WEBVTT 1 00:00:08.033 --> 00:00:10.666 Hello, my name is Kubi. 2 00:00:10.666 --> 00:00:13.466 I'm a clinical chemistry fellow at the University 3 00:00:13.466 --> 00:00:17.750 of Utah Department of Pathology and at IRP laboratories. 4 00:00:18.016 --> 00:00:21.716 Today, I'm going to talk to you about HIV diagnosis. 5 00:00:24.050 --> 00:00:26.550 So here are the objectives for the talk today. 6 00:00:26.550 --> 00:00:30.383 We want to understand and distinguish between HIV and Aids. 7 00:00:30.650 --> 00:00:35.116 We also want to describe the pathophysiology of HIV infection 8 00:00:35.366 --> 00:00:37.466 and the disease progression. 9 00:00:37.466 --> 00:00:40.800 Finally we want to discuss screening and diagnostic 10 00:00:40.800 --> 00:00:43.800 tests for HIV. 11 00:00:43.966 --> 00:00:46.200 So before we get into the presentation 12 00:00:46.200 --> 00:00:49.200 I'll talk I'll go through this case study. 13 00:00:49.400 --> 00:00:52.616 And as we go through the presentation have this in mind. 14 00:00:52.616 --> 00:00:54.500 We'll get back to this case study. 15 00:00:54.500 --> 00:00:58.583 And based on the information that we get from this presentation, 16 00:00:58.816 --> 00:01:03.466 we'll try and go through laboratory testing for this patient. 17 00:01:03.900 --> 00:01:06.900 So we have a 30 year old female patient 18 00:01:07.100 --> 00:01:12.266 that has been well until approximately six days earlier when she began to have 19 00:01:12.266 --> 00:01:17.933 a vaginal discharge followed by headache, fatigue, sore throat and anorexia. 20 00:01:18.383 --> 00:01:23.033 On the fifth day of symptoms, she went to an outpatient clinic in an urban area. 21 00:01:23.416 --> 00:01:26.416 On examination, she had a vaginal discharge 22 00:01:26.600 --> 00:01:30.083 and temperature and the remainder of the examination 23 00:01:30.683 --> 00:01:33.116 were reportedly normal. 24 00:01:33.116 --> 00:01:35.783 Patient has had multiple sexual partners 25 00:01:35.783 --> 00:01:39.916 and hasn't always used protection, that is, condoms for intercourse. 26 00:01:40.550 --> 00:01:42.616 Patient has a history of STDs. 27 00:01:42.616 --> 00:01:46.283 Gonorrhea, syphilis that has previously been treated 28 00:01:46.650 --> 00:01:49.916 lab screened for gonorrhea and syphilis as negative. 29 00:01:52.366 --> 00:01:53.366 So keep that 30 00:01:53.366 --> 00:01:56.366 in mind as we go through this presentation. 31 00:01:56.416 --> 00:01:59.550 So first we start by looking at what HIV is. 32 00:01:59.716 --> 00:02:04.666 So HIV as an acronym for human immunodeficiency virus. 33 00:02:05.216 --> 00:02:09.683 And this belongs to a family of viruses that are called retroviruses. 34 00:02:09.900 --> 00:02:14.666 So retroviruses are viruses that are able to insert 35 00:02:14.700 --> 00:02:18.616 the nucleic acid material into the host genome. 36 00:02:19.366 --> 00:02:23.700 And these viruses have a number of subfamilies. 37 00:02:23.700 --> 00:02:27.983 And importantly, HIV belongs to the author. 38 00:02:27.983 --> 00:02:29.900 Retro. Very. 39 00:02:29.900 --> 00:02:33.966 And this is a reverse transcriptase dependent virus. 40 00:02:34.016 --> 00:02:36.900 And what are reverse transcriptase enzyme. 41 00:02:36.900 --> 00:02:40.066 So the reverse transcriptase is an enzyme 42 00:02:40.400 --> 00:02:44.416 that helps to convert RNA into DNA. 43 00:02:44.716 --> 00:02:48.416 So in molecular biology we have the central dogma where we know 44 00:02:48.416 --> 00:02:51.416 that DNA is converted to RNA 45 00:02:51.416 --> 00:02:54.533 and then RNA is translated into proteins. 46 00:02:54.900 --> 00:02:59.716 In this case we have RNA that is going to be transcribed 47 00:02:59.716 --> 00:03:04.016 into DNA by the help of the reverse transcriptase enzyme. 48 00:03:04.550 --> 00:03:09.766 And the HIV also belongs to the genus lenta viruses. 49 00:03:10.166 --> 00:03:12.383 And these are slow growing viruses. 50 00:03:12.383 --> 00:03:17.100 And as we can see on here, that is what we have highlighted there. 51 00:03:17.333 --> 00:03:23.483 And so the lenta viruses consist of the HIV one and two which we'll look at. 52 00:03:23.850 --> 00:03:29.483 It also has the five which is the feline immunodeficiency virus. 53 00:03:29.483 --> 00:03:32.750 And then there's E IAV which stands 54 00:03:32.750 --> 00:03:35.750 for equine infectious anemia virus. 55 00:03:36.083 --> 00:03:40.966 And it's important to note that these viruses all do not have a cure. 56 00:03:41.300 --> 00:03:44.100 There can be therapy in the case of HIV, as we'll 57 00:03:44.100 --> 00:03:47.100 look at as we go through this presentation. 58 00:03:47.300 --> 00:03:50.783 And it's important to note that the HIV 59 00:03:51.500 --> 00:03:54.883 virus is transmitted via exchange of bodily fluids. 60 00:03:54.900 --> 00:03:56.566 And so this can be blood. 61 00:03:56.566 --> 00:03:58.316 It can be via breast milk. 62 00:03:58.316 --> 00:04:02.850 You can have seminal and vaginal secretions as well. 63 00:04:07.100 --> 00:04:10.700 So now let's look at HIV and Aids. 64 00:04:11.216 --> 00:04:13.766 So like I mentioned 65 00:04:13.766 --> 00:04:17.033 there is this treatment available for HIV. 66 00:04:17.333 --> 00:04:20.333 However there is no cure for HIV. 67 00:04:20.416 --> 00:04:23.416 And looking at the image above, 68 00:04:23.483 --> 00:04:25.883 after HIV infection, what happens 69 00:04:25.883 --> 00:04:30.050 is the HIV attacks the humans T cells 70 00:04:30.416 --> 00:04:33.116 and the HIV then hijacks the T 71 00:04:33.116 --> 00:04:36.566 cells and produces more copies of itself. 72 00:04:36.916 --> 00:04:41.250 And in doing this, it leads to the destruction of the T cells. 73 00:04:41.416 --> 00:04:47.250 And so progressively patients are going to have depleted T cells. 74 00:04:47.483 --> 00:04:51.000 And that is going to lead to this immunodeficiency. 75 00:04:51.300 --> 00:04:55.616 And so Aids stands for acquired immunodeficiency syndrome. 76 00:04:56.866 --> 00:05:00.233 And so what actually happens when a patient has Aids. 77 00:05:00.500 --> 00:05:04.216 Like I mentioned the T cells count reduce. 78 00:05:04.216 --> 00:05:06.950 And so there is immunodeficiency. 79 00:05:06.950 --> 00:05:12.383 And so what happens is there's a lot of opportunities opportunistic infections. 80 00:05:12.766 --> 00:05:16.200 And so these can include TB candidiasis 81 00:05:16.433 --> 00:05:21.466 and other infections that would otherwise not affect a healthy individual. 82 00:05:21.766 --> 00:05:25.816 There can be cancers like Kaposi's sarcoma amongst others. 83 00:05:26.100 --> 00:05:28.733 And then there can be Whiston syndrome. 84 00:05:28.733 --> 00:05:32.866 And so that is responsible for that emaciated look that we see 85 00:05:32.866 --> 00:05:34.016 in HIV patients. 86 00:05:34.016 --> 00:05:39.466 And so this just shows an image of a patient with with Aids. 87 00:05:41.033 --> 00:05:44.033 So now we move on to the HIV types. 88 00:05:44.216 --> 00:05:47.933 So the HIV has type one and then type two. 89 00:05:48.466 --> 00:05:52.250 And with the type one it has a more global distribution. 90 00:05:52.666 --> 00:05:57.500 As we look at the type two we see that it is more predominant in West Africa. 91 00:05:58.050 --> 00:06:00.500 Again the type one has passed for faster 92 00:06:00.500 --> 00:06:03.983 progression from infection to the Aids stage. 93 00:06:04.283 --> 00:06:07.516 And then the type two has slower progression. 94 00:06:08.066 --> 00:06:10.950 And then when we look at the plasma viral loads, 95 00:06:10.950 --> 00:06:15.150 the type one has higher plasma viral loads than the type two. 96 00:06:15.350 --> 00:06:18.500 And this is because the type one replicates faster 97 00:06:18.500 --> 00:06:21.500 than the HIV type two. 98 00:06:22.316 --> 00:06:24.166 And in terms of the origin, 99 00:06:24.166 --> 00:06:28.950 it's been shown that the HIV type one has origins from chimpanzees. 100 00:06:29.333 --> 00:06:34.700 And then the HIV type two has origins from the manga base. 101 00:06:36.983 --> 00:06:37.700 Now we move 102 00:06:37.700 --> 00:06:41.150 on and look at the epidemiology of HIV. 103 00:06:41.633 --> 00:06:44.783 So like we mentioned we've seen that there's HIV type 104 00:06:44.783 --> 00:06:47.783 one and then there's HIV type two. 105 00:06:47.966 --> 00:06:50.966 And so zooming in to the HIV type one 106 00:06:51.616 --> 00:06:55.433 we see here that there are various groups under the HIV type 107 00:06:55.433 --> 00:07:00.716 one there's group M group and group O and group and group M 108 00:07:00.716 --> 00:07:05.750 as the group that is responsible for most of the cases that we see. 109 00:07:06.083 --> 00:07:10.200 The group N or NP are predominantly found 110 00:07:10.316 --> 00:07:14.600 in West Africa and some have been found in just a few patients. 