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.

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.

> 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.

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

I took that to just be because we’re on a programmer heavy site rather than an extreme display of certainty

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.

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

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.

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.

It is because everyone dies relatively quickly that you can ignore ultra low risks. Suppose your lifespan was potentially 1 trillion years, how low would your risk tolerance need to be?

Meanwhile doing some once a day with a 1 in 1,000,000,000 chance of possibility killing you in 40 years just isn’t worth considering.

> Suppose your lifespan was potentially 1 trillion years, how low would your risk tolerance need to be?

Depends what your quality lifespan is. If I get sick of everything, that time isn't worth much.

There's also a "time-value" of life.

Cool stuff I can do today may be worth a lot more to me than things I can do 500B years from now. Especially since the person that would be doing them is someone I cannot identify with at all.

I don’t think most peoples 25 year old self can really identify what their 85 year old self will be like. Yet saving for retirement isn’t just about them some time in the future it’s about making you feel better now.

> I don’t think most peoples 25 year old self can really identify what their 85 year old self will be like.

Yes, and I believe this is a reason why people make choices that adversely affect their 50 year old self. Who's that guy in the future going to be? Why should I care about making it better for him?

You could say the same thing about people drinking heavily only to wake up the next day with a massive hangover. So it isn’t the differences between them that’s causing people to screw over their future self.

I can't comprehend 1000-year-from-now me. I don't think I would take many actions to improve life for 1000-year-from-now me even if I knew I could live millennia. Doing so does not buy me any comfort today and does not let me "give" to any person that I identify with or recognize as part of me.

I can imagine time scales on a par with how long I've lived and to a lesser extent to the ages of people I identify with.

(500 year from now me would see the first paragraph as exceptionally foolish... and also inevitable. But that fact doesn't change the truth of what I'm saying).

risk(dying while (driving while having sex)) >> 0...

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.

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...

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.

> 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.

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.

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

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.

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.

It makes zero sense, but yeah.

There was a thing not long ago where talcum powder, I think Johnson & Johnson, had some asbestos contamination (asbestos being another mineral that can come from the same mines, apparently). And people were suing because it gave them cancer of the uterus and other internal parts of the female reproductive system. Which makes you go: Wait a second. How the hell does that happen?

That's how.

I find it hard to believe. Wouldn't it make more sense that the powder was in contact with the external reproductive parts for extended amounts of time (which is its normal usage) and as a result some parts managed to get inside?

I don't think people are intentionally pushing talc through their cervix, if that's what you mean. But, pack your vagina with the stuff every day, and I imagine you can have all kinds of problems. If I were to go any further than that about exactly how it works I'd be speculating.

OK, I see. Because back in the day it was more or less standard to use powder in the groin area and leave it for hours in order to prevent skin irritation in babies, especially in the summer. So since it was standard usage, people should reasonably expect that the powder sold for this purpose was sufficiently examined and fit for the purpose.

When I first heard about asbestos in children talc powder, I simply thought it was just one of these "bad pharma" conspiracy theories (there was another one - about asbestos in sanitary towels). It seemed so far-fetched - who in their right mind wouldn't make sure to thoroughly check a product designed to have long-term contact with babies' skin against well-known carcinogenic substance? Well, it turns out this time it happened not in China but right in the heart of the USA.

> 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

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.

> 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.