The HIV Paradox: A Tale of Two Males

[CallMeIshmael]

Meet two guys: Jordan and Jason.

Jordan: Jordan is a successful good looking guy, and has managed to find himself a great wife: Sarah. They've talked about their past sexual history. Sarah is not a virgin, but she isnt a whore either. But, she has never been tested. Jordan would consider her less likely to have HIV than a member of the US adult population picked at random (that number is 0.6% ( source (http://www.cia.gov/cia/publications/factbook/geos/us.html))). He is willing to cut that number in half, to 0.3%. Sarah is on the pill, and when she and Jordan have sex, he doesnt wear a condom. He estimates they will have sex 15 times per month over the course of the next year. (180 times in total) He will never have sex with another female, nor is he an IV drug user.

Jason: Jason doesnt have a girlfriend. His sexual encounters over the next year will all be one night stands. He estimates he will have sex 20 times. These women are not overly 'clean', as Jason isnt of discriminating taste. He estimates that each women is twice as likely to have HIV than an average adult (1.2%). On top of that, he tends to visit a prostitute every two months, for a total of 6 for the year. It is estimated that 4% of prositutes in the LA area have HIV (source (http://answers.google.com/answers/threadview?id=370242)) Jason doesnt like the way condoms feel, and never wears them. He is also not an IV drug user.


We can calculate the probability of both Jordan and Jason contracting HIV over the course of the next year.

The probability of someone contracting HIV through unprotected sex with an HIV-postitve partner is 0.002 (This is the upper bound, taken from source (http://www.cirp.org/library/disease/HIV/gray2/))

Jordan: He is in an 'Either/Or' situation. If Sarah doesnt have HIV, then he will never contract HIV over that year. IF she is, however, the probability of him contracting HIV =

1 - (499/500)^180 = 0.3026

Since, Jordan estimates the probability of Sarah having HIV is 0.3%, his final chance of contracting is:

= 0.0907%


Jason: His equation looks like:

1 - P(Getting HIV)

= 1 -

(1 - (1.2/100*1/500))^20*(1-(4/100)*(1/500))^6

= 0.0959%


These two are about equally likely to contract HIV over the next year.


EDIT: Since this seems SO counterintuitive, there is a decent chance I messed up the math somewhere. Can anyone verify that I did the math right? It seems right.

[pudley4]

[ QUOTE ]
He estimates they will have sex 15 times per month over the course of the next year.

[/ QUOTE ]

Spoken like a true unmarried man.

BAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!

[istewart]

[ QUOTE ]
'Either/Or'

[/ QUOTE ]

Gay Elliott Smith reference?

[CallMeIshmael]

[ QUOTE ]
Spoken like a true unmarried man.

BAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!

[/ QUOTE ]

/images/graemlins/grin.gif /images/graemlins/grin.gif /images/graemlins/grin.gif /images/graemlins/grin.gif

[Tron]

This is interesting.

Jason probably has the clap, and herpes, and syphilis, and crabs, and warts, and other bad things, though.

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
'Either/Or'

[/ QUOTE ]
Elliott Smith reference?

[/ QUOTE ]

Yes.

[mason55]

So I can [censored] random women without a condom, including hookers, and I won't get the HIV? SWEET!!!!

Truthfully, we all know AIDS was invented by the govt and got out of control. They give the cure to people who aren't gay or minorities. They invented crack to kill minorities but realized they needed the gays too, so they made AIDS. No straight white male will die of AIDS.

[Emmitt2222]

interesting choice of names...

[Talk2BigSteve]

[ QUOTE ]
This is interesting.

Jason probably has the clap, and herpes, and syphilis, and crabs, and warts, and other bad things, though.

[/ QUOTE ]

LOL you beat me to it! I was going to say he may not have the big one, but he is covered in Crotch Crickets

Steve

[Tron]

[ QUOTE ]
Crotch Crickets

[/ QUOTE ]

That phrase is disgusting. Congratulations.

[Voltron87]

[ QUOTE ]
So I can [censored] random women without a condom, including hookers, and I won't get the HIV? SWEET!!!

[/ QUOTE ]


high five, dude. the cops wont hassle us either.

"did you see who stole that car?"
"uh, sort of, I wasn't able to see his face but I could tell he was puerto rican"

problem solved.