111 00:07:14.850 --> 00:07:18.166 And so when we look at the group M of particular 112 00:07:18.166 --> 00:07:21.350 importance is the subtype B. 113 00:07:21.683 --> 00:07:24.383 So the subtype B is the more predominant 114 00:07:24.383 --> 00:07:27.566 subtype that we see here in the Americas. 115 00:07:27.800 --> 00:07:32.633 And so we have other subtypes that you find in other parts of the world. 116 00:07:34.850 --> 00:07:36.150 So here we see a 117 00:07:36.150 --> 00:07:39.766 global distribution of the HIV type one. 118 00:07:40.100 --> 00:07:43.700 And so as the chart indicates like I mentioned before, 119 00:07:44.100 --> 00:07:49.316 the subtype B as the subtype that you see mostly in the Americas 120 00:07:49.550 --> 00:07:52.850 and other parts of the world will see different subtypes. 121 00:07:53.183 --> 00:07:56.300 And over here we see some recombinant types 122 00:07:56.483 --> 00:07:59.483 that are found in other parts of the world. 123 00:08:01.133 --> 00:08:02.600 And here we take a look 124 00:08:02.600 --> 00:08:06.416 at the global statistics on HIV. 125 00:08:06.833 --> 00:08:10.066 So these are statistics from the year 2020. 126 00:08:10.433 --> 00:08:13.316 And so here we see that there are about 127 00:08:13.316 --> 00:08:17.033 39 million individuals that are living with HIV. 128 00:08:17.516 --> 00:08:21.383 And of these about 37.5 million adults. 129 00:08:21.416 --> 00:08:26.300 And we have about 1.5 million children under the age of 15 years 130 00:08:26.666 --> 00:08:29.366 that are living with HIV. 131 00:08:29.366 --> 00:08:32.366 And in terms of people that are acquiring 132 00:08:32.533 --> 00:08:38.066 for the year 2020, about 1.3 million individuals acquired HIV. 133 00:08:38.366 --> 00:08:40.366 And here are the distributions. 134 00:08:40.366 --> 00:08:43.733 And so here there's about 1.2 million adults. 135 00:08:44.100 --> 00:08:46.433 And when we look at the gender distribution, 136 00:08:46.433 --> 00:08:52.200 we have a higher proportion of males having having new infections. 137 00:08:52.516 --> 00:08:56.566 And then in children we have about 230,000. 138 00:08:57.150 --> 00:09:01.250 And then here we look at deaths from HIV related causes. 139 00:09:01.516 --> 00:09:08.533 And so in 2022 there were about a 630,000 deaths from HIV. 140 00:09:08.533 --> 00:09:10.733 And the distribution is as shown here. 141 00:09:10.733 --> 00:09:13.783 So we have about 540,000 from adults. 142 00:09:14.100 --> 00:09:17.966 And then we have about 84,000 from children. 143 00:09:20.216 --> 00:09:21.616 And overall, 144 00:09:21.616 --> 00:09:26.933 since the beginning of the HIV pandemic, there has been about 85.6 145 00:09:26.933 --> 00:09:31.250 million infections since the beginning of the pandemic. 146 00:09:31.550 --> 00:09:35.100 And in terms of the death toll, there have been about 40.4 147 00:09:35.100 --> 00:09:38.266 million Aids related deaths since the beginning 148 00:09:38.266 --> 00:09:41.266 of the HIV pandemic. 149 00:09:41.866 --> 00:09:44.150 So now we move on to the right. 150 00:09:44.150 --> 00:09:47.116 And here we see the prevalence of HIV 151 00:09:47.116 --> 00:09:50.150 per 100,000 individuals in the United States. 152 00:09:50.550 --> 00:09:54.700 We see that the South in the United States has the highest prevalence. 153 00:09:54.716 --> 00:09:57.900 And so in terms of the incidence, it's about 12.4 154 00:09:57.900 --> 00:10:00.900 per 300,000 individuals. 155 00:10:00.950 --> 00:10:03.600 We see that the West is next. 156 00:10:03.600 --> 00:10:07.283 And then we see the lowest prevalence in the Midwest. 157 00:10:08.300 --> 00:10:10.550 There is also some racial influence. 158 00:10:10.550 --> 00:10:15.616 And the distribution with the highest incidence of 40% of new cases 159 00:10:15.616 --> 00:10:19.433 being found in black, black Americans. 160 00:10:19.766 --> 00:10:24.900 And then that is followed by Hispanics and then the white populations. 161 00:10:24.900 --> 00:10:29.250 And then we find that in multiracial Asian 162 00:10:29.250 --> 00:10:33.766 populations, amongst others, the incidence is much less. 163 00:10:35.483 --> 00:10:38.816 So here we look at the HIV virus structure. 164 00:10:39.266 --> 00:10:42.466 So the HIV virus has this outer membrane. 165 00:10:42.833 --> 00:10:46.433 And on that outer membrane there are these proteins on the surface. 166 00:10:46.733 --> 00:10:49.733 And importantly we have the GG 41. 167 00:10:49.733 --> 00:10:52.050 We have the GP 120. 168 00:10:52.050 --> 00:10:55.350 That's glycoprotein 120 and glycoprotein 41. 169 00:10:55.766 --> 00:10:59.483 These are proteins that are going to help in the integration 170 00:10:59.483 --> 00:11:02.633 of the HIV virus into the host cell. 171 00:11:02.666 --> 00:11:05.666 And we'll look at that in the next slide. 172 00:11:05.866 --> 00:11:10.066 Importantly there are also this nucleic acid 173 00:11:10.066 --> 00:11:14.216 material inside the the virus particle. 174 00:11:14.633 --> 00:11:18.800 And associated with that we have these proteins. 175 00:11:18.800 --> 00:11:20.700 And so we have P seven. 176 00:11:20.700 --> 00:11:25.133 We have this green this green circle here 177 00:11:25.133 --> 00:11:29.000 that represents proteases that are important in the process 178 00:11:29.300 --> 00:11:34.916 that the HIV is going to get into the cell and get integrated. 179 00:11:34.966 --> 00:11:38.100 It's nucleic acid integrated into the host cell. 180 00:11:38.516 --> 00:11:39.600 And these proteins 181 00:11:39.600 --> 00:11:43.316 are going to be important when we start looking at the diagnosis. 182 00:11:43.583 --> 00:11:48.766 And so importantly I want to highlight the GP 120 GP 41. 183 00:11:48.766 --> 00:11:51.200 That's the P 24. 184 00:11:51.200 --> 00:11:56.300 There's the reverse transcriptase that I mentioned converts the RNA into DNA. 185 00:11:56.816 --> 00:11:58.350 And then there's integrase. 186 00:11:58.350 --> 00:12:01.816 And then the proteases that are also important. 187 00:12:03.950 --> 00:12:05.400 So here we take a look 188 00:12:05.400 --> 00:12:08.400 at how the HIV virus actually 189 00:12:08.400 --> 00:12:11.400 integrates into the host cell. 190 00:12:11.866 --> 00:12:16.200 So the HIV virus like we mentioned has the surface proteins. 191 00:12:16.516 --> 00:12:20.750 And importantly here we have the GP 120 192 00:12:20.750 --> 00:12:23.750 and then we have the GP 41. 193 00:12:23.816 --> 00:12:26.816 So what happens is the HIV 194 00:12:27.350 --> 00:12:32.816 gets in contact with the CD positive T cells. 195 00:12:33.166 --> 00:12:36.533 And on the CD positive T cells 196 00:12:36.833 --> 00:12:40.250 there is this membrane protein called the CD4. 197 00:12:40.800 --> 00:12:45.900 And so the glycoprotein 120 is able to interact 198 00:12:45.900 --> 00:12:49.800 and bind to the CD4 on the T cell. 199 00:12:50.183 --> 00:12:52.733 This causes a conformational change. 200 00:12:52.733 --> 00:12:55.733 And this causes the glycoprotein 201 00:12:56.116 --> 00:12:59.933 120 to bind to another structure. 202 00:12:59.933 --> 00:13:04.916 Another transmembrane protein on the CD positive T cell 203 00:13:05.216 --> 00:13:08.933 that is called the CCR five that is a core receptor. 204 00:13:09.350 --> 00:13:14.850 And once that binds, it causes a conformational change and at allows 205 00:13:14.850 --> 00:13:19.066 the GP 41 to then fuze 206 00:13:19.066 --> 00:13:23.700 with the cell membrane of the CD positive T cell. 207 00:13:24.200 --> 00:13:26.866 And once that fusion takes place, 208 00:13:26.866 --> 00:13:30.983 there is the integration of the two cell membranes, 209 00:13:31.216 --> 00:13:36.316 and then a channel is created between the HIV particle on top. 210 00:13:36.650 --> 00:13:40.766 And here we have the CD positive T cell. 211 00:13:41.033 --> 00:13:44.850 And so when that happens it facilitates the creation of a channel 212 00:13:45.116 --> 00:13:50.150 that allows the nucleic acid material inside the HIV 213 00:13:50.150 --> 00:13:53.550 particle to be transferred inside the T cell. 214 00:13:56.300 --> 00:13:57.600 So now let's look at 215 00:13:57.600 --> 00:14:00.800 what actually happens during the replication process. 216 00:14:01.366 --> 00:14:05.216 And so we've seen the mechanism by which the HIV particle 217 00:14:05.216 --> 00:14:09.716 is going to attach to the CD4 positive T cell. 218 00:14:10.066 --> 00:14:14.716 And we've seen that process described in the previous slide. 219 00:14:15.000 --> 00:14:18.716 And so after that integration then you click Acid material 220 00:14:18.716 --> 00:14:21.950 is then released into the host cell. 221 00:14:22.466 --> 00:14:26.150 Once that is released, the reverse transcriptase enzyme 222 00:14:26.150 --> 00:14:29.900 that is a viral enzyme helps in the conversion 223 00:14:29.900 --> 00:14:33.500 or the transcription of the RNA 224 00:14:33.500 --> 00:14:36.500 viral RNA into DNA. 225 00:14:36.650 --> 00:14:41.366 This DNA is then, with the help of host cell proteins, 226 00:14:41.700 --> 00:14:46.366 shuttled into the nucleus of the of the host cell 227 00:14:46.800 --> 00:14:51.766 and within the nucleus of the host cell that viral protein, called the integrase, 228 00:14:52.200 --> 00:14:56.750 helps integrate that nucleic acid material into the host cell genome. 