hey everybody dr. o here this video we're gonna cut we're gonna cover the three phases of HIV infection so just real quickly I'll get them out of the way phase 1 either gonna be asymptomatic or if you have any symptoms it would be chronic swollen lymph nodes chronic lymphadenopathy phase 2 is just gonna be this persistent decline in health that happens as your immune system gets weaker and weaker so you're just gonna be no specific infections but it's more likely to get infections this types of things then we'll talk about what are known as constitutional symptoms in this a little bit near the end here and then at phase 3 we'll talk about how when an HIV infection actually leads to AIDS acquired immunodeficiency syndrome and that'll be phase 3 so start here at the beginning so after this primary infection you'll see what's known as acute HIV syndrome so the virus is winning right away you can see the cd4 t-cell population plummets while the viral load gets really high but that and that's because it takes the serial conversion process it takes up to three months to get the antibody the full antibody response to the virus and then once that happens then you'll see the opposite now the viral load is going to drop and the cd4 population is going to go back up first of all because there's less viruses killing them but also your body will make and clone more um cd4 positive T cells so that's why you see so in the beginning if the virus is definitely winning but then after a few weeks up into three months when you see this full antibody response from your immune system now you'll see the cd4 t-cell count climbs back up a bit the viral load drops down quite a bit but then you see this slow steady decline in t-cell population so you may not have any problems if you do just kind of have a weaker immune system than you would expect for someone of your age etc but every day some of these viruses are picking off more and more of your cd4 positive T cells your helper T cells that's why you see this slow steady decline into the years where the cd4 t-cell count is dropping then so that's so so again phase one there really won't be any symptoms if there are any it'll be the chronically swollen lymph nodes because that's where these cd4 positive T cells are being cloned so your body's fighting off the the virus the best that it can during phase two you know what they call here this classic latency you're just seeing for you know for some reason you've just got you've got a weaker immune system then you should have and then we're reaching a point where near the end of that you're gonna start to see what are known as constitutional symptoms that's going to be things that can affect the entire body fever night sweats chills weight loss these types of things and then we get into the territory where you now have AIDS and it's very very important to know when this happens so an HIV infection leads to AIDS when your cd4 positive T cell count drops below 200 that you can see on the chart so once that numbers under 200 or under what's you know 14 percent of normal so the two hundreds the most important number there but it's also that's another way to look at it so once you reach a cd4 t-cell count of 200 or below you now have AIDS and that's where as you can see on the right-hand side of the chart the opportunistic diseases are going to show up so I have a list of some of them I'll show you in just a moment but these would be diseases that shouldn't impact someone with a normal immune system or at least not the same way let's go and look at a few of those and then we'll come back and see the end of this so just I'm gonna just pick out a few of them here like Toxoplasma gondii eyes so this is only immunocompromised people should have a problem with this there are many people that have been infected with this organism but your immune system walls it off and doesn't cause any problems but if you're immunocompromised it can lead to encephalitis the inflammation swelling in the brain sattell megalo virus so most humans have been exposed to it it usually causes no problems or maybe a mild fever for a few hours but if you don't have a strong immune system as you can see here fever and settle itis blindness you know even death those would be good examples tuberculosis with Mycobacterium tuberculosis obviously you know many many people are infected with that that have normal you know normal immune systems but if you have in HIV or AIDS it appears it appears to be worse and also this is where we think some of the drug-resistant strains of tuberculosis are basically incubating in AIDS patients so hard to say for sure but I've seen that from multiple sources just a few more here we talked we talked about Pneumocystis a little bit in the history of HIV video yeast infections can become a problem Kaposi's sarcoma is one of the ones you hear the most often with AIDS patients so it's actually a cancer of the skin and the blood vessels so these are all these are all common examples let me just jump back to that first image so those are the examples of the opportunistic diseases that are that are attacking an AIDS patient because they're immunocompromised they don't have a strong immune system and then filing the death so what what kills an AIDS patient isn't AIDS it's the fact that their immune system is gone so I remember you know when I was a kid there was someone named Pedro on one of the real world shows on MTV and he at the end of that show his t-cell count was zero like so you said the virus can completely eradicate your helper t-cell population and they're needed for to mount a t-cell or cellular immunity response and your b-cell antibody mediated response so so any infectious agent even even pathogens or organisms that aren't normally pathogens can kill someone without an immune system so that's what leads to the death there at the end one last thing I want to cover here would be diagnosis because you're seeing the antibodies and the viral load here on this image so the first test the the the test that most people would do first would be the ELISA test to look for HIV antibodies but like I mentioned earlier that can take up to a few months let's say you're working in a health care environment get a needle stick injury like you're gonna be tested but you're they're also gonna want to test you again in a few months and then a confirmatory test so the antibody test is a good place to start but a confirmatory test would be either the Western blot or what's now called the AB tema which is an RNA test but because HIV is an RNA virus that's looking for the actual virus so to me that the first test you would do would be to look for the antibodies with the ELISA then you would confirm by actually looking for the virus okay all right so those are the phases of HIV infection as well as some some just basics about how to diagnose the disease I hope this helps have a wonderful day be blessed