[shant]

I think you meant strippers, not prostitutes.

[Talk2BigSteve]

[ QUOTE ]
[ QUOTE ]
Crotch Crickets

[/ QUOTE ]

That phrase is disgusting. Congratulations.

[/ QUOTE ]

Welcome to Word Heard From Rednecks 101.

Steve

[BigBaitsim (milo)]

150 times a year. Not a married guy, clearly.

[CallMeIshmael]

[ QUOTE ]
I think you meant strippers, not prostitutes.

[/ QUOTE ]

HAHAHAH


FWIW, this idea started along the lines of:

Dear Bison,

What are the chances Jason_t is bring some friends home from Vegas?



Then, I remembered that I read about this 'paradox' once, and decided to go this way.


Its interesting, because, for the most part, people mention the safeness of the partner far more than the frequency of the act when discussing the chances of HIV contraction.

[CallMeIshmael]

[ QUOTE ]
interesting choice of names...

[/ QUOTE ]


Really? How so? /images/graemlins/tongue.gif

[gumpzilla]

[ QUOTE ]

Its interesting, because, for the most part, people mention the safeness of the partner far more than the frequency of the act when discussing the chances of HIV contraction.

[/ QUOTE ]

For a sufficiently safe partner, the frequency of the act will become irrelevant.

[CallMeIshmael]

[ QUOTE ]
For a sufficiently safe partner, the frequency of the act will become irrelevant.

[/ QUOTE ]

Define 'sufficiently safe'

[1800GAMBLER]

I checked the math, seems right.

0.6% chance of HIV shocks me, a lot. 1/167 americans have HIV?

0.002% chance of getting HIV with an infected partner shocks me too, i thought this would be way higher.

[mmbt0ne]

</font><blockquote><font class="small">En réponse à:</font><hr />

Jordan: He is in an 'Either/Or' situation. If Sarah doesnt have HIV, then he will never contract HIV over that year. IF she is, however, the probability of him contracting HIV =

1 - (499/500)^180 = 0.3026

Since, Jordan estimates the probability of Sarah having HIV is 0.3%, his final chance of contracting is:

= 0.0907%

[/ QUOTE ]

Ok, fine.

</font><blockquote><font class="small">En réponse à:</font><hr />
Jason: His equation looks like:

1 - P(Getting HIV)

= 1 -

(1 - (1.2/100*1/500))^20*(1-(4/100)*(1/500))^6

= 0.0959%

[/ QUOTE ]

BUZZ!!!!

Sorry, but now you're doing it differently. Now you have the percentage she is HIV+ included with the base of the exponential.

OK, I'M CHANGING THIS.

Correct form for Jason:

Bar Skanks
1-(499/500)^20 = 0.0392
0.0392*0.012 = 0.0004710

Whores
1-(499/500)^6 = 0.0119
0.0119*0.04 = 0.0004776

TOTAL
0.0004710+0.0004776 = 0.0949%


Don't be so mean to Jason, he's not that much more likely at all. Of course, Jordan's situation could be resolved very easily, and he would know automatically how safe it is to bang away.

[M2d]

[ QUOTE ]
He will never have sex with another female, nor is he an IV drug user.

[/ QUOTE ]
this doesn't preclude Sarah from having affairs and bringing home cooties. How do we know that she doesn't have a closet crack habit and is allowing bisexual man-whores from west hollywood bareback her for the rock?

[CallMeIshmael]

[ QUOTE ]
BUZZ!!!!

Sorry, but now you're doing it differently. Now you have the percentage she is HIV+ included with the base of the exponential.

OK, I'M CHANGING THIS.

Correct form for Jason:

Bar Skanks
1-(499/500)^20 = 0.0392
0.0392*0.012 = 0.0004710

Whores
1-(499/500)^6 = 0.0119
0.0119*0.04 = 0.0004776

TOTAL
0.0004710+0.0004776 = 0.0949%


[/ QUOTE ]

I dont think you can add these probabilities. Because, he only has to get HIV ONCE. Your method includes times he gets it, BOTH from a bar skand AND a prostitute.

