Health and medicine
- What is HIV/AIDS?
- What is HIV and AIDS?
- Transmission of HIV
- How HIV infects us: Mucous membranes, dendritic cells, and lymph nodes
- How HIV infects us: CD4 (T-helper) lymphocyte infection
- How HIV kills so many CD4 T cells
- Diagnosing HIV - Concepts and tests
- Treating HIV: Antiretroviral drugs
- HAART treatment for HIV - Who, what, why, when, and how
- Defining AIDS and AIDS defining illnesses
- Immune reconstitution inflammatory syndrome (IRIS) in AIDS
- Preventing an HIV infection
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- I thought the nurse would take a sample of a person's saliva to check whether if you are HIV positive, then how could a person's saliva no transmitting HIV virus?(6 votes)
- "It uses oral fluid, which is slightly different from saliva. Oral fluid, collected from the gumline, contains antibodies. Antibodies are proteins produced by the body's immune (defense) system to fight infection." - According to https://www.google.bs/search?q=why+is+saliva+used+for+hiv+test&oq=why+is+saliva+used+for+hiv+test&aqs=chrome..69i57.7572j0j1&sourceid=chrome&ie=UTF-8
The antibodies help show is the virus is present since they are associated with the immune system and because this virus affects the immune system.(7 votes)
- At10:20he mentioned that you can't get infected by touching a toilet seat, but I have a question how long does it take for virus to die outside human body? Because if a woman is on menstruation and for example leaves a bit of blood on toilet seat are there no risk to get infected for the following woman who enters the toilet and has damaged skin?(4 votes)
While HIV can survive on surfaces, there are no known cases of people getting the disease from toliet seats, cleaning up patient's fluids, being spit on, mosquitoes bites etc. Needle sticks, where a health worker administers medication to an HIV patient and then accidentally sticks the needle into themselves can transmit the disease.. HIV has been around long enough that we have a good understanding of transmission. Other viruses, such as Ebola, more easily move by bodily fluids contact.(4 votes)
- Wait, so how exactly would people survive it? I have heard of some guy getting it and being cured but your can't believe everything you read(1 vote)
- Without treatment, HIV causes AIDS after approximately 10 years. The infections resulting from AIDS are what cause death (see the previous video in the series).
Before we developed antiretroviral therapy, essentially everyone that contracted HIV would eventually die of AIDS. However, modern therapies are highly effective and bring the viral load way down to a level at which the immune system functions normally. With a functional immune system, people can live a completely normal life IF they keep taking their medication.
There is not yet a cure for HIV. HIV can be controlled with medication but not eliminated completely because it forms a 'latent reservoir' integrated into host DNA. There are cases in which intense radiotherapy and chemotherapy for cancer patients has 'cured' their HIV temporarily by killing off their white blood cells completely, but that is an extremely rare scenario and not a therapy you would consider for someone without severe cancer.