229 00:14:57.083 --> 00:15:02.183 And so at this point, we have the viral nucleic acid material 230 00:15:02.550 --> 00:15:05.966 now being convert, having been converted into DNA 231 00:15:06.266 --> 00:15:09.266 and then integrated into the host cell genome. 232 00:15:09.716 --> 00:15:14.116 Now after it's integrated into the host cell genome, 233 00:15:14.566 --> 00:15:17.900 this can then be transcribed into RNA. 234 00:15:18.316 --> 00:15:21.750 This RNA is then shuttled into the cytoplasm. 235 00:15:22.166 --> 00:15:25.516 And then there is processing of the RNA. 236 00:15:25.766 --> 00:15:30.866 The RNA can then be be translated into proteins. 237 00:15:31.050 --> 00:15:36.900 And then within the cytoplasm of the T cell there is viral particle assembly. 238 00:15:37.350 --> 00:15:40.700 And after the viral particles are assembled 239 00:15:41.000 --> 00:15:43.950 then they can be 240 00:15:43.950 --> 00:15:46.516 pushed out of the of the host cell. 241 00:15:46.516 --> 00:15:49.050 And so they bat out of the host cell. 242 00:15:49.050 --> 00:15:54.716 And once they are released, certain proteases can act on the T cell. 243 00:15:54.833 --> 00:15:57.600 And this results in maturation. 244 00:15:57.600 --> 00:16:00.350 And so after it matures it can go on 245 00:16:00.350 --> 00:16:03.866 and infect other T cells. 246 00:16:04.166 --> 00:16:07.133 And as this process goes on and hijacks 247 00:16:07.133 --> 00:16:10.500 the T cell mCAT, the T the T cell. 248 00:16:10.816 --> 00:16:14.816 And that's leads to eventual destruction of the T cells. 249 00:16:17.033 --> 00:16:17.750 So now we 250 00:16:17.750 --> 00:16:21.000 move on to the HIV infection timeline. 251 00:16:21.500 --> 00:16:24.500 And so here looking at this graph 252 00:16:25.283 --> 00:16:28.616 here we look at the the lines on here 253 00:16:28.700 --> 00:16:33.116 are going to represent the viral particles presence. 254 00:16:33.900 --> 00:16:36.416 And so here we have a very low amount 255 00:16:36.416 --> 00:16:39.600 of the viral particles at the beginning of the infection. 256 00:16:39.866 --> 00:16:43.733 And so this phase where the viral particles are very low 257 00:16:44.066 --> 00:16:46.216 that is called the eclipse phase. 258 00:16:46.216 --> 00:16:49.466 And at this phase there are no markers 259 00:16:49.466 --> 00:16:52.666 that are present at appreciable levels 260 00:16:52.850 --> 00:16:55.966 that can be detected to diagnose HIV. 261 00:16:56.416 --> 00:17:01.066 And so in this in this phase that is the eclipse phase, we do not have 262 00:17:01.066 --> 00:17:04.766 the markers present at those at high levels enough to diagnose. 263 00:17:05.366 --> 00:17:08.483 And then we enter what we call the acute phase. 264 00:17:08.933 --> 00:17:12.116 During the acute phase a patient may show symptoms. 265 00:17:12.300 --> 00:17:14.450 And some of the symptoms are outlined 266 00:17:14.450 --> 00:17:17.866 on the left here and some others are shown on here. 267 00:17:18.316 --> 00:17:23.933 And so here that is the first point where markers can be detected in blood. 268 00:17:24.466 --> 00:17:27.316 And it's important to note that 269 00:17:27.316 --> 00:17:32.033 because of these symptoms, patients at that stage may seek medical help. 270 00:17:32.816 --> 00:17:36.416 And then beyond the acute phase 271 00:17:36.566 --> 00:17:39.566 you enter this chronic phase. 272 00:17:39.983 --> 00:17:41.416 And so there's this period 273 00:17:41.416 --> 00:17:44.866 between the acute and the chronic where there are no symptoms. 274 00:17:45.233 --> 00:17:48.250 And for the most part during the chronic phase there are no 275 00:17:48.266 --> 00:17:53.333 there are no symptoms until the disease progresses to the to the aid stage. 276 00:17:53.450 --> 00:17:58.200 And so what happens during the this this phase that we are seeing here 277 00:17:58.616 --> 00:18:03.116 is that you have that process that we looked at in the previous slide 278 00:18:03.116 --> 00:18:08.900 going on the HIV virus as continuously getting into the T cells. 279 00:18:09.200 --> 00:18:12.200 More HIV particles are being produced. 280 00:18:12.200 --> 00:18:14.966 And then the viral counts are going up. 281 00:18:14.966 --> 00:18:19.100 And then the CD4 positive T cell counts are going down. 282 00:18:19.516 --> 00:18:23.250 And so here you have that progression increasing an increase 283 00:18:23.250 --> 00:18:24.950 in the viral particles. 284 00:18:24.950 --> 00:18:30.766 And depending on the type of HIV infection that you have what we call 285 00:18:30.766 --> 00:18:34.333 the set point, that is the background virus 286 00:18:34.350 --> 00:18:37.700 particle levels is going to vary. 287 00:18:37.950 --> 00:18:40.966 And so for HIV one that we saw has 288 00:18:41.216 --> 00:18:44.516 a higher replication rate as compared to HIV two. 289 00:18:44.716 --> 00:18:49.283 The set point is going to be much higher for the HIV type one. 290 00:18:51.450 --> 00:18:52.166 So now we 291 00:18:52.166 --> 00:18:55.166 move on to look at the care cascade. 292 00:18:55.200 --> 00:18:58.500 So as Laboratorios we are responsible 293 00:18:58.500 --> 00:19:02.116 for helping diagnose the HIV infection. 294 00:19:02.450 --> 00:19:06.266 And that is critical because until a patient is diagnosed 295 00:19:06.266 --> 00:19:09.266 with HIV, they cannot seek care. 296 00:19:10.300 --> 00:19:10.733 Okay. 297 00:19:10.733 --> 00:19:15.983 And so that is a very vital stage in the care cascade for HIV. 298 00:19:16.250 --> 00:19:18.983 And so after the HIV is diagnosed 299 00:19:18.983 --> 00:19:23.116 then there is the opportunity for the patient to start treatment. 300 00:19:23.450 --> 00:19:27.916 And as the as the as the cycle shows, 301 00:19:28.066 --> 00:19:31.350 it's important that the medication as it had to. 302 00:19:31.733 --> 00:19:35.250 And then it's important that they continuously seek 303 00:19:35.750 --> 00:19:39.116 medical care and that they are continuously 304 00:19:39.116 --> 00:19:42.116 monitored. 305 00:19:42.316 --> 00:19:44.150 So now let us look at 306 00:19:44.150 --> 00:19:47.150 screening guidelines for HIV. 307 00:19:47.150 --> 00:19:50.450 So here we look at two two recommendations. 308 00:19:50.450 --> 00:19:53.450 The first recommendation is recommendation from the CDC. 309 00:19:53.933 --> 00:19:57.866 And this is endorsed by other associations 310 00:19:57.866 --> 00:20:02.416 like the American Academy for Family Physicians amongst others. 311 00:20:02.750 --> 00:20:07.283 And so the they recommend testing in individuals 312 00:20:07.816 --> 00:20:11.300 between the ages of 13 and 64 years. 313 00:20:11.633 --> 00:20:14.300 They also recommend testing 314 00:20:14.300 --> 00:20:18.266 and patients that are particularly at high risk 315 00:20:18.683 --> 00:20:21.683 and also in pregnant individuals. 316 00:20:22.066 --> 00:20:25.066 And then the United States 317 00:20:25.066 --> 00:20:29.416 Preventive Services Task Force also has these recommendations. 318 00:20:29.416 --> 00:20:30.233 And you'll notice that 319 00:20:30.233 --> 00:20:34.250 the recommendations that we have here are somewhat similar to what we have above. 320 00:20:34.500 --> 00:20:38.150 Just that the age the age brackets are slightly different. 321 00:20:38.400 --> 00:20:42.016 And so for all individuals, the recommendation is to test for 322 00:20:42.450 --> 00:20:45.916 individuals between 15 and 65. 323 00:20:46.350 --> 00:20:50.966 And then for individuals that are at risk are the at high risk 324 00:20:51.116 --> 00:20:55.200 that are less than the age of 15 or greater than the age of 65. 325 00:20:55.466 --> 00:20:58.050 Then testing is also recommended. 326 00:20:58.050 --> 00:21:03.233 And then for pregnant immune individuals, testing is recommended, including testing 327 00:21:03.233 --> 00:21:06.833 for individuals that show up at the labor 328 00:21:07.016 --> 00:21:10.016 ward with unknown HIV status. 329 00:21:12.950 --> 00:21:16.283 So here, before we go into the diagnostics, 330 00:21:16.433 --> 00:21:19.516 we again look at the HIV particle. 331 00:21:19.800 --> 00:21:24.266 And importantly, that these glycoproteins that are on the surface, 332 00:21:24.566 --> 00:21:29.600 there are important proteins like the p24 which forms the capsid 333 00:21:29.816 --> 00:21:35.600 that covers the all that surrounds the viral nucleic acid material. 334 00:21:35.783 --> 00:21:38.600 And these are going to come up as we start 335 00:21:38.600 --> 00:21:42.750 looking at targets for HIV assays. 