BUT, FWIW, that means your method should over estimate the true number. And, mine is higher than yours /images/graemlins/mad.gif


(perhaps we will have to wait for Jason to get back from the testing centre (by which I mean Vegas) to check our math)

[gumpzilla]

[ QUOTE ]

Define 'sufficiently safe'

[/ QUOTE ]

Your partner gets tested. She doesn't have it. She doesn't take intravenous drugs, she's monogamous. In other words, 0.0001% or some such in terms of likelihood of having HIV. At this point, almost any rates of sexual contact you choose given the numbers for the other guy will lead to vastly different rates of infection.

There's a pretty substantial difference between "somewhat safer" than average and vastly safer than average, and I think the latter can be established.

[Sponger15SB]

[ QUOTE ]
[ QUOTE ]
He will never have sex with another female, nor is he an IV drug user.

[/ QUOTE ]
this doesn't preclude Sarah from having affairs and bringing home cooties. How do we know that she doesn't have a closet crack habit and is allowing bisexual man-whores from west hollywood bareback her for the rock?

[/ QUOTE ]

This has nothing to do with the OP at all

[CallMeIshmael]

[ QUOTE ]
0.6% chance of HIV shocks me, a lot. 1/167 americans have HIV?

[/ QUOTE ]

Keeping in mind that is only adult americans.

[ QUOTE ]
0.002% chance of getting HIV with an infected partner shocks me too, i thought this would be way higher.

[/ QUOTE ]

This is almost never mentioned in the media (probably for good reason), and is why this little math tidbit seems so counterintuitive.

[CallMeIshmael]

[ QUOTE ]
Your partner gets tested. She doesn't have it. She doesn't take intravenous drugs, she's monogamous. In other words, 0.0001% or some such in terms of likelihood of having HIV. At this point, almost any rates of sexual contact you choose given the numbers for the other guy will lead to vastly different rates of infection.

There's a pretty substantial difference between "somewhat safer" than average and vastly safer than average, and I think the latter can be established.

[/ QUOTE ]

Yeah. As soon as someone is tested, or is a virgin/non drug user, you're pretty much in for a safe ride.


The 0.3% estimate I gave for a 'clean' girl was just off the top of my head. I have no idea what a good estimate is.

[SmileyEH]

[ QUOTE ]


[ QUOTE ]
0.002% chance of getting HIV with an infected partner shocks me too, i thought this would be way higher.

[/ QUOTE ]

This is almost never mentioned in the media (probably for good reason), and is why this little math tidbit seems so counterintuitive.

[/ QUOTE ]

Yeah, it would really suck if that got out to the gen. public.

-SmileyEH

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
He will never have sex with another female, nor is he an IV drug user.

[/ QUOTE ]
this doesn't preclude Sarah from having affairs and bringing home cooties. How do we know that she doesn't have a closet crack habit and is allowing bisexual man-whores from west hollywood bareback her for the rock?

[/ QUOTE ]

This has nothing to do with the OP at all

[/ QUOTE ]


LOL... I knew someone was going to go there.


FWIW, this does have nothing to do with me. I picked the name Sarah, because I dont really know anyone with that name. (though the name Jason was picked to mock the nit)

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]


[ QUOTE ]
0.002% chance of getting HIV with an infected partner shocks me too, i thought this would be way higher.

[/ QUOTE ]

This is almost never mentioned in the media (probably for good reason), and is why this little math tidbit seems so counterintuitive.

[/ QUOTE ]

Yeah, it would really suck if that got out to the gen. public.

-SmileyEH

[/ QUOTE ]

"The Great Homecoming F[/i]uck Fantasy"

http://www.archiviokubrick.it/film/fmj/foto/papillon01.jpg

[blendedsuit]

theres no way this is correct. [ QUOTE ]

The probability of someone contracting HIV through unprotected sex with an HIV-postitve partner is 0.002 (This is the upper bound, taken from source)

[/ QUOTE ]
I looked at the study.

[mmbt0ne]

</font><blockquote><font class="small">En réponse à:</font><hr />
</font><blockquote><font class="small">En réponse à:</font><hr />
BUZZ!!!!

Sorry, but now you're doing it differently. Now you have the percentage she is HIV+ included with the base of the exponential.

OK, I'M CHANGING THIS.

