are caused by Antigenic Shift (mixing segments from different viruses), while epidemics are caused by Antigenic Drift (minor mutations).

Both are transmitted via the fecal-oral route, but HAV is associated with contaminated water/food, and HEV can be seen in immunocompromised individuals.

Yellow Fever virus.

Subacute Sclerosing Panencephalitis (SSPE).

Dengue (breakbone fever/severe joint pain) and Yellow Fever (black vomit/jaundice).

It inhibits Neuraminidase, preventing the virus from cleaving sialic acid and spreading to new cells.

Zone 2 (the intermediate zone).

Yellow Fever virus.

Subacute Sclerosing Panencephalitis (SSPE).

Dengue (breakbone fever/severe joint pain) and Yellow Fever (black vomit/jaundice).

It inhibits Neuraminidase, preventing the virus from cleaving sialic acid and spreading to new cells.

Zone 2 (the intermediate zone).