TB and HIV | Infectious diseases | NCLEX-RN | Khan Academy



this is Charles prober and this is Morgan theis and now we're going to talk about the interaction between tuberculosis and HIV human immunodeficiency virus and we're going to talk about these because the to actually commonly occur together in different parts of the world and one infection makes the other one typically worse together they create what one might refer to as a perfect storm and so the the stick figures which you've drawn show nine individuals on the top line one of whom is colored in a different color and this is meant to depict the roughly nine million people each year who are infected with tuberculosis one of whom or about 13% is co-infected with HIV so that's a very large portion of the population for which this is a problem it represents over 1 million people the stick figures beneath are meant to depict death caused by tuberculosis and there are three individuals depicted here that represent the roughly one and a half million individuals who die each year from tuberculosis and about one in three of these individuals is co-infected with HIV so the combination of HIV and tuberculosis is incredibly important in very general terms each infection makes the other one worse so in other words if you're infected with tuberculosis and you are or become co-infected with HIV the tuberculosis infection becomes more severe it is more likely to be disseminated it is more likely to be associated with severe necrosis of the lungs or miliary TB or TD men Jada's so HIV makes tuberculosis worse it's almost in every way almost in every way right okay and similarly tuberculosis makes HIV worse through mechanisms that are not clear to me at least have been infected with TB makes the HIV virus proliferate more and makes the progression of the HIV infection more severe so they are mutually bad for each other this is why we call it the perfect storm precisely now clearly ultimately you have to treat both infections because they they are they're both bad infections right so for tuberculosis as we will be talking about the anti tuberculous drugs to use in another video but you do have to use the anti tuberculous drugs and with HIV of course you have to use anti retrovirals in order to control the infection right so it's a given that you have to treat both infections but sort of another part of the perfect storm is that when you begin to treat you may have an adverse effect in something called the immune reconstitution inflammatory syndrome it's abbreviated iris okay I was going to say that's a big word it is a big frame so iris stands for the immune reconstitution inflammatory syndrome and in order to describe the effects of iris I'm going to talk about two hypothetical patients infected with tuberculosis okay immune reconstitution inflammatory syndrome so let's imagine one patient infected with tuberculosis and it's a latent infection it's a quiet infection it's a subclinical infection in those patients when you get infected if you're infected with HIV and you recognize the HIV infection and you begin to treat the HIV infection with antiretrovirals mm-hmm the TB infection they become clinically manifest it is uncovered and that actually is referred to as unmasking iris in other words the treatment of the HIV with antiretrovirals presumably because you reconstitute the immune system makes a TB infection become evident so that's called unmasking iris okay so before you had this latent TB infection you might not have even known you were sick as a patient you get HIV you still don't know you have the TV and then you start treating the HIV and that's when all of a sudden you realize you have TB you get this clinical tuberculosis exact okay so it's unmasked and you recognize it at that point you then treat the TB infection and of course you're in the meantime still treating the HIV infection so that's one hypothetical patient another is a patient known to be infected with tuberculosis they have clinical disease perhaps they have the most common clinical disease which is pulmonary disease then you determine that they also are infected with HIV so you begin again treating the HIV infection with antiretrovirals and paradoxically as you treat the HIV infection the TB infection gets worse and again it's thought that that results from when you treat the HIV infection the immune system becomes more robust because you're controlling the you're controlling HIV infection which was previously camping down the immune system so the immune system becomes more robust and as a result of that robust immune system temporarily the TB infection gets worse that's called paradoxical iris paradoxical iris okay so that makes me think well maybe we just shouldn't treat the HIV and of course that would be not good thinking not because you said it because you must treat the HIV infection because otherwise it will progress and the patient will die of HIV this is a temporary phenomenon where you get transient worsening of the TB infection then as you continue to treat the HIV infection and you continue to treat the TB infection they both eventually settle down ideally okay so this is more something that is interesting and we watch out for it because it can be acutely problematic but that you wouldn't actually change your treatment for you just have to kind of be aware of it and eventually as you treat the HIV treat the TB hopefully things will actually move in the correct direction exactly and then the final thing that I'd like to mention with regards to this perfect storm this badness between having both TB and HIV at the same time is that the drugs used to treat each of those two infections may adversely interact with each other and one that is probably the most important adverse interaction to know about is the effect of refampin a key drug for treating tuberculosis on the different antiretroviral agents specifically rifampin is known to be a inducer of important enzymes in the liver that are responsible for metabolizing a lot of drugs the enzyme system happens to be called the site exciti crome p450 enzyme so rifampin induces that enzyme in other words makes the enzyme more active that enzyme is responsible for enhancing the metabolism of many drugs including anti retrovirals so you end up when you give the refampin causing the anti retrovirals to be metabolized more quickly and looser effectiveness more quickly so you have to be aware of that and other kinds of interactions of drug interactions so that you can modify and modulate your therapy of the infections accordingly and we'll talk about that at another time

9 comments

  1. The two examples show someone with TB getting HIV. I would imagine the more common route would be someone who is HIV+ getting TB. Is there any difference in how these diseases play out in this scenario?

  2. MrGameStarr,

    There is nothing intrinsic to a virus that signifies that it cannot be cured. While viruses tend to be harder to cure for a variety of reasons, a cure is not outside of the realm of possibility.Β 

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