Correct form for Jason:

Bar Skanks
1-(499/500)^20 = 0.0392
0.0392*0.012 = 0.0004710

Whores
1-(499/500)^6 = 0.0119
0.0119*0.04 = 0.0004776

TOTAL
0.0004710+0.0004776 = 0.0949%


[/ QUOTE ]

I dont think you can add these probabilities. Because, he only has to get HIV ONCE. Your method includes times he gets it, BOTH from a bar skand AND a prostitute.

BUT, FWIW, that means your method should over estimate the true number. And, mine is higher than yours /images/graemlins/mad.gif


(perhaps we will have to wait for Jason to get back from the testing centre (by which I mean Vegas) to check our math)

[/ QUOTE ]

Ok, we have event A he gets it from a skank, and event B he gets it from a whore.

P(AUB) = P(A) + P(B) - P(AnB)

In this case P(AnB) is 2.24E-07, which wouldn't even affect the number as I wrote it. Of course, this is necessary for all the combinations of A's and B's for that individual number too, but the chance of getting HIV is so low (as you can see) that subtracting the chances that he would've contracted it more than once is pretty much pointless.

If my numbers are wrong, it's by ~0.0002% tops.

[RacersEdge]

I believe your math is right.

Does the .002 = P(male contracting from female) or just an average going both ways - M to F and F to M? (Too lazy to read all those references.)

[CallMeIshmael]

[ QUOTE ]
theres no way this is correct. [ QUOTE ]

The probability of someone contracting HIV through unprotected sex with an HIV-postitve partner is 0.002 (This is the upper bound, taken from source)

[/ QUOTE ]
I looked at the study.

[/ QUOTE ]

Explain further...

[CallMeIshmael]

[ QUOTE ]
Does the .002 = P(male contracting from female) or just an average going both ways - M to F and F to M? (Too lazy to read all those references.)

[/ QUOTE ]

Average both ways. And, its easier for the man to give it (though, it seems you knew that).

Also... the thing with that study, is that only 92% didnt use codoms (but, they got a number that was smaller than the one I used), so its not 100% accurate or anything. And, another site I found had it at like 1 in 400. But the actual chance isnt really going to kill the results of the test. Either way, it'll be close.

[CallMeIshmael]

[ QUOTE ]
theres no way this is correct. [ QUOTE ]

The probability of someone contracting HIV through unprotected sex with an HIV-postitve partner is 0.002 (This is the upper bound, taken from source)

[/ QUOTE ]
I looked at the study.

[/ QUOTE ]


Here are four more links that give an estimate in the same ballpark.

Is your claim based on some scientific knowlege, or simply that it doesnt 'feel' right? At this point, it seems pretty unlikely that Im way off with that estimate.

1 (http://www.cdpc.com/s6.htm)
2 (http://www.findarticles.com/p/articles/mi_qa3634/is_200109/ai_n8983834?cm_ven=YPI)
3 (http://www.thebody.com/cdc/news_updates_archive/apr18_01/uganda.html)
4 (http://www.medicalnewstoday.com/index.php?newsid=19058)

[Mayhap]

If you keep it in your pants, you don't have to do any math.

[RacersEdge]

I'm not really shocked by this result - but maybe it's becasue I'm a Six Sigma guy, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[mason55]

[ QUOTE ]
I'm not really shocked by this result - but maybe it's becasue I'm a STATISTICS NERD, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[/ QUOTE ]

[SmileyEH]

[ QUOTE ]
I'm not really shocked by this result - but maybe it's becasue I'm a Six Sigma guy, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[/ QUOTE ]

What does that mean?

-SmileyEH

[RacersEdge]

[ QUOTE ]
[ QUOTE ]
I'm not really shocked by this result - but maybe it's becasue I'm a STATISTICS NERD, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[/ QUOTE ]

[/ QUOTE ]

lol, no I find Six Sigma gets me a lot more hits at monster /images/graemlins/tongue.gif

[mmbt0ne]

</font><blockquote><font class="small">En réponse à:</font><hr />
I'm not really shocked by this result - but maybe it's becasue I'm a Six Sigma guy, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[/ QUOTE ]

If we could never mention 6-sigma again, or anything pertaining to it, that'd be great. Motorola's a dick company for starting that concept.

Next thing you know we'll be setting up control charts in this thread. Maybe a 2^k full factorial ANOVA?

