Some HIV Insight.

[Fellow Traveler]

I recently came across a blog post that provides some interesting insight on the whole 'HIV/circumcision' issue and I'd thought I'd share the analysis I just recently read. I share this in part to provide some insight on just how stupid that Australian article was though I know you all know that, it might help you when talking to others. It surrounds the real probability of contracting HIV over a given number of sexual encounters. To determine the probability of not becoming infected you can use the following formula:

(1 - [chance of transmission from sex])^[sexual encounters]

Now for the estimates, let's assume that there is a risk reduction of 50% for circumcised men and a 90% reduction for condom use. I actually think condom use is closer to 100% but just accept it for now. The probability of infection in any one encounter with an HIV positive partner varies but we'll estimate that the chance of infection is 0.05%. That means a male having unprotected sex with an HIV positive women. The number of sexual encounters is important too. If we assume 100, then the probability of not being infected after 100 encounters with an HIV positive woman would be:

(1-0.0005*1)**100 ~= 95.1 (intact)
(1-0.0005*0.5)**100 ~= 97.5 (circumcised assuming about 50% protection)
(1-0.0005*0.1)**100 ~= 99.5 (with a condom assuming 90% protection)

This assumes that circumcision does provide such protection and that your son would have 100 encounters with an HIV positive partner after which the difference in the possibility of infection is 2.4%.

The truth is I don't think the scenario is relevant in the West where (for the most part) we tend to maintain long term stable relationships. This also doesn't take into account that the prevalence of HIV is very low to begin with. So let's do that.

In the US, the prevalence in the general population is estimated at 5 in 1000 (possibly less but we'll go with that). So, if I have 1000 random encounters I might expect 5 to be HIV positive and then the numbers might look like this:

(1-0.0005*1)**5 ~= 99.7
(1-0.0005*0.5)**5 ~= 99.8
(1-0.0005*0.1)**5 ~= 99.9

So a rough estimate is that if ones one were to have 1,000 random heterosexual encounters with 1,000 different partners of unknown HIV status the possibility that they would come out of it HIV positive is .3% (intact) .2% (circumcised) and .1% (condom) a difference of 1 in 1,000. Since prevalence doesn't run the same in all 'walks' of life I am guessing it would be much lower for the vast majority of Americans plus most people don't have that kind of sexual history. All of those who've had 1,000 randoms sexual partners please raise your hand.

I just thought the numbers were interesting to show people how much impact there really is, even if we were to accept the purported benefit. I also just thought of something that might bring this more in line with reality. This is just a way to demonstrate the futility of circumcision and show how that purported 50% (if you were to take it at face value) adds up over time.

I wanted to post this because of that ridiculous Australian article. Given that in Australia the prevalence is estimated at 1 in 1000, the numbers look like this:

(1-0.0005*1)**1 ~= 99.95
(1-0.0005*0.5)**1 ~= 99.975
(1-0.0005*0.1)**1 ~= 99.995

2.5 one-hundredths of a percent.

Enjoy.

[kriket]

Well, I'm not quiiiite at 1,000.


Does anyone know biologically why people seem to think that circs reduce the risk? I've looked everywhere and all I can find is the one study, and it never tells me what about a circ prevents AIDS.

[Claire and Boys]

Nice number crunching!! Makes it look a lot different compared to the "60% less chance" they are reporting..many of them don't even state that it is per encounter not overall.

kriket, as I understand it, it's got something to do with the langerhans cells in the foreskin, they are claiming they act like hiv "receptors" but this has been contested. Plus langerhans cells are also in females genitals too, strangely though they're not advocating chopping bits off them to reduce hiv.... I wonder why?

[SleeplessMommy]

Originally Posted by Claire and Boys

... it's got something to do with the langerhans cells in the foreskin, they are claiming they act like hiv "receptors" but this has been contested. ...

The alleged "Achilles heal" of the male anatomy.

All sour grapes really - "I don't have one so it must not be any good" - the "researchers" in question would have been circed shortly after birth.

