[aleks224]

>An "elite controller" is a person living with HIV who is able to maintain undetectable viral loads for at least 12 months despite not having started antiretroviral therapy (ART) . Elite controllers are rare: for every two hundred people living with HIV, approximately one may be an elite controller (0.5%).

> It is not entirely understood why some patients are able to achieve undetectable viral loads without ART.

https://www.aidsmap.com/about-hiv/faq/what-elite-controller

[dillondoyle]

And undetectable === untransmittable. Just in case people here didn't know.

[raducu]

> And undetectable === untransmittable. Just in case people here didn't know.

In no way saying this is not a good thing, but do we know if this can be sustained for the whole lifetime?

Or is it that 20, 30 years later, as people get older the person eventually gets AIDS?

[est31]

As long as they take their daily ART pills, they are safe from AIDS in specific, which is basically a death sentence. But things are not black and white. Someone who has ever been HIV positive counts as immuno compromised for their entire life. Studies have shown that there is basically no shortening of life expectancy, if you start ART early enough in the process.

> if the person with HIV started ART with a CD4 count above 500, they would be expected to live to the age of 87 – a little longer than those without HIV.

https://www.aidsmap.com/news/mar-2020/yes-same-life-expectan...

[sterlind]

I've heard HIV patients describe ART as "aging" their organs. obviously preferable to dying horribly from AIDS, but still gnarly to contend with.

it's really interesting to me that their health becomes poorer earlier, but that it doesn't affect mortality.

[touisteur]

This might maybe be because a lot of effort is now poured on mid to end of life care, with the improving life expectancy? So the science behind pushing along a decaying body gets better?

[sterlind]

I sure hope so! I don't have HIV but I do have a genetic disorder that's wrecking my body. I'm determined to live as long as possible.

[hdjjhhvvhga]

I didn't know this. Could you explain the reason?

[matheusmoreira]

Viral load. Number of viral copies per volume of fluid.

Merely exposing someone to a virus does not necessarily result in widespread infection. A low enough number of copies could be neutralized by the host's immune response before it has a chance to spread significantly. How low this number is depends on the virus. For example, COVID-19 load is higher in symptomatic patients.

Chronic viral infections are managed by reducing as much as possible the number of viral copies in circulation. Risk of transmission is mitigated when number of copies is low enough. There are studies showing risk of HIV transmission approaches zero when HIV load < 200 copies/ml. Ideal would be HIV load < 50 copies/ml or undetectable.

https://en.wikipedia.org/wiki/Viral_load

https://en.wikipedia.org/wiki/Minimal_infective_dose

https://en.wikipedia.org/wiki/Management_of_HIV/AIDS

https://en.wikipedia.org/wiki/Viral_load_monitoring_for_HIV

[hashimotonomora]

At that low virion count it’s more about the probability that a virion will attach to the correct CD4 receptor and be able to work inside the cell. It’s not about the host's immune system defeating or being defeated on a number basis.

[est31]

To add to this, how many virions are needed for a successful replication to start depends on the virus.

https://www.virology.ws/2011/01/21/are-all-virus-particles-i...

[sampo]

There is an "independent action hypothesis" in virology. It states that each virus particle (virion) has an independent probability of starting the infection in the body.

https://royalsocietypublishing.org/doi/10.1098/rspb.2009.006...

[hdjjhhvvhga]

So it it turns out true, there is no "safe level" - we could talk about an extremely small probability, but it would still be higher than 0 - not exactly a risk one would like to take.

[sampo]

Yes. Assume 1 virion has a 0.001 chance to start an infection. You could infect 1 person with 692 virions, resulting in a 50% change of them getting ill (1-0.999^692). Or you could infect 692 people each with 1 virion, with 50% chance of at least 1 of them getting ill (35% chance: 1 ill, 12% chance: 2 ill, 3% chance: 3 ill, ...).

[Nbox9]

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-othe... https://www.nejm.org/doi/full/10.1056/NEJMoa1600693#t=articl... https://pubmed.ncbi.nlm.nih.gov/27404185/

[jl6]

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.