Also, I thought it was 3.6E-06?

EDIT: Nope it's 3.4 ppm. I don't know why I thought it was 1.8 per side.

[gumpzilla]

[ QUOTE ]

What does that mean?

[/ QUOTE ]

Lowercase sigma is the traditional symbol for standard deviation. In one sigma, the amplitude of the normal distribution falls off by a factor of 1/e. In the context the previous poster was using it in, to talk about something that falls outside of six sigmas means that you're talking about events in the very far tails of the normal distribution, at least six standard deviations away from the center. If you look up the error function online you can find numerical values for this kind of thing.

[M2d]

[ QUOTE ]

Quote:

Quote:
He will never have sex with another female, nor is he an IV drug user.


this doesn't preclude Sarah from having affairs and bringing home cooties. How do we know that she doesn't have a closet crack habit and is allowing bisexual man-whores from west hollywood bareback her for the rock?



This has nothing to do with the OP at all

[/ QUOTE ]

OP said

[ QUOTE ]

Jordan: He is in an 'Either/Or' situation. If Sarah doesnt have HIV, then he will never contract HIV over that year. IF she is, however, the probability of him contracting HIV =

[/ QUOTE ]
so it does have something to do with the op. it's not an either/or situation, since she can start the year hiv(-) and become hiv(+) sometime before the year is over.

[RacersEdge]

[ QUOTE ]
[ QUOTE ]
I'm not really shocked by this result - but maybe it's becasue I'm a Six Sigma guy, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[/ QUOTE ]

What does that mean?

-SmileyEH

[/ QUOTE ]

It's a quality thing. If you have process that when it varies 6 standard deviations above and belows it's mean it still produces good parts (think manufacturing) then your process has 6 sigma quality....i.e you always want to reduce the variabilty in your processes..

[CallMeIshmael]

I took sponger's comments to be more along the lines of "he is currently dating someone named Sarah"

But, I also see what you mean as a possibilty.

Sponger, which was it?

[DrunkIrish05]

[ QUOTE ]
[ QUOTE ]
I'm not really shocked by this result - but maybe it's becasue I'm a Six Sigma guy, and even though .002 seems low, it's really only about 3 sigma rate. (6 sigma = .0000034 "defect" rate).

[/ QUOTE ]

If we could never mention 6-sigma again, or anything pertaining to it, that'd be great. Motorola's a dick company for starting that concept.

Next thing you know we'll be setting up control charts in this thread. Maybe a 2^k full factorial ANOVA?

Also, I thought it was 3.6E-06?

EDIT: Nope it's 3.4 ppm. I don't know why I thought it was 1.8 per side.

[/ QUOTE ]

Over my head, someone care to explain?

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
BUZZ!!!!

Sorry, but now you're doing it differently. Now you have the percentage she is HIV+ included with the base of the exponential.

OK, I'M CHANGING THIS.

Correct form for Jason:

Bar Skanks
1-(499/500)^20 = 0.0392
0.0392*0.012 = 0.0004710

Whores
1-(499/500)^6 = 0.0119
0.0119*0.04 = 0.0004776

TOTAL
0.0004710+0.0004776 = 0.0949%


[/ QUOTE ]

I dont think you can add these probabilities. Because, he only has to get HIV ONCE. Your method includes times he gets it, BOTH from a bar skand AND a prostitute.

BUT, FWIW, that means your method should over estimate the true number. And, mine is higher than yours /images/graemlins/mad.gif


(perhaps we will have to wait for Jason to get back from the testing centre (by which I mean Vegas) to check our math)

[/ QUOTE ]

Ok, we have event A he gets it from a skank, and event B he gets it from a whore.

P(AUB) = P(A) + P(B) - P(AnB)

In this case P(AnB) is 2.24E-07, which wouldn't even affect the number as I wrote it. Of course, this is necessary for all the combinations of A's and B's for that individual number too, but the chance of getting HIV is so low (as you can see) that subtracting the chances that he would've contracted it more than once is pretty much pointless.

If my numbers are wrong, it's by ~0.0002% tops.