When we talk about interventions to prevent HIV infection, we need to talk about ALL of the intervention options -
* use of condoms with new partners
* use of condoms for non-vaginal intercourse due to higher chance of infection
* educating young women frankly about how HIV is transmitted, and the extremely increased risk of intercourse with IV drug users - who are much more likely to be infected.

[eepster]

Originally Posted by kriket

Well, I'm not quiiiite at 1,000.


Does anyone know biologically why people seem to think that circs reduce the risk? I've looked everywhere and all I can find is the one study, and it never tells me what about a circ prevents AIDS.

I know that the "scientist" who ran the study have there little theory as to why it worked, but I have my own theory as to why they saw an approx 50% reduction in transmission.

Since the studies only lasted 18 months, they really only prove that transmissoin is reduce for 18 mo following circ. When you consider that it take about 6 months after exposure to test positive, almost all of the positve HIV test cases will be from having been exposed during the first 12 months following the start of the study.

I believe that men are less likely to desire sexual intercourse for the first 3 or 4 months following painful surgery on their penises.

Less sex equals less exposure. While this is a real effect, it is a temporary one. If you get a baby circ'd at birth then he is protected for the 18 months of his life when he is least likely to be having sex.

[hanabi]

Circumcision & HIV

Hello all:

I am with Colorado NOCIRC and a fellow member forwarded me this post. I have been following the latest info on the HIV & Circumcision hype coming out of Africa and would like to share a bit of what I have learned. Forst a bit about myself, I am a practicing physicist and have never circumcised or caused the circumcision of anyone and as a man I simply would have preferred to have been asked. Somehow that doesn't seem to be too much consideration to ask for.

There were 3 African studies performed by pro-circumcision doctors (US doctors of course) regarding the effectiveness of adult circumcision in the prevention of HIV infection. These were carefully controlled studies and dispite the bias of the researchers I suspect the data are mostly valid. How they translate into effectiveness in the real world where men are not seen every 3 to 6 months by doctors, given free condoms and told they MUST wear condoms for every sex act is not known.

The epidemic in Africa is very much different from that in ALL developed countries, including the US and Australia. In Africa men frequent prostitutes and often have multiple sex partners. Women, especially sex workers, have no power to refuse sex if a man refuses to wear a condom. It has been estimated that 50% to 75% of sex workers in Africa between the age of 15 and 24 are infected. Thus it is nearly certain that men will encounter an infected woman if they engage in "risky behavior". This is not the main vector of infection in the US or Australia. The question of why is somewhat more speculative and some studies have shown that Langerhans cells have CD4 receptors on them which allow infection. All skin has Langerhans cells but the keritanised outer skin may provide a barrier. Of course a study also showed that Langerhans cells are part of the immune system secreting Langerin which helps to prevent bactirial and viral infection, including AIDS. However, once a high enough viral load has been delivered it overwhelms any protective effect with infection following. I must state that there is VERY little research supporting this and it is mostly speculative. I speculate that if you cut half the skin of of a man's penis, his chance of infection goes down. The studies show by 44% to 50% - funny that number coincides with the estimated amount of skin removed.

In the US, the major vector is from gay sex and countless large scale studies have shown circumcision has no effect in this case. The other major vector is intravenous drug use, which for obvious reasons surgery will not affect infection rates. So the effect in the US is for the minority vector of women to men. UNAIDS estimates the US HIV infection rate is 0.6%, 75% of whom are men, 16% of those from self reported heterosexual contact. Multiplying 0.006 X 0.75 X 0.16 = 0.0007 or 7 men in 10,000. If the effect seen in Africa translates to routine infant circ (which is pure 100% speculation that it does since no cause has been clearly identified) 10,000 circumcisions would save at most 3 men if all seven of the infected ones were intact 0.0007 X 0.44 = 0.0003. The other would not have benefited and needless to say some of the infected men were already cut so they got no benefit. The health ministry in Australia ran the same numbers for thier demographics and found NO REASON TO IMPLEMENT RIC programs. There is no cost savings, period.