336 00:21:43.100 --> 00:21:48.233 And so importantly we'll discuss detection of anti HIV AGM. 337 00:21:48.666 --> 00:21:52.066 We'll discuss the detection of anti HIV IgG. 338 00:21:52.433 --> 00:21:56.866 We'll also discuss the detection of protein the P24 339 00:21:57.233 --> 00:22:00.233 and then the viral RNA. 340 00:22:01.666 --> 00:22:04.850 So before we get into the diagnostic tests 341 00:22:05.150 --> 00:22:09.200 it's important to review the slide and look at the markers 342 00:22:09.200 --> 00:22:13.366 and be familiar with at what stage of the infection 343 00:22:13.366 --> 00:22:18.050 the various markers are present and at what stage they are detectable. 344 00:22:18.566 --> 00:22:21.533 And so it's important to note that 345 00:22:21.533 --> 00:22:26.366 the other eclipse stage, these markers that we see on the on 346 00:22:26.366 --> 00:22:30.266 the graph, are not detectable during that eclipse phase. 347 00:22:30.800 --> 00:22:33.616 And then beyond the eclipse phase, 348 00:22:33.616 --> 00:22:37.916 the first marker that is detectable as the viral RNA. 349 00:22:38.266 --> 00:22:42.900 And so here we see the viral RNA increase 350 00:22:42.900 --> 00:22:47.116 up to a peak here around the the 20 to 30. 351 00:22:47.300 --> 00:22:50.150 And then at reduces. 352 00:22:50.150 --> 00:22:53.366 And then the next marker that is going to be detectable 353 00:22:53.366 --> 00:22:56.366 is going to be the P 24. 354 00:22:56.550 --> 00:22:59.633 And so the P 24 that is the capsid protein. 355 00:23:00.233 --> 00:23:05.000 And that is going to be increased especially during the acute phase. 356 00:23:05.416 --> 00:23:10.150 And then after that acute phase the patient starts to circumvent. 357 00:23:10.500 --> 00:23:14.600 And seroconversion means that the patient starts producing 358 00:23:14.600 --> 00:23:17.966 antibodies against the HIV proteins 359 00:23:18.266 --> 00:23:20.966 and other components of the HIV. 360 00:23:20.966 --> 00:23:25.883 And so the first antibody that is produced is going to be IgG. 361 00:23:26.816 --> 00:23:29.550 And further into the infection 362 00:23:29.550 --> 00:23:32.516 then IgG is going to be produced. 363 00:23:32.516 --> 00:23:36.466 And so the IgG AGM rises and then it falls. 364 00:23:36.466 --> 00:23:42.150 And then the IgG is going to be detectable across the infection. 365 00:23:42.983 --> 00:23:47.750 And so here looking at the timeline and the image below. 366 00:23:48.050 --> 00:23:52.516 So you notice that the nucleic acid as what is detectable first. 367 00:23:52.950 --> 00:23:55.616 And then we'll look at the P 368 00:23:55.616 --> 00:23:58.616 24 the IGA MiG that will be next. 369 00:23:58.916 --> 00:24:02.250 And then next you will have assays 370 00:24:02.250 --> 00:24:06.450 that are able to detect just IgG and IgG. 371 00:24:06.750 --> 00:24:11.033 And then here you have assays that are able to detect just IgG. 372 00:24:11.333 --> 00:24:14.250 And then finally the least sensitive 373 00:24:14.250 --> 00:24:17.550 is going to be western blotting assays. 374 00:24:17.933 --> 00:24:20.000 And those are no longer recommended. 375 00:24:22.583 --> 00:24:25.950 So there have been generations of tests for HIV. 376 00:24:25.950 --> 00:24:28.950 And I'm going to walk you through the various iterations. 377 00:24:29.366 --> 00:24:31.850 So the first generation test 378 00:24:31.850 --> 00:24:34.850 was sensitive for IgG antibodies. 379 00:24:35.366 --> 00:24:39.683 And so here there was a viral lysate that was immobilized 380 00:24:39.683 --> 00:24:41.700 on some solid support. 381 00:24:41.700 --> 00:24:45.750 And then you'd have the STS, the patient sample 382 00:24:46.050 --> 00:24:50.850 that would have IgG against those virus lysates. 383 00:24:51.166 --> 00:24:53.866 And then you would have a detection antibody 384 00:24:53.866 --> 00:24:58.316 that would come in and form essentially a sandwich structure. 385 00:24:58.583 --> 00:25:01.583 And then this would be labeled with some kind of, 386 00:25:01.733 --> 00:25:05.000 transducer that would give a measurable signal. 387 00:25:05.516 --> 00:25:08.116 And then we move on to the second generation. 388 00:25:08.116 --> 00:25:11.933 So the second generation was an improvement on the first generation, 389 00:25:11.933 --> 00:25:16.200 in that the second generation was able to detect antibodies 390 00:25:16.616 --> 00:25:20.033 that are produced against HIV one and HIV two. 391 00:25:20.366 --> 00:25:23.816 However, it's important to note here that the second generation 392 00:25:23.816 --> 00:25:26.816 still detected only IgG. 393 00:25:27.300 --> 00:25:30.300 And then we move on to the third generation tests. 394 00:25:30.416 --> 00:25:34.850 So the third generation tests expanded on that IgG 395 00:25:35.366 --> 00:25:38.366 and were able to detect exams. 396 00:25:38.450 --> 00:25:41.450 And so like we saw in the course of the infection 397 00:25:41.550 --> 00:25:46.250 exams are produced first and then ECGs are then produced. 398 00:25:46.850 --> 00:25:51.600 And so it was an important milestone in HIV assays. 399 00:25:52.133 --> 00:25:55.133 And then we move on to the fourth generation tests. 400 00:25:55.250 --> 00:25:58.433 So the fourth generation test for the was the first test 401 00:25:58.700 --> 00:26:01.666 that introduced HIV protein. 402 00:26:01.666 --> 00:26:05.550 And so in this case the P 24 was introduced in this RC. 403 00:26:06.083 --> 00:26:10.583 And so here we are detecting both IgG AGM. 404 00:26:10.850 --> 00:26:14.366 And finally we are also detecting the P 24. 405 00:26:14.900 --> 00:26:18.116 An important thing to note with all these assays is 406 00:26:18.116 --> 00:26:21.750 that they were producing a single readout. 407 00:26:22.166 --> 00:26:24.483 And so in for example, the 408 00:26:26.066 --> 00:26:27.766 second to fourth generation 409 00:26:27.766 --> 00:26:31.650 where you have more than one targets being detected. 410 00:26:31.950 --> 00:26:34.950 The readout was a single readout. So 411 00:26:35.750 --> 00:26:38.516 with a positive test, there was no way of telling 412 00:26:38.516 --> 00:26:41.866 which of the markers were present in the sample. 413 00:26:45.200 --> 00:26:46.850 So here we look at a table 414 00:26:46.850 --> 00:26:51.000 that summarizes these tests that we have looked at. 415 00:26:51.600 --> 00:26:54.166 And so like we saw 416 00:26:54.166 --> 00:26:56.783 we saw in the previous slide 417 00:26:56.783 --> 00:27:01.050 we have the first we discussed the first to the fourth generation test. 418 00:27:01.316 --> 00:27:03.500 And I'll talk about the fifth generation 419 00:27:03.500 --> 00:27:06.500 test as we move as we move through the presentation. 420 00:27:06.833 --> 00:27:14.150 And so importantly, the sensitivity of this RC has remained 421 00:27:14.333 --> 00:27:19.966 relatively similar across the third to that through the fifth generation. 422 00:27:20.450 --> 00:27:23.816 And then when we look at the sensitivity, 423 00:27:24.116 --> 00:27:29.116 we've moved from about 99% up to 99.8 424 00:27:29.116 --> 00:27:32.416 and then 100% in the fifth generation assays. 425 00:27:32.866 --> 00:27:35.966 And then when we look at the negative window, 426 00:27:36.116 --> 00:27:39.233 this is describing that period within 427 00:27:39.233 --> 00:27:43.100 which the HIV between infection and 428 00:27:43.400 --> 00:27:46.100 and running the assay within which 429 00:27:46.100 --> 00:27:49.100 the HIV infection is undetectable. 430 00:27:49.200 --> 00:27:55.133 And so for the HIV first generation test it was about 8 to 10 weeks. 431 00:27:55.316 --> 00:27:59.000 And we've seen a reduction in that up to about two weeks. 432 00:27:59.366 --> 00:28:02.416 And then we discussed the targets for these assays. 433 00:28:02.900 --> 00:28:06.950 And like we mentioned there's a single readout for these assays. 434 00:28:07.283 --> 00:28:10.283 And then on the lower side it describes 435 00:28:10.283 --> 00:28:13.283 the the confirmation tests for these assays. 436 00:28:13.500 --> 00:28:17.416 And so for the first generation and then the second generation 437 00:28:17.666 --> 00:28:20.850 there was western blotting and immunofluorescence 438 00:28:21.166 --> 00:28:25.216 and some Eliza assays that were used as conformation assays. 439 00:28:25.700 --> 00:28:29.266 And a similar thing as seen with the third generation. 440 00:28:29.716 --> 00:28:32.416 However when we get to the fourth generation, 441 00:28:32.416 --> 00:28:35.416 there is a differentiation assay that will be looking at 442 00:28:36.000 --> 00:28:39.450 that will be looking at and that is an immuno assay 443 00:28:39.450 --> 00:28:45.150 that is used to differentiate between the that is used to confirm the 444 00:28:45.533 --> 00:28:50.716 the diagnosis and also helps differentiate between HIV one and HIV two. 445 00:28:51.083 --> 00:28:54.083 There can also be nucleic acid amplification. 