[/ QUOTE ]

Im beginning to think you're wrong on this one, and I was wrong on the first one (the 180 one), in that the weighted average assumes that there is an X% chance that we will contract HIV from villian, whereas in actually, the chance is 0 once its already been contracted, and thus we're over shooting.

Im too tired to do the math now, but Ill post again tomorrow.

[M2d]

[ QUOTE ]
I took sponger's comments to be more along the lines of "he is currently dating someone named Sarah"

But, I also see what you mean as a possibilty.

Sponger, which was it?

[/ QUOTE ]
I didn't know that, so anything I wrote that may have been personal was inadvertant.

[CallMeIshmael]

[ QUOTE ]
I didn't know that, so anything I wrote that may have been ersonal was inadvertant.

[/ QUOTE ]

WAY too much confusion in this thread!! /images/graemlins/blush.gif

Im NOT dating someone named Sarah, I was saying I thought sponger was implying that.

[RacersEdge]

[ QUOTE ]
Next thing you know we'll be setting up control charts

[/ QUOTE ]

I'm already thinking of control charts for my poker win rate. /images/graemlins/cool.gif

[Skipbidder]

[ QUOTE ]
0.002% chance of getting HIV with an infected partner shocks me too, i thought this would be way higher.

[/ QUOTE ]

It should shock you. It is way out of line with published estimates. 0.2% would be much closer.
Are we sure that there wasn't an error here?
The number might have been presented as 0.002 in a paper and someone stuck a percentage sign on the back of it by accident. 0.002 would be 0.2%
It would have to be 0.00002 to be 0.002%

[Sponger15SB]

[ QUOTE ]
I took sponger's comments to be more along the lines of "he is currently dating someone named Sarah"

But, I also see what you mean as a possibilty.

Sponger, which was it?

[/ QUOTE ]

lol, this post really confused the [censored] out of me because my girlfriends name is sarah, and I was wondering how you knew that.

anyways, I reread the OP...

[ QUOTE ]
Jordan: Jordan is a successful good looking guy, and has managed to find himself a great wife: Sarah. They've talked about their past sexual history. Sarah is not a virgin, but she isnt a whore either. But, she has never been tested. Jordan would consider her less likely to have HIV than a member of the US adult population picked at random (that number is 0.6% ( source)). He is willing to cut that number in half, to 0.3%. Sarah is on the pill, and when she and Jordan have sex, he doesnt wear a condom. He estimates they will have sex 15 times per month over the course of the next year. (180 times in total) He will never have sex with another female, nor is he an IV drug user.


[/ QUOTE ]

And I guess this was the part that confused me, and it didn't say that both were going to be 100% faithful, just the guy.


Also, I find this paradox to suck because Jordan should just get his wife tested, and if she is not HIV+ and they aren't monogomous there is a 0% chance of contracting aids, while there will always be a chance with Jason.

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
0.002% chance of getting HIV with an infected partner shocks me too, i thought this would be way higher.

[/ QUOTE ]

It should shock you. It is way out of line with published estimates. 0.2% would be much closer.
Are we sure that there wasn't an error here?
The number might have been presented as 0.002 in a paper and someone stuck a percentage sign on the back of it by accident. 0.002 would be 0.2%
It would have to be 0.00002 to be 0.002%

[/ QUOTE ]

Reread the OP. I said the probability was 0.002, NOT 0.002%.

[CallMeIshmael]

My bad. Yes, Sarah is also 100% monogamous.


Also... yes, getting her to take a test is clearly +EV. The point was more that safeness is not the only factor, as volume can change things.

[Sponger15SB]

[ QUOTE ]
My bad. Yes, Sarah is also 100% monogamous.

[/ QUOTE ]

You don't know that. My sarah would never cheat on me /images/graemlins/mad.gif Take it back!

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
My bad. Yes, Sarah is also 100% monogamous.

[/ QUOTE ]

You don't know that. My sarah would never cheat on me /images/graemlins/mad.gif Take it back!

[/ QUOTE ]


You have no idea how much I tapped that last night.

[mmbt0ne]

Ok, how about this. c = Choose, as in 180c1 = 180 choose 1.

