11 ms·

CDC backing up this claim. Having an undetectable viral load prevents transmission during sex —- but likely not during needle sharing. The answer to why seems

by Nbox9 5y ago

CDC backing up this claim. Having an undetectable viral load prevents transmission during sex —- but likely not during needle sharing. The answer to why seems to be an obvious “because there are less virus particles”. I’m linking a couple of scientific studies following couples having condomless sex where one partner is HIV positive, on ART with low viral load. Among the about 2000 couples in these studies there were no transmissions. https://www.cdc.gov/hiv/basics/livingwithhiv/protecting-others.html https://www.cdc.gov/hiv/basics/livingwithhiv/protecting-othe... https://www.nejm.org/doi/full/10.1056/NEJMoa1600693#t=article https://www.nejm.org/doi/full/10.1056/NEJMoa1600693#t=articl... https://pubmed.ncbi.nlm.nih.gov/27404185/ https://pubmed.ncbi.nlm.nih.gov/27404185/

jl6 5y ago
It does sound suspiciously like wishful thinking though, doesn’t it? You can’t sample all parts and all fluids of someone’s body all the time. Maybe trace undetectable levels of the virus can be transmitted, and of course they are going to look like a “no transmission” case if you lack the ability to detect that amount of virus. And that’s either not a problem (if trace levels = no symptoms), or a ticking time bomb waiting to find a host with the conditions that would enable mass viral replication back up to detectable levels.
- throwaway22032 5y ago
  We feel fairly comfortable in stating that HIV is not transmissible surface-to-surface despite the mathematical fact that strictly there is some miniscule non-zero chance that it could be, this is basically the same thing.
- lixtra 5y ago
  > You can’t sample all parts and all fluids of someone’s body all the time. Maybe trace undetectable levels of the virus can be transmitted… You don’t need to be a 100% sure. Once the risk becomes small enough you can spend your time worrying about other risks.
  - jl6 5y ago
    Now that may be entirely the right posture, but the triple equals signs in the post upthread did rather imply certainty.
    - whimsicalism 5y ago
      The standard you are applying is literally not possible to imply anywhere. Hell, an HIV viron could be created spontaneously through quantum tunneling in your body with some non-zero probability. I think it would be legitimate to triple equal signs that to "not going to happen" though.
    - austhrow743 5y ago
      I took that to just be because we’re on a programmer heavy site rather than an extreme display of certainty
  - hashimotonomora 5y ago
    Risks like these are orthogonal and additive. There’s no reason to discard any risk but to hedge them.
    - tomp 5y ago
      Activity-based risks are not additive. Time spent driving is not time spent having sex (well, hopefully). So if risk(dying while driving) ~ risk(dying because of sex) ~ 0, you can easily ignore both of those.
      - dtgriscom 5y ago
        risk(dying while (driving while having sex)) >> 0...
      - hashimotonomora 5y ago
        Be careful. The infinite sum of epsilons over an infinite domain and over the time domain can and usually does converge to a finite value in real life. Also, you can avoid having sex with a HIV-positive person. You can probably not avoid driving. So the fact that a risk may be low is not sufficient to take such risk if you can hedge against it.
- vsef 5y ago
  There is no such thing as a trace/undetectable transmission. These studies have been going on a long time now with large numbers of participants, replicated in multiple countries/different populations. The results are very strong and not based on measuring viral levels.
- inglor_cz 5y ago
  You need to transmit a certain amount of HIV particles to cause infection. It is called inoculum. In normal sex, it is quite a lot, I wasn't able to find an exact number, but it is in tens of thousands in ther least. The vast majority of virions seems to be killed by the immune system before they can actually take hold. https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006313 https://journals.plos.org/plospathogens/article?id=10.1371/j...
Terry_Roll 5y ago
So some other points. Some Sex lubes can make it easier for infections to get into the body. https://en.wikipedia.org/wiki/Personal_lubricant#Water-based https://en.wikipedia.org/wiki/Personal_lubricant#Water-based Thing is I wonder if a higher vitamin A and zinc intake can help because all epithelial cells need retinol (vitamin A), zinc is needed to move retinol around the body as Retinol Binding Protein (RBP) for epithelial cells. Alcohol can reduce fat soluble vitamins stored in the liver which can then reduce the VitA stored in the liver, you see this most easily with alcoholics and hypovitaminosis A, but even short term binge drinking can reduce levels enough to increase risks of transmission which probably explains man flu! I found a cadaver study where they measured vitA content in the livers of dead people but didnt say how they died, knowing that you can die from ingesting too much vitA in one go like some arctic explorers did when eating polar bear livers decades ago and died. In order to get the highest amounts of vitA seen in some of these cadavers, you'd have to consume 30,000ui of VitA every day for at least a year without your body using any! Thats a lot of Vit A!!! Anyone who paid attention to the Ebola outbreak in Africa a few years back, may remember that some viruses like Ebola can hide in parts of the body where the immune system can not go, namely the eyes and the testes and sometimes the brain, so they may have remembered that blokes testing negative for Ebola but previously had it, could still be passing it on through semen. The thing with HIV, its typically passed through anal intercourse, not vaginal where there is sufficient lubrication, but its passed more frequently in Africa because they have a tendancy to have dry vaginal intercourse, because they actually try to reduce the wetness of the vagina which then creates microtears and sores and then its easy for HIV to get into the bloodstream, just like cuts and sores in the mouth also making it easy for HIV to get into the blood. The whole 80's govt advice/warnings on HIV were directed at everyone because they didnt want to stigmatise those engaging in non vaginal intercourse. The biggest risk from HIV is getting it into the blood, like most things which are pathogenic. Now you can still have a highly effective immune system which can lock down viruses, but there is always the risk it gets into those parts of a body where the immune system cant go and I dont know what they test now a days.
- wolverine876 5y ago
  > Some Sex lubes can make it easier for infections to get into the body. https://en.wikipedia.org/wiki/Personal_lubricant#Water-based https://en.wikipedia.org/wiki/Personal_lubricant#Water-based I would not use Wikipedia for health information with serious consequences.