446 00:28:54.116 --> 00:28:59.633 And similar confirmatory tests can be seen with the fifth generation testing. 447 00:28:59.783 --> 00:29:02.900 And we'll talk more about the fifth generation test as we move along. 448 00:29:04.366 --> 00:29:06.116 So here we are going to look 449 00:29:06.116 --> 00:29:10.366 at some examples of the third and then fourth generation tests. 450 00:29:10.850 --> 00:29:14.066 And so firstly we take a look at the third generation tests. 451 00:29:14.483 --> 00:29:19.200 So with a third generation test we are detecting IgG and then AGM. 452 00:29:19.766 --> 00:29:24.266 And so here we have a rapid test that is the or a quick test. 453 00:29:24.600 --> 00:29:28.700 And importantly we have a patient sample that is applied here. 454 00:29:29.250 --> 00:29:33.750 And as the patient sample is applied it moves by capillary action. 455 00:29:34.166 --> 00:29:36.800 It interacts with these gold 456 00:29:36.800 --> 00:29:39.983 nanoparticles that have protein A attached. 457 00:29:40.283 --> 00:29:43.950 And so protein A is going to bind to IgG 458 00:29:43.950 --> 00:29:47.033 IgG AGM antibodies in general. 459 00:29:47.450 --> 00:29:53.216 And so once that interacts it moves on to the test line. 460 00:29:53.633 --> 00:29:56.716 Now the test line has away Biden 461 00:29:57.150 --> 00:29:59.933 conjugated with HIV peptides. 462 00:29:59.933 --> 00:30:02.816 And so if the patient has HIV 463 00:30:02.816 --> 00:30:05.816 and the patient has HIV antibodies, 464 00:30:06.116 --> 00:30:09.416 then the antibodies are going to bind to 465 00:30:09.616 --> 00:30:13.316 these HIV peptides that are forming the test line. 466 00:30:13.733 --> 00:30:17.216 And because of the earlier interaction with these gold particles, there's 467 00:30:17.216 --> 00:30:21.600 going to be the immobilization of those gold particles on the test line. 468 00:30:22.016 --> 00:30:25.550 And then we move on to the control line on the control line. 469 00:30:26.750 --> 00:30:29.000 We have anti-human antibodies. 470 00:30:29.000 --> 00:30:34.016 And so these anti-human antibodies on the control line are going to bind the 471 00:30:34.016 --> 00:30:39.466 excess antibody gold particles that move beyond the beyond the test line. 472 00:30:39.900 --> 00:30:42.900 And so in reading these tests 473 00:30:42.916 --> 00:30:48.000 you expect to see two bands and positive patients. 474 00:30:48.266 --> 00:30:50.850 And then you expect to see just one band. 475 00:30:50.850 --> 00:30:55.650 That is the control band in a patient that is negative. 476 00:30:56.000 --> 00:30:58.700 The control band must always appear. 477 00:30:58.700 --> 00:31:02.416 That says as validation for the assay. 478 00:31:04.916 --> 00:31:06.266 Now we take a look 479 00:31:06.266 --> 00:31:09.533 at the fourth generation tests. 480 00:31:10.016 --> 00:31:13.500 And so it's important to note here that the fourth generation tests, 481 00:31:14.150 --> 00:31:18.600 both are detecting both antigens and then antibodies. 482 00:31:19.100 --> 00:31:24.433 And so looking here we are looking at automated systems and some examples. 483 00:31:24.450 --> 00:31:25.800 These are just examples. 484 00:31:25.800 --> 00:31:28.100 And so we have the Abbott Architects. 485 00:31:28.100 --> 00:31:30.683 We have the Siemens platform here. 486 00:31:30.683 --> 00:31:35.966 And importantly the test time is less than 30 minutes 487 00:31:35.966 --> 00:31:41.333 for the Abbott architect platform for the Siemens platform. 488 00:31:41.333 --> 00:31:43.400 It's less than an hour. 489 00:31:43.400 --> 00:31:46.650 The targets that are being detected are going to be similar. 490 00:31:46.650 --> 00:31:48.466 It's a full generation test. 491 00:31:48.466 --> 00:31:53.516 So we expect that we are detecting the HIV p24 antigen. 492 00:31:53.816 --> 00:31:58.950 And we are also detecting antibodies for HIV one and HIV two. 493 00:31:59.700 --> 00:32:02.950 And then the sensitivities are shown here. 494 00:32:02.966 --> 00:32:06.300 And so those are those shows similar performance. 495 00:32:06.683 --> 00:32:10.666 And then the specificities are also similar for both platforms. 496 00:32:11.066 --> 00:32:14.783 And here we see the sample volume requirements 497 00:32:14.783 --> 00:32:19.100 are 150 microliters as opposed to 175 Microliters. 498 00:32:19.466 --> 00:32:24.566 And on here the detection system, the signal readout is going to be 499 00:32:24.566 --> 00:32:30.116 a Chemin luminescent readout, which is based on, micro particle. 500 00:32:32.850 --> 00:32:35.850 So now we move on to the differentiation test. 501 00:32:35.850 --> 00:32:39.000 And so the differentiation test is going to help us distinguish 502 00:32:39.000 --> 00:32:42.566 between HIV one and HIV two infection. 503 00:32:43.166 --> 00:32:45.683 And so this is a rapid test again. 504 00:32:45.683 --> 00:32:49.516 And looking here we have a sample application part. 505 00:32:49.516 --> 00:32:51.866 We have a buffer application part. 506 00:32:51.866 --> 00:32:56.033 And again it's important to note that this test is tested 507 00:32:56.033 --> 00:32:59.033 for antibodies in the patient sample 508 00:32:59.300 --> 00:33:02.633 against these peptides or proteins. 509 00:33:03.200 --> 00:33:06.666 And so here for HIV type one there's 510 00:33:06.683 --> 00:33:10.066 glycoprotein 41 glycoprotein one and 60. 511 00:33:10.466 --> 00:33:12.950 And then we have the p 24. 512 00:33:12.950 --> 00:33:14.633 That is the capsid protein. 513 00:33:14.633 --> 00:33:18.950 And then here we have p 31 that is a polymerase protein. 514 00:33:19.466 --> 00:33:24.516 And so for the HIV type two we have the corresponding proteins as well. 515 00:33:24.533 --> 00:33:28.066 We have the GP 140 and GP 36. 516 00:33:28.733 --> 00:33:32.450 Now to diagnose or to confirm 517 00:33:32.450 --> 00:33:35.450 HIV one infection, 518 00:33:35.600 --> 00:33:39.866 it's important that we have antibodies in the patient sample 519 00:33:40.250 --> 00:33:43.133 against both glycoproteins. 520 00:33:43.133 --> 00:33:49.066 The GP 160 and 41 or we have the 521 00:33:50.033 --> 00:33:53.633 we have a glycoprotein being reactive. 522 00:33:53.900 --> 00:33:57.050 And then we have either the p 31 523 00:33:57.316 --> 00:34:00.316 or P 24 being present. 524 00:34:00.983 --> 00:34:04.616 And then for HIV type two we need to see 525 00:34:04.616 --> 00:34:08.216 both the GP 36 and GP 140. 526 00:34:08.550 --> 00:34:11.550 And being reactive. 527 00:34:13.366 --> 00:34:14.750 So now let's move on 528 00:34:14.750 --> 00:34:17.933 and look at the HIV testing algorithm. 529 00:34:18.683 --> 00:34:22.016 So here the initial screen and test 530 00:34:22.466 --> 00:34:25.466 that is recommended as the 531 00:34:26.266 --> 00:34:29.466 antigen antibody combination assay. 532 00:34:29.483 --> 00:34:34.516 And so here we are testing for the HIV one antibody. 533 00:34:34.516 --> 00:34:37.050 We are testing for the HIV two antibody. 534 00:34:37.050 --> 00:34:41.150 And then we are testing for the HIV one P 24. 535 00:34:41.483 --> 00:34:46.650 And so if this screen is negative then HIV infection is unlikely. 536 00:34:47.183 --> 00:34:51.416 And in situations where an acute infection is suspected 537 00:34:51.683 --> 00:34:54.833 then nucleic acid amplification will be recommended. 538 00:34:55.516 --> 00:34:59.850 And then we look on this other side where we have a positive screen. 539 00:35:00.316 --> 00:35:03.833 After a positive screen it's important that the differentiation 540 00:35:03.833 --> 00:35:07.433 assay that we just looked at on the previous slide is run. 541 00:35:07.883 --> 00:35:10.800 And so with the differentiation assay, 542 00:35:10.800 --> 00:35:16.400 if HIV one antibodies are present then HIV one is detected. 543 00:35:16.400 --> 00:35:19.400 That is confirmation of HIV one infection. 544 00:35:19.583 --> 00:35:23.716 If the HIV two antibodies are detected that is confirmation. 545 00:35:24.150 --> 00:35:28.883 And then for HIV one HIV two antibodies are detected. 546 00:35:29.183 --> 00:35:32.783 That means the patient is infected with HIV one 547 00:35:33.466 --> 00:35:36.166 and the and HIV two. 548 00:35:36.166 --> 00:35:40.100 And then it's important that you can also run 549 00:35:40.350 --> 00:35:45.616 nucleic acid amplification testing to differentiate between the HIV 550 00:35:45.616 --> 00:35:49.133 one presence and the HIV two presence that can be run as well. 551 00:35:49.583 --> 00:35:52.766 And then we move on to the extreme end 552 00:35:52.766 --> 00:35:57.000 where the differentiation assay is indeterminate. 553 00:35:57.416 --> 00:36:00.616 And so when you have an indeterminate differentiation assay, 554 00:36:00.983 --> 00:36:05.333 the next step would be to run a nucleic acid amplification test. 555 00:36:05.716 --> 00:36:10.400 And if the nucleic acid amplification test comes out as negative, 556 00:36:10.666 --> 00:36:13.650 then that would be an indication 557 00:36:13.650 --> 00:36:17.066 that the HIV infection is ruled out. 558 00:36:17.366 --> 00:36:23.150 And if the testing becomes positive or you test positive, 559 00:36:23.416 --> 00:36:27.083 then that is an indication of an acute infection. 