A real cure would eliminate HIV from the body completely without killing off the entire white blood cell compartment. Lots of researchers are still working on this.(4 votes)
- Where is the semen and vaginal fluid formed?(2 votes)
- What are the symptoms of HIV(1 vote)
- A person with HIV often has no symptoms or mild flu-like symptoms. After 5 or more years, HIV destroys the immune system of the person and then they have trouble getting over simple infections. At this point they have AIDS, Acquired Immune Deficiency Syndrome. They might have a respiratory problem, a skin cancer, or any number of other problems because their immune system has been destroyed by the HIV virus. The only way to know a person has HIV is to get testing. Transmission is usually prevented with the use of condom protection during sex. Here is the CDC web site:
- can HIV travel though mosquito bites?(1 vote)
- No, HIV is not transmitted by mosquito bites, fly bites or any other insect. HIV is transmitted from one person to another person by sexual contact. HIV can be transmitted by on person using a syringe for drugs and then passing the syringe to another person and they use it. Please visit the CDC, a reputable source for these questions. https://www.cdc.gov/hiv/basics/transmission.html(1 vote)
- so why is there stigma about getting HIV? since the medications will help keeping almost everything under control.. like Hepatitis B... I understand the complications are very scary.. but still,,, !(1 vote)
- [Voiceover] So we know a little bit about HIV now. It's a virus that attacks your immune system, and if untreated, it will cause a state of immune failure, immune deficiency in a person, and that immune deficiency state is referred to as AIDS. It's essentially late stage of an untreated HIV infection. So I just wanna talk a little bit about some of the ways that HIV is transmitted, some of the different ways you can possibly get HIV into your bloodstream and, thus, develop an HIV infection. And let's actually do this in a bit of a simplistic way, because it turns out that HIV is most often transmitted through contact with three different types, I guess, of body fluid from an HIV-infected person. So, contact with their blood, with their sexual or genital fluid, and I'll expand on what that means in a minute or so, and from breast milk contact. And let's actually look at this in terms of four fairly common scenarios. These will be the most common situations that HIV is spread via these groups of fluid here. And let me just make it clear that these infected body fluids would need to come into contact with broken skin or directly with your bloodstream, maybe via an injection or something like that, or they'd have to come into contact with one of your mucous membranes, which are just parts of your body that aren't protected by normal skin. So, for example, inside your mouth or inside the vagina or the rectum or at the opening of the penis. HIV can cross into your body through these mucous membranes. You won't just become infected by, say, just looking at these fluids or just being near them or anything like that. One of these fluids would have to make it inside your bloodstream or make it through one of your mucous membranes by physical contact for you to possibly develop an infection, okay? So, top left up here, we'll make this sexual fluid contact, which is actually the most common way that HIV is spread, typically when having unprotected sexual intercourse with someone who has HIV. And don't let these pictures scare you. These are just cross-sections of pelvises. So, a female pelvis on the left here and a male pelvis on the right here. So we can use these to look at the sexual organs. So, contact with sexual fluids like semen or preseminal fluid or vaginal fluid or even rectal fluid can spread HIV because there's often a fairly high amount of viral particles within these fluids, particularly within the first few weeks of a new HIV infection, when the infected person's viral load in their blood or in their sexual fluids is up at extremely high levels. But in terms of actual sexual activities, in general, unprotected anal sex with either a man or a woman is the highest risk sexual behavior, because not only is there exposure of HIV-infected sexual fluids to mucous membranes, right, the opening at the tip of the penis and the inside of the rectum in a woman or a man are mucous membranes, but if there's any trauma to the involved body parts, there can be some blood there as well, and that might have virus in it, and, thus, increase the risk of infection. Virus from infected sexual fluid or blood can get across the mucous membranes of an uninfected person, or it can just get directly into a person's bloodstream through an area that might be bleeding. Now this is not to say that unprotected vaginal sex is not risky as well. It turns out that unprotected vaginal sex is the second highest risk sexual behavior because, again, there's exposure of sexual fluids, right, semen and vaginal fluid to mucous membranes, which HIV loves to hop across when it can. And again, there could be, although less likely than in anal sex, there could be trauma to the involved body part. So there can be some blood involved as well, of course, containing the HIV. And just so that I'm perfectly clear here, anal sex, I said, had the highest risk of transmission and vaginal sex the second highest risk, but vaginal sex is the way HIV is transmitted most frequently overall, because overall more people have vaginal sex over anal sex. And so, last in this sexual-themed quadrant, I just want to mention that oral sex of any kind, so using the mouth to stimulate the penis, the vagina, or the anus, carries a risk of transmitting HIV for much the same reasons as before. Mucous membranes of the mouth being exposed to sexual fluids