by Nbox9 5y ago

jl6 5y ago

It does sound suspiciously like wishful thinking though, doesn’t it? You can’t sample all parts and all fluids of someone’s body all the time. Maybe trace undetectable levels of the virus can be transmitted, and of course they are going to look like a “no transmission” case if you lack the ability to detect that amount of virus. And that’s either not a problem (if trace levels = no symptoms), or a ticking time bomb waiting to find a host with the conditions that would enable mass viral replication back up to detectable levels.

throwaway22032 5y ago
We feel fairly comfortable in stating that HIV is not transmissible surface-to-surface despite the mathematical fact that strictly there is some miniscule non-zero chance that it could be, this is basically the same thing.
lixtra 5y ago
> You can’t sample all parts and all fluids of someone’s body all the time. Maybe trace undetectable levels of the virus can be transmitted… You don’t need to be a 100% sure. Once the risk becomes small enough you can spend your time worrying about other risks.
- jl6 5y ago
  Now that may be entirely the right posture, but the triple equals signs in the post upthread did rather imply certainty.
  - whimsicalism 5y ago
    The standard you are applying is literally not possible to imply anywhere. Hell, an HIV viron could be created spontaneously through quantum tunneling in your body with some non-zero probability. I think it would be legitimate to triple equal signs that to "not going to happen" though.
  - austhrow743 5y ago
    I took that to just be because we’re on a programmer heavy site rather than an extreme display of certainty
- hashimotonomora 5y ago
  Risks like these are orthogonal and additive. There’s no reason to discard any risk but to hedge them.
  - tomp 5y ago
    Activity-based risks are not additive. Time spent driving is not time spent having sex (well, hopefully). So if risk(dying while driving) ~ risk(dying because of sex) ~ 0, you can easily ignore both of those.
    - dtgriscom 5y ago
      risk(dying while (driving while having sex)) >> 0...
    - hashimotonomora 5y ago
      Be careful. The infinite sum of epsilons over an infinite domain and over the time domain can and usually does converge to a finite value in real life. Also, you can avoid having sex with a HIV-positive person. You can probably not avoid driving. So the fact that a risk may be low is not sufficient to take such risk if you can hedge against it.
vsef 5y ago
There is no such thing as a trace/undetectable transmission. These studies have been going on a long time now with large numbers of participants, replicated in multiple countries/different populations. The results are very strong and not based on measuring viral levels.
inglor_cz 5y ago
You need to transmit a certain amount of HIV particles to cause infection. It is called inoculum. In normal sex, it is quite a lot, I wasn't able to find an exact number, but it is in tens of thousands in ther least. The vast majority of virions seems to be killed by the immune system before they can actually take hold. https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006313 https://journals.plos.org/plospathogens/article?id=10.1371/j...

Terry_Roll 5y ago

So some other points. Some Sex lubes can make it easier for infections to get into the body. https://en.wikipedia.org/wiki/Personal_lubricant#Water-based https://en.wikipedia.org/wiki/Personal_lubricant#Water-based Thing is I wonder if a higher vitamin A and zinc intake can help because all epithelial cells need retinol (vitamin A), zinc is needed to move retinol around the body as Retinol Binding Protein (RBP) for epithelial cells. Alcohol can reduce fat soluble vitamins stored in the liver which can then reduce the VitA stored in the liver, you see this most easily with alcoholics and hypovitaminosis A, but even short term binge drinking can reduce levels enough to increase risks of transmission which probably explains man flu! I found a cadaver study where they measured vitA content in the livers of dead people but didnt say how they died, knowing that you can die from ingesting too much vitA in one go like some arctic explorers did when eating polar bear livers decades ago and died. In order to get the highest amounts of vitA seen in some of these cadavers, you'd have to consume 30,000ui of VitA every day for at least a year without your body using any! Thats a lot of Vit A!!! Anyone who paid attention to the Ebola outbreak in Africa a few years back, may remember that some viruses like Ebola can hide in parts of the body where the immune system can not go, namely the eyes and the testes and sometimes the brain, so they may have remembered that blokes testing negative for Ebola but previously had it, could still be passing it on through semen. The thing with HIV, its typically passed through anal intercourse, not vaginal where there is sufficient lubrication, but its passed more frequently in Africa because they have a tendancy to have dry vaginal intercourse, because they actually try to reduce the wetness of the vagina which then creates microtears and sores and then its easy for HIV to get into the bloodstream, just like cuts and sores in the mouth also making it easy for HIV to get into the blood. The whole 80's govt advice/warnings on HIV were directed at everyone because they didnt want to stigmatise those engaging in non vaginal intercourse. The biggest risk from HIV is getting it into the blood, like most things which are pathogenic. Now you can still have a highly effective immune system which can lock down viruses, but there is always the risk it gets into those parts of a body where the immune system cant go and I dont know what they test now a days.

wolverine876 5y ago
> Some Sex lubes can make it easier for infections to get into the body. https://en.wikipedia.org/wiki/Personal_lubricant#Water-based https://en.wikipedia.org/wiki/Personal_lubricant#Water-based I would not use Wikipedia for health information with serious consequences.