I just saw a recent report about a meta-study on HIV transmission rates that I thought was worth sharing:

"As expected, sexual exposure risks ranged from too low to quantify for oral sex, to 138 per 10,000 for receptive anal sex. Falling in between were insertive anal sex (11 per 10,000), receptive vaginal sex (8 per 10,000), and insertive vaginal sex (4 per 10,000).

Over ten years, using no prevention measures at all, the risk of transmission via vaginal sex for a heterosexual couple with an HIV-positive woman was estimated to be 44%. For gay male couples, the estimated ten-year risk reached nearly 100%. A substantial cumulative risk remained for couples using any single prevention strategy, the researchers concluded.
Based on risk reduction levels seen in prior studies, as described above, the researchers calculated that for a heterosexual couple using only condoms for vaginal sex, the transmission risk over ten years was 11%."

Here is the full article:  http://betablog.org/studies-shed ... isk-and-prevention/

Essentially, what it says (that is most important to us) is that while HIV transmission from an infected-female to a male via standard vagina intercourse is extrremely low (4 per 10,000) (as we already knew).  BUT:  over time, the numbers creep up.   The iikelihood of a man becoming infected by an infected female spouse thru normal (non-anal) intercourse rises to over 40% without condom use after 10 years.  And even as high as 11% WITH regular condom use.

So, what this tells me:  If you regularly engage in unprotected sex, even if you practice only vagina intercourse, the risks of eventually contracting HIV remain significant.

Suit-up, Bros!

Interesting.  Thanks for sharing.  Given that anyone of us has an average couple's decade's worth of sex in a single month, perhaps we really should be careful base on this paper.   

As a scientist, though, I question some of the conclusions.  It's tough to judge a meta analysis because it depends upon the studies it's analysing.  Some of the underlying studies have insignificant populations, which leads to wild data.  In the aggregate, like in a meta analysis, it's misleading.  Also, I don't know for sure because I haven't audited each study but I would gather that the underlying research teams could not guarantee or confirm that the HIV-negative partner did not engage in other risky behaviours.  Not to be judgemental but in couples where one partner is HIV positive, I would guess that both partners engage in higher risk activities than your average HIV negative couple which could explain the increased infection rate over time.

If you're just speaking about the statistics and the math without the human bavioural distortions, a .0004 percent chance of infection per incident of vaginal intercourse is .0004 each time.  It doesn't accumulate. Each instance has its own odds.  Like playing the lottery.  You don't increase your chance of winning by buying 5 tickets. Each ticket has the same odds of winning--163,472,874:1 or something in that neighbourhood.

Anyway, I think HIV is the least of our worries because there are much more efficient STIs that we can catch and which can make one pretty unhappy.  Condoms are just a requirement.  Full stop.  

Play safe bros.

[ Last edited by  biardker at 28-5-2015 00:18 ]

Well, in your lottery example you DO increase your chance of winning, just not by very much:  your odds go from 163,000,000:1 to 163,00,000:5.  The odds of each ticket doesnt change, but you bought more of them so your overall odds of winning have increased.  It is additive.   

And this is what the study is saying, actually:   After 10 years of banging this gal unprotected (not sure how many times per year they used as a baseline) your odds that one of those sexual events transmitted the HIV virus from her to you is 40%.  And even 11% WITH condom use.  

That said... from reading the full article it seems like a decently done study as far as weeding out the outliers... EXCEPT for behaviors one might often lie about even in such a study (other risky behaviors:  drug use, cheating unprotected or with anal, etc. etc.).   

Perhaps it is JUST these (common) deviant (hehe) behaviors that increase the likeliness of getting HIV.  Possible.

I recall the entire fear of an extreme AIDS epidemic in the 80s was mostly caused by HIV-positive men lying about the fact that they were either intravenous drug users, or took part in gay anal-sex. They wouldnt admit to these behaviours and so all the studies were very skewed - indicating much higher transmission rates for straight non-drug-using men than it really was.  Once these deviations were accounted for the "true" HIV transmission rate from woman to man turned out to be very, very small.

Interesting information.

As discussed above, I always take any "sex centric" studies with a large grain of salt.

Think how many of us, if asked would answer honestly about our number of partners. I suspect it would be very few of us that would, heck, even fewer that actually could out a number to it.

Then if you look at population samples, the number of punters that are active in the hobby with same sex partners is higher than would be openly reported. Ladyboys/TS/TV, whatever term you choose.

Lastly, the biggest lie in punting, "I always use protection!". I am not saying there aren't exceptions within our community, the oaks among us if you will. I'm just saying that the more you punt, the more instances where you encounter some SYT pulling your uncovered cock into their wet, hot, tight, little pussy.

Taking all of these things into consideration, I will stick with my attempts to play safe, be choosy, and never punt in Sub-Sharan Africa with a 6'3" "girl" that only wants me to give it to her bareback up the arse.

Sorry.  It's not additive. It's a factorial.  Anyway, doesn't matter.  I think the study results are weird and perhaps the result of outside distortions. That said, condom use is a must.

Sorry.  It's not additive. It's a factorial.  Anyway, doesn't matter.  I think the study results are weird and perhaps the result of outside distortions. That said, condom use is a must.

Good news.   At last I have mathematical vindication for my own perv:  DATY.  To quote the OP "sexual exposure risks ranged from too low to quantify for oral sex".  Now I can sleep at night and continue making my favorite WG's happy with my mouth. . . .

Yep. Sure as I am that rolling a pair of dice a hundred times doesn't change the odds of rolling two 6s.

Yep. Sure as I am that rolling a pair of dice a hundred times doesn't change the odds of rolling two 6s.