and mucous membranes of the penis or the vagina or the anus being exposed to possibly blood, maybe the person's mouth had some open sores in it, which happens to be one of the symptoms that can happen in an HIV infection. And on that note, actually, having untreated sexually transmitted infections, like chlamydia or syphilis or herpes, vastly increases your risk of transmitting or becoming infected with HIV in risky scenarios, because you're more likely to have breaks in your skin or your mucosal surfaces from symptoms of these STIs, like sores or ulcers, and through these, HIV can more easily infect you. All right, next quadrant here. So, after sexual transmission, right, the most frequent mode of transmission, exposure to infected blood. So that's the next most frequent mode of transmission, and in particular procedures involving needles contaminated by someone else's blood. So, for example, using intravenous drugs and then sharing needles with an HIV-infected person. In that case, HIV is just one of the many viruses you might pick up by sharing needles in IV drug use, because you're essentially transferring tiny droplets of an infected person's blood directly into your bloodstream on a needle. Other needle or related procedures, needlestick injury. Let's say you're a healthcare worker, and you're working with an HIV-positive patient, right, maybe you're drawing some blood or something like that, you might accidentally get stuck by the needle after it's been contaminated with their blood, and this does occasionally happen, unfortunately. There's a risk of HIV transmission from them to you there, and remember to keep in mind that risk of transmission depends on some extent to a person's viral load. So these risks are all sort of modified to be higher or lower depending on how much HIV's in a person's blood. Typically, very low amounts of HIV, if they're being treated with specific medications, and typically pretty high amounts of HIV, if they're not being treated. Last thing I'll say here is contaminated blood transfusions, and this isn't so much of an issue these days, at least not in most countries, because of some seriously rigorous screening of donor blood and the blood supply that blood banks have on hand, but back in the olden days, you know, before the sort of late 80s, early 90s, donated blood was not routinely tested for HIV, as crazy as that sounds. So, contaminated transfusions don't happen very often these days in most countries, but worth a mention here because it's still something to be aware of. Now third quadrant, what's the third most frequent route of HIV transmission? Well, it's actually from an HIV-infected mom to her baby during childbirth. And kind of alarmingly, around 90% of the HIV that we see in kids, they actually got it in this way, from their mom during their birth, which is also called vertical transmission, mom to child during gestation or during birth. And we're not 100% sure how the transmission happens, but the thought is just because they're being exposed to mom's blood and vaginal fluid on the way out of the birth canal, and because they, well, newborn babies are essentially all mucous membrane at birth. They just have really thin skin. So it's not too hard for HIV to jump on board, so to speak. Luckily, there's all sorts of medications that we can give to mom before and after her pregnancy and labor, and there is medication that the baby can take as well, and all of that drastically reduces the risk of mom passing HIV on to her baby, from a risk of about 25 to 30% HIV transmission without medication, all the way down to only about 1 to 2% with medications, so around a 20-fold reduction in mom's chances of passing HIV on to her baby with the proper medication. Now, last quadrant. This one also involves mom and baby. It's transmission of HIV via breast-feeding. Breast milk in an infected mom will contain HIV particles. So when the baby feeds, it'll be ingesting lots and lots of HIV particles, which obviously mom is not intending. And it's not clear how the HIV gets into the breast milk in the first place, but when the baby ingests it, it can infect the baby by being absorbed through the digestive tract. So before we wrap up, I just want to briefly mention two things. So first, the risk of transmission, in at least this quadrant here, it goes way down if the infected person is using condoms to sort of physically block HIV transfer and also properly taking their HIV medication to reduce the viral load in their body, in their blood and the fluids that we mentioned in this scenario here. But also that second one, the properly taking the HIV medications, that will vastly reduce the risk of transmission in needle-sharing and in mom-to-newborn transmission and in breast milk, all of these scenarios here. The second thing is that these are all ways you can contract an HIV infection, but I think it's worth mentioning a few ways you can't contract an HIV infection that might not be well known, or there might be some myths around these. So unless any of these has been contaminated by infected blood, HIV is not transmitted by body fluids like saliva or tears or sweat or urine or feces, and it is not spread through the air, like say tuberculosis is. So being around people with HIV won't somehow transmit the virus through the air to cause an infection in another person. And it's not spread from casual contact either, say from shaking hands with or hugging someone who has HIV. It actually doesn't even survive very well outside a human body. So you can't become infected by sharing plates with an infected person in a restaurant or touching a toilet seat at a public restroom or anything like that. But there you go, the main routes of transmission, unprotected sexual activity, contaminated needles, from mom to newborn, and via breast milk.