[vsef]

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.

[lixtra]

> 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]

Now that may be entirely the right posture, but the triple equals signs in the post upthread did rather imply certainty.

[hashimotonomora]

Risks like these are orthogonal and additive. There’s no reason to discard any risk but to hedge them.

[throwaway22032]

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.

[inglor_cz]

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/j...

[Terry_Roll]

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

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]

> 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.

Gay people were so stigmatized at the time that the government did nothing when they thought it was a 'gay disease'; they just let an epidemic spread and people die. Very few in the 1980s worried about offending gay people. Once it was spreading to people who weren't gay, then I'm sure health information was provided to those people.

[dillondoyle]

I'm not going to respond to a good chunk of this even though I'm itching too.

But I just have to laugh out loud at the thought of governments in the 80s not stigmatizing the disease and specifically queer people having anal sex.

Just so laughably the opposite of the real experience of an entire lost generation of gay men.

[hiptobecubic]

I had no idea "dry sex" was a thing. I am speechless. wtf?

[Terry_Roll]

Its like genital mutilation. These are legacy solutions when legacy forms of govt/social control like religions, royalty or cults were the main educational source for surviving back then. Ironically there still is some truth in things like religious fasting provided your glutathione levels are high enough.

There's no excuse for it in todays day and age, but what can you do? I sometimes think democracy is a soap opera for serious people, whilst the military run the real show.

[mlyle]

Some cultures believe lubrication is a sign of poor virtue or infidelity. Women use chalk, cornstarch, etc, to ensure they stay dry and to (supposedly) enhance the pleasure of their partner.

[ev1]

> 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.

You might find this interesting, the "few years back" might be now again: https://www.nature.com/articles/s41586-021-03901-9

[Terry_Roll]

Nothing would surprise me! I know a mad scientist who works at the UK's Porton Down, we discussed alot, but the systems are not in place to stop people shipping stuff around. Until such times as that happens, any country with the know how can release anything anywhere.

I think this Hollywood film Dont Look Up will be a poignant message to everyone.

[wolverine876]

> Some Sex lubes can make it easier for infections to get into the body. https://en.wikipedia.org/wiki/Personal_lubricant#Water-based

I would not use Wikipedia for health information with serious consequences.

[chucksmash]

Presumably the viral load required for transmission is greater than the viral load required for detection.

[whimsicalism]

My guess is it is more of a probabilistic thing than a strict threshold.

[staticassertion]

Yes. Super equals was inappropriate imo.

[whimsicalism]

I don't know that it's inappropriate.

I mean, technically, there's always a possibility of getting HIV. Particles in your body could spontaneously quantum tunnel at the same time into the form of an HIV virus. This is basically impossible, but not actually (p = 0.00) impossible.

At some point you have to look at a probability and say - that's basically not transmissible.

[dillondoyle]

I mean just based on the definition that seems like the literal meaning to me. But i'm not a PHD

[stjohnswarts]

That seems like a big if? maybe 0.5% of people actually are succeptable to the lowered viral load. Have studies been done that would detect such a population?

[mlyle]

One reason we believe this is that we can typically detect virus quantities way too small to reliably replicate in culture, and believe that in vivo infection is even harder than in culture (because of innate immune response and the body not being composed just of the most susceptible cells).

You generally can't measure infectious dose directly without a highly unethical challenge study. You can sometimes know concentrations that did or didn't result in infection in various real world scenarios, and sometimes you have circumstantial evidence (e.g. you can know how much virus a person sheds, and what proportion of a room with certain ventilation quantities got infected).

[makomk]

The usual way of achieving undetectable viral load is via anti-retroviral drugs and I think this works in most people, at least so long as they get early enough treatment and keep getting it. The main reason to measure viral load in the first place is to get an idea of how well the drugs are working and if they need to be changed.