Jordan:

P(contracting) = 0.003x0.002 = 0.000006

P(HIV+) = (180c1)[(0.000006)^1][(1-0.000006)^179]
P(HIV+) = 0.00108 or 0.108%


Jason:

P(contraction_skank) = 0.012x0.002 = 0.000024

P(HIV+_1skank) = (20c1)[(0.000024)^1][(1-0.000024)^19]
P(HIV+_1skank) = 0.0004798

P(contraction_whore) = 0.04x0.002 = 0.00008

P(HIV+_1whore) = (6c1)[(0.00008)^1][(1-0.00008)^5]
P(HIV+_1whore) = 0.0004798

P(HIV+) = 0.0004798 + 0.0004798 - (0.004798)^2
P(HIV+) = 0.0009594 or 0.09594%

[Skipbidder]

[ QUOTE ]
Reread the OP. I said the probability was 0.002, NOT 0.002%.

[/ QUOTE ]

Yes, but later in the thread you responded to the guy who was surprised that the transmission rate was only 0.002%. You quoted his figure but didn't correct it.

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
Reread the OP. I said the probability was 0.002, NOT 0.002%.

[/ QUOTE ]

Yes, but later in the thread you responded to the guy who was surprised that the transmission rate was only 0.002%. You quoted his figure but didn't correct it.

[/ QUOTE ]

I think its pretty safe to assume that I simply didnt see the % sign.

[OtisTheMarsupial]

News flash: HIV is more concentrated and more easily transmitting through blood.

This is why women and gay men are much more likely to get HIV than straight men - because the person being penetrated is more likely to get a little tear that the virus gets into. It's not as likely that the penetrator will get that little tear, particularly if he's circumized.

Duh, this is why AIDS in America is a gay disease whereas in the rest of the world it's not.

Also, if Sarah gets tested twice in a year, she's cool. But Jason will almost definitely get some sort of bug, most likely HPV, which can lead to cancer and is NOT cool.

[jason_t]

I fu[/i]cked a stripper while you take it in the a[/i]ss. My chances of contracting HIV from a carrier are lower than yours.

http://liverevolt.com/seldomsober/fishf.gif

[OtisTheMarsupial]

[ QUOTE ]
Also, I find this paradox to suck because Jordan should just get his wife tested, and if she is not HIV+ and they aren't monogomous there is a 0% chance of contracting aids, while there will always be a chance with Jason.

[/ QUOTE ]

Yes, this is exactly the thing. Jordan's chances of contracting HIV will go down while Jason's remain the same.

Course, he could also work in something about how almost 50% of married persons cheat...

[Skipbidder]

I understand now that you were using 0.2%. I just wanted to make sure before I spent any time on it tomorrow. (I don't have good database and journal access at home.) If people were actually arguing 0.002%, then I would provide journal citations to the contrary.

This is still 1 in 500. You've taken worse beats than that at the poker table, and AIDS is a very bad beat.

[Skipbidder]

I don't know that any of your math is wrong, but I believe that some of your assumptions are quite different from those that I would have made.

I'm pretty sure that I had more sex in the eight years prior to being married than I did during my eight year marriage. You've got Jordan having sex 6 times as frequently as Jason. I'm not sure how accurately this would translate to most folks.

Another thing to consider is the question of whether or not a one-night stand is likely to consist solely of one episode of insertive vaginal intercourse. Very few of mine ever did (if I recall correctly...I'm getting old). Oral sex has a non-zero transmission rate (literature about this rate is subject to a lot more disagreement than anal or vaginal sex).

The percentage chance that you've given Sarah of being positive seems very, very high to me. If she has not engaged in intravenous drug use or prostitution, then her percentage is probably quite a bit lower than you suggest.
Public health officials in my state (Illinois) opposed mandatory AIDS testing to get marriage certificates on the basis that the prevalance was so low that even fairly good tests would generate many more false positives than true positives (and waste a lot of money). This was written up in JAMA. The seroprevalance among applicants for marriage licenses was 0.011% (8 out of 70,846). This is now becoming an outdated study, but it still seems to me that your hypothetical Sarah would be closer to 0.011% than 0.3% unless there is something that you are not telling us about Sarah. (She turned tricks to buy smack and spent some time in prison because of it.)