560 00:36:29.783 --> 00:36:31.016 Now let's take a 561 00:36:31.016 --> 00:36:34.016 look at the fifth generation test. 562 00:36:34.050 --> 00:36:39.350 So the fifth generation test is able to simultaneously detect 563 00:36:39.350 --> 00:36:42.466 and report a screen as well 564 00:36:42.466 --> 00:36:46.133 as three individual HIV results. 565 00:36:46.583 --> 00:36:50.866 And so we saw in the previous test in the first generation up 566 00:36:50.866 --> 00:36:56.000 to the fourth generation testing, we saw that there a single readout. 567 00:36:56.000 --> 00:36:58.366 So you cannot tell whether it's the antibody 568 00:36:58.366 --> 00:37:01.816 that is present or the protein that is present. 569 00:37:02.216 --> 00:37:05.216 However, with the fifth generation test, 570 00:37:05.216 --> 00:37:09.000 there is a readout that gives a combined result. 571 00:37:09.383 --> 00:37:16.616 There is also individual readings for the p24 antigen for the HIV one. 572 00:37:16.950 --> 00:37:22.200 And then we are also able to get readings for the HIV one antibodies. 573 00:37:22.283 --> 00:37:25.283 And then HIV two antibodies. 574 00:37:25.966 --> 00:37:28.500 And so importantly this includes 575 00:37:28.500 --> 00:37:31.500 HIV v1 and V2 differentiation. 576 00:37:32.183 --> 00:37:36.416 And then there is enhanced sensitivity for p24 577 00:37:36.416 --> 00:37:39.500 antigen detection in the fifth generation assays. 578 00:37:40.016 --> 00:37:44.300 And so as we see in the image here it is a beat up system. 579 00:37:44.550 --> 00:37:47.850 And this is going to be a fluorescence based system. 580 00:37:48.200 --> 00:37:53.066 And so there is going to be a different signal for each of these beads. 581 00:37:53.450 --> 00:37:58.950 And each bead is coated with ligands that are going to help 582 00:37:59.183 --> 00:38:03.350 to detect the individual individual targets. 583 00:38:03.383 --> 00:38:07.666 And so in this case as we look at these blue blue beads here, 584 00:38:07.800 --> 00:38:11.066 these are going to help in the detection or facilitate 585 00:38:11.066 --> 00:38:15.600 the detection of HIV one group M antibodies. 586 00:38:15.916 --> 00:38:21.150 And then as we move on we see HIV group all antibodies. 587 00:38:21.150 --> 00:38:24.316 We see these beads that are going to be helpful 588 00:38:24.316 --> 00:38:28.650 in detecting the HIV p24 antigen. 589 00:38:28.766 --> 00:38:34.133 And then we have beads that are going to help in detecting HIV to antibodies. 590 00:38:34.400 --> 00:38:39.466 And so we have individual readouts that are being given by these beads. 591 00:38:39.716 --> 00:38:43.100 And that's the advantage of the fifth generation test. 592 00:38:46.166 --> 00:38:46.916 So here 593 00:38:46.916 --> 00:38:50.666 we look at test and in particular populations. 594 00:38:50.666 --> 00:38:53.666 And particularly we are interested in infants here. 595 00:38:54.300 --> 00:38:57.300 So for newborn babies 596 00:38:57.466 --> 00:39:00.466 there can be the transfer of antibodies 597 00:39:00.716 --> 00:39:04.583 from the pregnant mother into the fetus. 598 00:39:04.766 --> 00:39:07.733 And so when the baby is born the baby 599 00:39:07.733 --> 00:39:11.150 then carries antibodies to the HIV. 600 00:39:11.816 --> 00:39:14.816 And how does this affect testing. 601 00:39:15.000 --> 00:39:18.233 If the baby has antibodies to the HIV, 602 00:39:18.600 --> 00:39:23.600 then the baby is going to test positive on the screens, 603 00:39:23.866 --> 00:39:28.516 even though the baby might not have HIV infection. 604 00:39:28.883 --> 00:39:32.866 And so for infants that are in this category, 605 00:39:33.083 --> 00:39:37.916 it's important that nucleic acid amplification testing be done. 606 00:39:38.266 --> 00:39:40.950 And it is recommended that this kind of testing 607 00:39:40.950 --> 00:39:43.966 be done for the first 18 months of life. 608 00:39:44.333 --> 00:39:47.566 And so the test and recommendation is to test at birth. 609 00:39:48.050 --> 00:39:53.633 Test again at six weeks, and then test again at 4 to 6 months. 610 00:39:54.083 --> 00:39:57.083 And if all these tests are negative, 611 00:39:57.266 --> 00:40:00.450 then prophylaxis can be discontinued. 612 00:40:03.383 --> 00:40:04.350 So now we move 613 00:40:04.350 --> 00:40:07.583 over to look at the nucleic acid amplification test. 614 00:40:07.583 --> 00:40:10.700 And we've seen that being mentioned in the previous slide. 615 00:40:10.700 --> 00:40:13.700 So we are going to shed some light on that. 616 00:40:13.883 --> 00:40:16.616 And so as we saw in the algorithm 617 00:40:16.616 --> 00:40:21.200 it can be used at the third step of the HIV test an algorithm. 618 00:40:21.566 --> 00:40:26.266 And it is particularly important for the diagnosis of acute HIV infection. 619 00:40:26.866 --> 00:40:29.783 And since this is a quantitative test 620 00:40:29.783 --> 00:40:33.350 it can help in the monitoring of viral loads. 621 00:40:34.016 --> 00:40:37.100 So here we see an example of a test kit. 622 00:40:37.316 --> 00:40:41.066 So this is the Optima HIV one quantitative kit. 623 00:40:41.416 --> 00:40:46.050 And so here it detects HIV RNA from group M 624 00:40:47.366 --> 00:40:50.550 group N and group O of the HIV one. 625 00:40:51.016 --> 00:40:57.616 And just some statistics or some numerical on the on the test performance. 626 00:40:57.833 --> 00:41:02.550 So we see the limit of detection as being 17 copies per ML. 627 00:41:02.900 --> 00:41:07.100 And then the measuring range is going to be 30 628 00:41:07.100 --> 00:41:10.916 to about 10 million copies per ML. 629 00:41:11.216 --> 00:41:15.500 And this is an example of a platform that is used to run this. 630 00:41:15.500 --> 00:41:17.783 This is a Panther fusion platform. 631 00:41:19.516 --> 00:41:22.400 And for patients that are living with HIV, 632 00:41:22.400 --> 00:41:26.700 the nucleic acid amplification testing can have some utility. 633 00:41:27.083 --> 00:41:31.066 So prior to the initiation of treatment, it's important 634 00:41:31.066 --> 00:41:34.816 that viral load baselines be established. 635 00:41:34.816 --> 00:41:38.450 And so the nucleic acid amplification testing is important 636 00:41:38.450 --> 00:41:41.450 for establishing viral loads prior to therapy. 637 00:41:41.600 --> 00:41:46.400 And then viral load check in in the course of therapy is also important. 638 00:41:46.400 --> 00:41:51.300 So viral load check every 4 to 8 weeks after treatment initiation 639 00:41:51.566 --> 00:41:55.700 until the viral load is undetectable as important. 640 00:41:55.966 --> 00:42:00.350 And in patients that are stable and on antiretroviral therapy 641 00:42:00.683 --> 00:42:03.683 it's important that the viral load be measured 642 00:42:04.283 --> 00:42:07.283 every 3 to 4 months. 643 00:42:09.683 --> 00:42:13.066 Now, after HIV diagnosis, what's next? 644 00:42:13.800 --> 00:42:19.133 It's important to gather the history, medical history of the patient. 645 00:42:19.400 --> 00:42:24.416 It's important to perform a physical to set a baseline health level. 646 00:42:24.900 --> 00:42:29.700 And then beyond that, it's important to establish the HIV RNA load. 647 00:42:30.016 --> 00:42:33.750 And this is important to monitor the therapy. 648 00:42:34.100 --> 00:42:38.816 And it's also important to do cell counts and also determine 649 00:42:39.050 --> 00:42:42.500 the CD4 positive T lymphocyte counts. 650 00:42:42.800 --> 00:42:45.150 As we saw in the previous slides. 651 00:42:45.150 --> 00:42:49.283 Those are the cells that are targeted by the HIV virus. 652 00:42:49.666 --> 00:42:54.683 And it's important to also do serological testing for hepatitis. 653 00:42:54.950 --> 00:42:58.466 And in these patients if the immune system is compromised 654 00:42:58.733 --> 00:43:02.550 then opportunistic infections can become an issue. 655 00:43:02.566 --> 00:43:05.450 So it's important to monitor these patients. 656 00:43:05.450 --> 00:43:10.300 And for infections that have some kind of a therapy, 657 00:43:10.350 --> 00:43:13.433 it's important to make sure that those are also being treated. 658 00:43:14.066 --> 00:43:16.250 And then there can be genotyping. 659 00:43:16.250 --> 00:43:19.800 Genotyping is particularly important in identifying 660 00:43:20.183 --> 00:43:23.483 drug resistant HIV strains. 661 00:43:23.850 --> 00:43:27.466 And so this can be done to offer that identification. 662 00:43:27.466 --> 00:43:29.633 And that can guide the therapy as well. 663 00:43:31.950 --> 00:43:34.950 So now we move on to HIV therapy. 