I am not a scientist but:

Over the course of ten years the viral load of the infected partner would inevitably increase， giving an increased risk factor.

Now there's an explanation but one that isn't detailed in the meta analysis. Along the lines of our collective guess that serodiscordant couples probably enagage in higher risk behaviours (on balance) that HIV negative couples. Lots of possible explanation but increased incidents--without more--isn't one of them.

There's a bit of politics here as well. American medical studies are often rife with political slant unfortunately.  Even protected sex carries an increased risk over time. Message: continue to take HIV seriously because the trends show people are no longer taking HIV seriously in America and secondly, only God fearing abstinence can save you for sure.  

Thank you Dr. Jim Bob.

Now there's an explanation but one that isn't detailed in the meta analysis. Along the lines of our collective guess that serodiscordant couples probably enagage in higher risk behaviours (on balance) that HIV negative couples. Lots of possible explanation but increased incidents--without more--isn't one of them.

There's a bit of politics here as well. American medical studies are often rife with political slant unfortunately.  Even protected sex carries an increased risk over time. Message: continue to take HIV seriously because the trends show people are no longer taking HIV seriously in America and secondly, only God fearing abstinence can save you for sure.  

Thank you Dr. Jim Bob.

Now there's an explanation but one that isn't detailed in the meta analysis. Along the lines of our collective guess that serodiscordant couples probably enagage in higher risk behaviours (on balance) that HIV negative couples. Lots of possible explanation but increased incidents--without more--isn't one of them.

There's a bit of politics here as well. American medical studies are often rife with political slant unfortunately.  Even protected sex carries an increased risk over time. Message: continue to take HIV seriously because the trends show people are no longer taking HIV seriously in America and secondly, only God fearing abstinence can save you for sure.  

Thank you Dr. Jim Bob.

Okay Biardker, let's try it this way:

You flip a coin 100 times.  What are the odds that AT LEAST ONE of those 100 times lands on a head?

If you tell me 50/50 than I give up trying.

Yes, it remains a 50/50 probability on EACH INDIVIDUAL toss, but the probability that AT LEAST ONE of the tosses was a head grows each time.  It would near 100% at 100 tosses.

Haha! Classic!

I think it is quite simple "The more you fuck the greater the risk" the same as "The more you fly the greater the risk"

Obe

Odds of heads after one flip is 50%

Odds of heads after two flips is NOT 50%+50% ... that would be 100%, which you can disprove with a simple experiment!  

You have to multiply the odds of successive attempts:  the chance of getting heads after two flips is the chance of getting it on the first flip plus the chance of NOT getting it of the first AND getting it on the second (which involves two probabilities).  i.e. 50% + 50%x50% = 75%

A homework exercise for the student would be to figure the probability of getting heads on exactly the third throw ... any takers??

Having said that the odds of getting the lottery after buying one ticket on five successive draws is actually pretty close to 5x the odds of winning on one ticket, simply because the odds of not winning are so close to 1 that the error is very small.  That means you're also right to an engineering approximation in your example.  

But he's still right the probabilities don't merely add together!  

The odds of you getting HIV from the NEXT girl you BB is the same as the odds of getting it from the LAST girl you did (all other considerations being equal eg assuming they had the same number of past partners, and the same degree of risky partners, etc)

But the odds of you getting HIV from ONE OF the next 20 girls you BB is much higher.  

Totally agree nobody can afford to be complacent

And going BB is not just risky for yourself, it's irresponsible for the entire community, of girls and their clients and their families.

Yeah, I used the word "additive" to imply the overall odds of an event occurring increase with successive attempts -- eventually approaching 100%.  But my math schooling was sooooo bloody long ago I dont doubt it is the wrong word.

Anyway, your 2-coin-toss example is good...  a 75% probability of flipping at least one head over 2 tries;   87.5% after 3 tries; 93.75% after 4 tries.  Etc, etc. etc.....  never actually hitting 100% but quickly becomes infinitely close.

It actually increases like this, we will say heads is our choice for each toss. Expecting we always use a fair coin then the chances of heads after the first toss is 1/2. After the second it is 1/4, then 1/8, 1/16, and on the fifth toss you are setting at 1/32 chance of the toss coming up heads.

However, the the coin has no knowledge of previous tosses so it will always be 50/50 for that individual try. If this seems wrong I would refer you to the gambler 's fallacy or also known as the fallacy of the maturity of chances.

Bottom line is that I did go to public schools, but this is just basic math and I could be wrong.

[ Last edited by  jake.houston at 30-5-2015 03:50 ]

I was looking at this site  http://math.stackexchange.com/qu ... have-a-49-95-chance

The question on the site was what are the odds of losing 20 times in a row when the probability of winning is 49.95%.  The answer given was the formula:

(1-Probability of winning)^number of games played

Using the formula in our situation
Odds of emerging unscathed = (1-Odds of catching)^Number of punts with an infected partner

If this is the correct formula, and the odds are 8/10000
So daily sex for one year with an infected spouse would give you a 74.6% chance of staying clean
Daily sex for 10 years gives you only a 5% chance of never 'winning'.

This is only a pure mathematical answer though that could not be expected to predict reality.  Reality is a lot different as risk would be changed by a multitude of other variables and confounds.  Using math like this to make real world decisions would be like doing a cliff walk blindfolded, guided only by your GPS.

Also, winning or losing at roulette or lottery - you are the only loser.  That is not the case with unsafe flying, driving, cooking, or sex.

[ Last edited by  yazoo at 29-5-2015 16:37 ]

But what are the odds that 10 pieces of tail in a row will give you head?

Gherk