[scaredginger]

People on ART also often (perhaps usually) have undetectable viral loads

[jxramos]

that's what I would think, it's got to be quantifiable: some sensitivity metric of the concentration of virus particles the device can detect vs the minimum quantity which is needed for infection. It's clear we can articulate these matters in the abstract, how does one go about actually measuring such a thing?

[inasio]

Undetectable sometimes means less than 200 or less than 50 viral copies per ml (depending on device sensitivity). In contrast the peak in the acute phase is 10^7 copies per ml (and settles to around 10^5 in the chronic phase), the probability of transmission is infinitesimal. There are many studies following very high risk cohorts (sex workers, intravenous drug users, etc) that have been able to empirically confirm this.

[astura]

https://www.hiv.gov/blog/science-validates-undetectable-untr...

[baq]

No detectable virus means no transmissible virus.

[Drdrdrq]

To reiterate the question, why is that?

[JulianMorrison]

Detection means there is enough virus physically present in the sample for the detection technology to identify it.

Infection requires virus particles to be physically present in transmission vectors (fluids, droplets, etc). There's generally also a dose-response effect where more particles means more chance of evading the immune system well enough to establish replication in the victim.

So a lack of anything to detect, means a lack of anything to spread an infection.

[_Microft]

> So a lack of anything to detect, means a lack of anything to spread an infection.

One should add that for that the threshold for detection has to be lower than the threshold for infection.

Example: let the detection threshold be 10 particles/ml and the infection threshold be 100 particles/ml (*) -> then undetectable implies that it is very improbable that an infection will take place.

(*) This is a very crude description. Think of it like this: Every single virion (virus particle) has a very low probability of causing an infection itself but there is a high number of them and for one them it might just work out (higher viral load -> higher risk of successful infection)

[Drdrdrq]

Thank you, makes sense!

[space_fountain]

I'm not a biologist and this is based on general knowledge and some quick google searches but:

We're quite good at detecting viruses if we really want to. PCR can amplify DNA so much that we can detect even 50 viruses per milliliter of blood. A milliliter seems like actually a lot of blood to get into someone else and your innate immune system is capable of finding and neutralizing small amounts of contagions relatively well even if it's never seen it before. I do suspect this is a statistical impossibility though probably you could somehow get incredibly unlucky, for example in your blood momentarily all the free floating viruses end up in the same bit of blood and that somehow gets into someone else, but I think we can all realize that probability is tiny and in practice I don't think there are any examples of transmission with undetectable levels of HIV.

[et2o]

Well put. We can actually detect well below 50 copies/mL in the laboratory setting as well; we don’t go below this to maintain adequate test specificity and sensitivity in the clinical setting.

[jagger27]

> A milliliter seems like actually a lot of blood to get into someone else

1 cm^3 is indeed pretty big. That’s 1,000 little millimetre cubes, and we can detect as few as 50 virions in that space!

I will point out though that 1 ml is low for semen (more like 2.5 ml or more).

[XzAeRosho]

That's the million dollar question

[hashimotonomora]

False. Detectable is an experimental limitation of a given measurement system. Even one single virion can infect a host.

[et2o]

There is no data that supports this assertion whatsoever. There is a lot of evidence going against it. Theoretically it may be possible, but the probability of this is on the order of 0 and so close to 0 it will likely never happen.

Think of it like chemistry. Sure, two covalently bonded hydrogen atoms at STP could have nuclei 1cm from each other due to random chance. However, the probability of this happening is so low that it is effectively 0.

[hashimotonomora]

The assertion is still false then.

[mensetmanusman]

It depends on if your body is able to detect it better than a machine…

[mariodiana]

I'm going from memory, and I can't remember how many years ago I saw this on television, but I thought it had something to do with a genetic mutation that likely gained a foothold in the Western European population sometime around the plague of the Middle Ages. If I remember correctly, if a person carried one copy of the gene, they could get infected with HIV, but it wouldn't develop into AIDS. If a person carried two copies, they would not even get infected with HIV.

Anybody remember hearing something like this?