664 00:43:35.633 --> 00:43:39.233 So the treatment of HIV is done 665 00:43:39.233 --> 00:43:42.716 with these drugs called the antiretroviral drugs. 666 00:43:43.166 --> 00:43:46.250 And so it is termed antiretroviral therapy. 667 00:43:46.883 --> 00:43:50.216 So the art is cocktail of drugs. 668 00:43:50.633 --> 00:43:55.816 And as we will see, there are multiple points that these drugs 669 00:43:55.816 --> 00:43:58.283 are going to act at. 670 00:43:58.283 --> 00:44:01.950 And so the drugs are going to act on seven major points. 671 00:44:02.250 --> 00:44:05.066 And so these are outlined on the slides. 672 00:44:05.066 --> 00:44:09.600 And so importantly the nucleoside reverse transcriptase inhibitors 673 00:44:09.900 --> 00:44:13.466 we have the non-nuclear side reverse transcriptase inhibitors. 674 00:44:13.883 --> 00:44:17.966 There are the protease inhibitors amongst other others. 675 00:44:18.566 --> 00:44:21.950 And it's important to note that the HIV medicines 676 00:44:21.950 --> 00:44:24.950 are going to prevent HIV replication. 677 00:44:25.400 --> 00:44:28.133 If we are preventing HIV replication, 678 00:44:28.133 --> 00:44:31.350 it means that we are reducing the viral loads. 679 00:44:31.650 --> 00:44:34.016 And what does that mean for the patient? 680 00:44:34.016 --> 00:44:39.116 It means that the patient's immune system is going to have a chance to recover. 681 00:44:39.616 --> 00:44:41.450 And recover. 682 00:44:41.450 --> 00:44:44.450 And it can also produce more CD4 cells. 683 00:44:44.783 --> 00:44:49.133 And then when these viral loads are low, 684 00:44:49.616 --> 00:44:52.733 it also reduces the chances of transmission. 685 00:44:53.483 --> 00:44:56.116 And importantly for the therapy 686 00:44:56.116 --> 00:44:59.783 in the last few years there has been the 687 00:45:00.950 --> 00:45:03.233 cubby nowhere to prevent. 688 00:45:03.233 --> 00:45:05.966 And this treatment is a combination therapy. 689 00:45:05.966 --> 00:45:09.800 This was approved as a monthly injection in 2021, 690 00:45:10.283 --> 00:45:13.400 and in 2022 it was approved as, 691 00:45:14.066 --> 00:45:17.066 once every other month dose. 692 00:45:17.250 --> 00:45:20.850 And so this is a significant improvement 693 00:45:21.200 --> 00:45:24.716 over the daily dose dosing that patients 694 00:45:24.950 --> 00:45:27.950 previously had to do. 695 00:45:30.683 --> 00:45:31.883 Another important point 696 00:45:31.883 --> 00:45:35.250 that we want to discuss is next generation sequencing. 697 00:45:35.700 --> 00:45:40.700 So next generation sequencing is particularly important in identifying 698 00:45:40.700 --> 00:45:44.183 HIV genotypes that are susceptible 699 00:45:44.183 --> 00:45:47.933 to particular antiretroviral drugs. 700 00:45:48.233 --> 00:45:52.666 And so this can help identify susceptibility to protease inhibitors, 701 00:45:52.883 --> 00:45:57.300 reverse transcriptase inhibitors and then integrase inhibitors. 702 00:45:57.866 --> 00:46:01.250 Next generation sequencing can also be important 703 00:46:01.500 --> 00:46:06.200 in identifying or detecting low frequency virus populations. 704 00:46:06.833 --> 00:46:10.733 Another important advantage of the next generation sequencing 705 00:46:10.733 --> 00:46:14.866 is that the data that is obtained from the next generation sequencing 706 00:46:15.200 --> 00:46:18.766 can be compared to the gold standard standard database. 707 00:46:19.216 --> 00:46:22.100 That can ensure up to date interpretation 708 00:46:22.100 --> 00:46:26.116 based on the most recent HIV clinical trials. 709 00:46:28.583 --> 00:46:29.100 So now 710 00:46:29.100 --> 00:46:32.100 let us look at prevention of HIV infection. 711 00:46:32.216 --> 00:46:35.900 The first thing that we look at is pre-exposure prophylaxis. 712 00:46:36.266 --> 00:46:40.700 So pre-exposure prophylaxis is when antiretroviral therapy 713 00:46:41.100 --> 00:46:44.783 is given to individuals that are at particularly high 714 00:46:44.783 --> 00:46:47.783 risk of contracting HIV. 715 00:46:49.216 --> 00:46:52.316 And so there are some recommendations. 716 00:46:52.583 --> 00:46:58.816 And so the body weight and then the sexual practices 717 00:46:58.816 --> 00:47:01.950 of the individual are important considerations here. 718 00:47:02.266 --> 00:47:07.016 And so here if you have an individual that is at least 35kg. 719 00:47:07.250 --> 00:47:10.950 And as they engage in anal vaginally sex in the past six months 720 00:47:11.250 --> 00:47:13.950 that satisfy the following criteria, 721 00:47:13.950 --> 00:47:18.650 then the patient might be a candidate for pre-exposure prophylaxis. 722 00:47:19.050 --> 00:47:24.083 And so examples include having a sexual partner that has HIV 723 00:47:24.533 --> 00:47:27.683 and when the bacterial sexually transmitted 724 00:47:27.900 --> 00:47:33.266 infection history in the past six months, and then those with a history 725 00:47:33.266 --> 00:47:38.150 of inconsistent use of condoms are also at particular risk. 726 00:47:38.333 --> 00:47:41.266 And you have other populations, like men 727 00:47:41.266 --> 00:47:44.416 who have sex with other men, amongst others. 728 00:47:46.500 --> 00:47:48.716 And then 729 00:47:48.716 --> 00:47:50.850 we look at individuals that inject, 730 00:47:50.850 --> 00:47:55.350 inject drugs or have a history of drug injection 731 00:47:55.350 --> 00:48:00.450 with a partner who has HIV or who shares injection equipment. 732 00:48:00.766 --> 00:48:05.416 And so for these individuals, it's important that pre-exposure 733 00:48:05.416 --> 00:48:08.416 prophylaxis is administered. 734 00:48:10.666 --> 00:48:14.600 And then we look at a case where there has been exposure. 735 00:48:15.000 --> 00:48:20.000 And so here we look at what we call post exposure prophylaxis. 736 00:48:20.450 --> 00:48:25.016 And so this means taking viral replication blocking medication 737 00:48:25.666 --> 00:48:30.233 that prevent HIV replication after an exposure has happened. 738 00:48:31.100 --> 00:48:34.200 And in a study that was previously published, 739 00:48:34.916 --> 00:48:37.916 the taking of pre-exposure prophylaxis 740 00:48:38.250 --> 00:48:43.166 reduced the risk of HIV acquisition by 81% 741 00:48:43.400 --> 00:48:46.400 in returning US exposures. 742 00:48:46.400 --> 00:48:49.500 And it's important that these kinds of treatment, 743 00:48:49.500 --> 00:48:53.116 the post-exposure prophylaxis, 744 00:48:53.266 --> 00:48:57.766 it's important that it is initiated within two hours of exposure 745 00:48:58.766 --> 00:49:01.766 and no later than 72 hours post exposure. 746 00:49:02.266 --> 00:49:04.816 And then it's important to note 747 00:49:04.816 --> 00:49:08.416 that these regimens are safe. 748 00:49:08.900 --> 00:49:12.950 And then they have minimal side effects, though it's important for the clinicians 749 00:49:12.950 --> 00:49:15.950 to track the side effects of these medications. 750 00:49:16.016 --> 00:49:18.600 And it's recommended that it is 751 00:49:18.600 --> 00:49:21.716 taken for 28 days post exposure. 752 00:49:21.950 --> 00:49:24.766 And within this time, there has to be testing to make sure 753 00:49:24.766 --> 00:49:28.016 that this patient is not testing positive. 754 00:49:29.183 --> 00:49:31.250 So now let us look at HIV 755 00:49:31.250 --> 00:49:35.100 exposure with and without the administration of the Pep. 756 00:49:35.100 --> 00:49:38.333 That is the post exposure prophylaxis. 757 00:49:38.783 --> 00:49:44.116 And so here we are looking at pre cutaneous or mucosal exposure of HIV. 758 00:49:44.633 --> 00:49:47.150 And so here we are looking at the first situation 759 00:49:47.150 --> 00:49:50.216 where the Pep the Pep is not administered. 760 00:49:50.516 --> 00:49:54.166 And so when that is not administered the viral replication is first of all 761 00:49:54.166 --> 00:49:55.200 not blocked. 762 00:49:55.200 --> 00:49:58.550 And then within 48 to 72 hours 763 00:49:58.550 --> 00:50:01.666 of exposure viral replication occurs. 764 00:50:02.183 --> 00:50:05.066 And then viremia will follow. 765 00:50:05.066 --> 00:50:09.300 And so that is within 72 to 1 20 hours of exposure. 766 00:50:09.683 --> 00:50:14.816 And then after that HIV infection is established in the exposed individual. 767 00:50:15.116 --> 00:50:17.550 And so that kind of speaks to the fact 768 00:50:17.550 --> 00:50:20.783 that it's important to start the Pep treatment early. 769 00:50:21.500 --> 00:50:24.916 And then in the case where the Pep treatment is administered 770 00:50:24.916 --> 00:50:28.966 within 72 hours, the viral replication is blocked. 771 00:50:29.366 --> 00:50:32.516 And then the HIV infection is prevented. 772 00:50:33.450 --> 00:50:35.600 And it's important to note that 773 00:50:35.600 --> 00:50:40.316 the HIV Pep treatment should not be delayed. 774 00:50:40.516 --> 00:50:46.016 Whilst we are waiting for the source patient's HIV status. 775 00:50:46.366 --> 00:50:52.550 And then, while the results of the expose workers baseline HIV test, it's unknown. 