[fimbulwinter]

this is not mentioned because HIV is an overwhelmingly homosexual/IV drug user disease. government needs the fiscal support of middle america to fund hiv research, hecnce the heterosexual AIDS myth was born.

fim

[CallMeIshmael]

[ QUOTE ]
This is why women and gay men are much more likely to get HIV than straight men - because the person being penetrated is more likely to get a little tear that the virus gets into. It's not as likely that the penetrator will get that little tear, particularly if he's circumized.


[/ QUOTE ]

I believe you're going to have to pull some numbers to prove that women getting aids from men is "much more likely" to happen than men getting it from women. Because, Im pretty sure you're just making that up.

Though, the general consenus, is that male to female transmission is probably more likely, the study I quoted found:

[ QUOTE ]
Studies of discordant couples in Europe and the USA generally report higher male-to-female transmission efficiency than female-to-male, although these investigations had few female HIV-1-positive index partners.2-5 By contrast, we found a higher transmission probability per act from women to men than from men to women, which, although not significant, was consistent with previous incidence data from Rakai among HIV-1-discordant couples 15,22 and in the general population.14 Similarly, higher female-to-male transmission has been reported from other less-developed countries23 Several African studies show that HIV-1 prevalence and incidence are higher in young women than in young men,12 but these data suggest that the sex-specific differentials in HIV-1 prevalence are unlikely to be caused by sex differences in the efficiency of HIV-1 transmission.

[/ QUOTE ]

[ QUOTE ]
Duh, this is why AIDS in America is a gay disease whereas in the rest of the world it's not.

[/ QUOTE ]

A) This doesnt make any sense at all
B) You will have to back that up as well

[CallMeIshmael]

FWIW, I never intended the OP to accurately model any real life occurance.

It was more a look at how the frequency of the act can have major influences on the probability of contraction.

[jakethebake]

[ QUOTE ]
Course, he could also work in something about how almost 50% of married persons cheat...

[/ QUOTE ]

Are you serious? Where does that stat come from?

[RacersEdge]

[ QUOTE ]
It was more a look at how the frequency of the act can have major influences on the probability of contraction.



[/ QUOTE ]

Yeah, it's just like transactions at a credit card company or a bank. If they were say, only 99.5% accurate, the entire financial system would be a mess becasue there are millions of transaction per day.

[CallMeIshmael]

[ QUOTE ]
Ok, how about this. c = Choose, as in 180c1 = 180 choose 1.

Jordan:

P(contracting) = 0.003x0.002 = 0.000006

P(HIV+) = (180c1)[(0.000006)^1][(1-0.000006)^179]
P(HIV+) = 0.00108 or 0.108%


Jason:

P(contraction_skank) = 0.012x0.002 = 0.000024

P(HIV+_1skank) = (20c1)[(0.000024)^1][(1-0.000024)^19]
P(HIV+_1skank) = 0.0004798

P(contraction_whore) = 0.04x0.002 = 0.00008

P(HIV+_1whore) = (6c1)[(0.00008)^1][(1-0.00008)^5]
P(HIV+_1whore) = 0.0004798

P(HIV+) = 0.0004798 + 0.0004798 - (0.004798)^2
P(HIV+) = 0.0009594 or 0.09594%

[/ QUOTE ]

I think this is right, and its how Im doing it now.


I'll PM BruceZ to double check.

[sam h]

[ QUOTE ]
Sarah is not a virgin, but she isnt a whore either. But, she has never been tested. Jordan would consider her less likely to have HIV than a member of the US adult population picked at random (that number is 0.6% ( source)). He is willing to cut that number in half, to 0.3%.

[/ QUOTE ]

I think this is where yours assumptions may be faulty. People like Sarah who have generally practiced safe-sex and have not been, or only rarely been, with "at-risk" populations have a much lower chance of having HIV.

[CallMeIshmael]

[ QUOTE ]
I think this is where yours assumptions may be faulty. People like Sarah who have generally practiced safe-sex and have not been, or only rarely been, with "at-risk" populations have a much lower chance of having HIV.

[/ QUOTE ]


The 0.3% was the assumption that I had no idea how to gauge.


BUT, fwiw, if you have two people:

1. 180 sex acts with 1 low risk person
2. 20 sex acts, each with 20 different low risk persons

The former is WAY more likely to get HIV.

[mantasm]

Bad news everyone. Turns out .2% of the people who clicked on this thread now has super AIDS. I'm clean though.