776 00:50:52.550 --> 00:50:55.550 It's important to start the the 777 00:50:56.400 --> 00:50:58.616 the post-exposure prophylaxis 778 00:50:58.616 --> 00:51:03.450 and then the post-exposure prophylaxis may be discontinued 779 00:51:03.900 --> 00:51:06.800 when the test results subsequently 780 00:51:06.800 --> 00:51:10.650 show that the source patient does not have HIV. 781 00:51:13.316 --> 00:51:14.116 So post 782 00:51:14.116 --> 00:51:18.950 as HIV exposure testing is important. 783 00:51:18.950 --> 00:51:23.000 And that's where we, the libertarians come into the picture. 784 00:51:23.516 --> 00:51:27.866 And so here baseline HIV testing has to be done in the individual 785 00:51:28.250 --> 00:51:31.650 with the anti gene antibody sensitive test. 786 00:51:31.966 --> 00:51:35.700 And like I mentioned the Pep test 787 00:51:35.700 --> 00:51:39.800 must be initiated no longer than 72 hours post exposure. 788 00:51:40.366 --> 00:51:45.000 And after that there has to be testing at that baseline like we mentioned. 789 00:51:45.000 --> 00:51:48.416 There has to be to be tested at the four week period 790 00:51:48.416 --> 00:51:51.800 that has to be tested at the 12 week period. 791 00:51:52.316 --> 00:51:55.316 And then outside the screen and it's important that 792 00:51:56.000 --> 00:51:59.216 outside that baseline, that there should be testing 793 00:51:59.216 --> 00:52:04.050 for general lab testing for blood counts, renal function, 794 00:52:04.316 --> 00:52:09.116 serology for infection with hepatitis B, hepatitis C 795 00:52:09.233 --> 00:52:12.866 and pregnancy test and can also be indicated. 796 00:52:13.316 --> 00:52:17.183 And then it's important to note that clinicians should continue the Pep 797 00:52:17.416 --> 00:52:20.966 and any individuals that are suspected to be seroconversion. 798 00:52:21.416 --> 00:52:25.350 And they have to continue the Pep treatment for individuals 799 00:52:25.616 --> 00:52:29.900 for whom the HIV has not been ruled out even at the week four. 800 00:52:30.500 --> 00:52:33.866 And if unexposed, individual HIV individuals 801 00:52:33.866 --> 00:52:37.400 HIV screening test result is reactive at any time. 802 00:52:37.733 --> 00:52:40.733 It's important that the 803 00:52:40.816 --> 00:52:45.000 as the performance of the FDA approved confirmatory test 804 00:52:45.350 --> 00:52:49.166 that as the differentiation assay that we discussed before. 805 00:52:51.616 --> 00:52:53.150 So we go over the case 806 00:52:53.150 --> 00:52:56.666 study again to finish up this presentation. 807 00:52:57.166 --> 00:53:00.166 So here we have a 30 year old black female 808 00:53:00.416 --> 00:53:04.216 that has been unwell until approximately seven days earlier. 809 00:53:04.766 --> 00:53:08.366 And then she began to have some symptoms like vaginal discharge 810 00:53:08.366 --> 00:53:12.616 followed by a headache, fatigue, sore throat and anorexia. 811 00:53:12.950 --> 00:53:17.116 On the fifth day of symptoms, she went to an outpatient clinic in an urban area. 812 00:53:17.450 --> 00:53:20.450 On examination, she had a vaginal discharge and the 813 00:53:20.483 --> 00:53:24.950 and temperature and remainder of the examination was reportedly normal. 814 00:53:25.466 --> 00:53:28.466 Patient has had multiple sexual partners 815 00:53:28.466 --> 00:53:31.466 and hasn't always used protection for intercourse. 816 00:53:31.800 --> 00:53:35.783 And patient has a history of STDs, gonorrhea and syphilis 817 00:53:36.150 --> 00:53:39.116 that has previously been treated and labs screened 818 00:53:39.116 --> 00:53:42.116 for gonorrhea and syphilis, where negative. 819 00:53:43.400 --> 00:53:45.900 So what would be the next course of action 820 00:53:45.900 --> 00:53:48.900 if HIV is suspected? 821 00:53:49.100 --> 00:53:53.150 The next course would be to run a fourth generation test 822 00:53:53.150 --> 00:53:57.016 that is going to be sensitive for both the P24 823 00:53:57.116 --> 00:54:00.983 and then the HIV one HIV two antibodies. 824 00:54:01.366 --> 00:54:05.300 And so here as the fourth generation lab test was run, 825 00:54:05.866 --> 00:54:11.116 and then the laboratory test came back as positive. 826 00:54:11.366 --> 00:54:15.116 And so after the performance of the fourth generation testing 827 00:54:15.300 --> 00:54:19.500 that comes out positive, what is going to be the next step? 828 00:54:20.100 --> 00:54:23.783 The next step is going to be the differentiation assay. 829 00:54:23.783 --> 00:54:26.783 That's going to be the genius differentiation assay 830 00:54:27.016 --> 00:54:28.616 that can be performed. 831 00:54:28.616 --> 00:54:32.550 And in this case we end up having the HIV one 832 00:54:32.550 --> 00:54:36.300 being positive and then the HIV two being negative. 833 00:54:36.716 --> 00:54:40.650 And so this combination of screen and differentiation 834 00:54:41.000 --> 00:54:46.466 I see it's going to be confirmatory for HIV one infection. 835 00:54:49.166 --> 00:54:49.700 And then 836 00:54:49.700 --> 00:54:52.766 importantly what would be the next course of action. 837 00:54:52.950 --> 00:54:57.566 So the next course of action as to establish care for this patient, 838 00:54:58.016 --> 00:55:00.983 it's important to establish the viral loads. 839 00:55:00.983 --> 00:55:03.983 It's important to get the health history 840 00:55:04.366 --> 00:55:09.450 and do all those labs that we spoke about in the course of this presentation. 841 00:55:09.750 --> 00:55:14.533 And it's also important that the viral load be established. 842 00:55:14.550 --> 00:55:17.550 And then treatment be initiated. 843 00:55:19.250 --> 00:55:21.300 And so to wrap up, we look at progress 844 00:55:21.300 --> 00:55:24.800 that we've made with HIV management over the years. 845 00:55:25.100 --> 00:55:27.983 And so here we look at from a time 846 00:55:27.983 --> 00:55:31.500 from the early 90s to 2019. 847 00:55:31.916 --> 00:55:35.250 And so here we look at this line on the bottom. 848 00:55:35.566 --> 00:55:39.050 And so the line on the bottom here just shows HIV deaths. 849 00:55:39.316 --> 00:55:43.433 And so you notice that from 1990 up until the mid 2000, 850 00:55:43.616 --> 00:55:47.116 there was an increase exponential increase in the death rate. 851 00:55:47.700 --> 00:55:51.866 But then from the 2000, mid 2000 852 00:55:52.133 --> 00:55:55.050 there was a reduction in the death rate. 853 00:55:55.050 --> 00:55:58.966 And this is primarily due to the introduction 854 00:55:58.966 --> 00:56:01.966 of these anti antiretroviral therapies. 855 00:56:02.483 --> 00:56:04.850 And then when we look at the number of people 856 00:56:04.850 --> 00:56:08.333 that are living with HIV, then we see that 857 00:56:08.666 --> 00:56:12.983 the number of people living with HIV has increased over the years. 858 00:56:13.433 --> 00:56:17.716 But then the the rates kind of reduced here in the 2000. 859 00:56:18.233 --> 00:56:23.366 And then the last line, the green line, that is the new infections. 860 00:56:23.700 --> 00:56:26.600 And so here it was increase in but 861 00:56:26.600 --> 00:56:31.500 with education and and and getting people 862 00:56:31.500 --> 00:56:35.600 to be aware of things to do to prevent infection. 863 00:56:36.000 --> 00:56:39.800 Then the rate of new cases has continuously dropped. 864 00:56:40.050 --> 00:56:43.016 And so there has been important progress in the management 865 00:56:43.016 --> 00:56:46.666 of patients living with HIV. And so 866 00:56:47.900 --> 00:56:50.900 that that has been a win over the years. 867 00:56:51.416 --> 00:56:56.116 And then to wrap up, we look at the end in the HIV epidemic. 868 00:56:56.850 --> 00:57:01.666 And so here it's an initiative that the CDC has in place 869 00:57:01.883 --> 00:57:04.816 that is aiming to reduce HIV. 870 00:57:04.816 --> 00:57:09.683 New infections by 75% by 2025 871 00:57:09.833 --> 00:57:12.833 and by 90% in 2030. 872 00:57:13.066 --> 00:57:15.950 And this is a multifaceted approach. 873 00:57:15.950 --> 00:57:21.566 There is a diagnostic approach where the goal is to diagnose people 874 00:57:21.566 --> 00:57:25.766 that are living with HIV, and this gets these patients to get 875 00:57:25.766 --> 00:57:30.016 into therapy and to treat these patients that are diagnosed. 876 00:57:30.316 --> 00:57:34.050 There's the education and also prevent 877 00:57:34.050 --> 00:57:39.050 an HIV infection with Prep and other other avenues. 878 00:57:39.266 --> 00:57:41.716 And then finally there is the response. 879 00:57:41.716 --> 00:57:46.666 And so when there is an HIV hotspot, then there is the response 880 00:57:46.666 --> 00:57:51.716 to rapidly respond to that and contain the outbreak. 881 00:57:54.233 --> 00:57:55.016 And with that, 882 00:57:55.016 --> 00:57:58.216 I thank you for staying with me through this presentation. 883 00:57:58.850 --> 00:57:59.466 Thank you.