I recently read an article from Australia about there being a curious backlash from older cut men who were now looked upon as amputees by thier young intact brothers and sisters. They are now running around saying, but wait, there is nothing wrong with us, we are OK, we promise. The most ardent of these is a professor named Brian Morris. He is NOT an MD. He believes that an uncut boy will spontaneously combust or otherwise die horribly and since he lost the battle in his own country, he has staked out territory in the US, the last circumcising country in the developed world.

Now for some other news. In a recent study funded by the Gates Foundation the interim report showed a dramatic increase in HIV infections of women married to cut adult men. These men were cut as adults to see if there was a positive effect on thier wives and the results were "dissapointing" according to Dr. Wawer the study leader. The sample was too small for the data to reach statistical signifigance, but if true would represent an increase of 4 HIV infected women in the US to save 3 men. So much for equality between the sexes if true. Of course these are preliminary results and were played down with words like it might take more than 6 months for an HIV infected man to recover from the surgery while only 6 weeks were required in the other studies. My speculation is that anything from a mostly healed surgical scar would be small compared to 4 to 6 ml of semen and if a condom was used then we REALLY have no idea what is going on here.

The final analysis is the US has the highest rate of HIV infection in the developed world. Scandanavian countries, where circ is unknown, have a tenth the rate we do. Even France with it's reputation for love has less. You have to include Brazil and India, developing countries, to reach the US level. Laumann determined in 1996 that men circed at birth in the US exhibited a wider range of sexual behavior and practices than intact men. The data are clear and if those behaviors are risky, then that might explain the US high rate of infection. Sadly, no one has investigated this further or even looked at why the European incidense of HIV is so low compared to the US, even though they circumcise no one in Europe.

Condoms have been determined to be 95% effective in preventing HIV infections and pregnancy. One study done in Itally showed 100% effectiveness in serodiscordant couples over a 3 year period and an estimated 15,000 intimate encounters. Studies done by Trojan and Durex have shown the effectiveness to be 99%. What they found was there are two types of condom failure, about 4% application errors and less than 1% product defects. They are currently carrying on research to study how to make condoms better to reduce the 1% number but couples must use condoms correctly in order for them to be effective and that requires education not surgery.

Finally, babies are not at risk for HIV from heterosexual contact. It would be massively cheaper and more effective to circumcise adult men who engage in risky behavior and let the ones who are responsible enjoy thier bodies as God made them. That, BTW is the only intervention that has shown to be effective in Africa - Adult circumcision of men who engage in risky behavior after behavior has been established. No one knows how this translates to infant circ and if they say they do, they are lying.

[gothnurse3]

The largest growing number of HIV infected people are women because their partners are unfaithful. It could be "the low down" ( a "straight" man having man on man sex...nobody knows or suspects this behavior) while in jail or experimenting with other men. I was surprised to learn that truck drivers have also been identified as a group that has increased significantly. It is said that every 10 minutes another American is infected with HIV.

All I can say( as an HIV healthcare worker) is... it is scary. I pray that we get some resolve to this.

[Fellow Traveler]

Originally Posted by hanabi

Hello all:
I am with Colorado NOCIRC and a fellow member forwarded me this post. I have been following the latest info on the HIV & Circumcision hype coming out of Africa and would like to share a bit of what I have learned. Forst a bit about myself, I am a practicing physicist and have never circumcised or caused the circumcision of anyone and as a man I simply would have preferred to have been asked. Somehow that doesn't seem to be too much consideration to ask for.

Welcome to the board Hanabi. Are you a physician or a physicist? I don't think I've encountered 'practicing' next to physicist so I thought it might be a typo (also because you said you've never circumcised). I am also courious if the numbers that were presented make sense to you.

Originally Posted by hanabi

There were 3 African studies performed by pro-circumcision doctors (US doctors of course) regarding the effectiveness of adult circumcision in the prevention of HIV infection. These were carefully controlled studies and dispite the bias of the researchers I suspect the data are mostly valid. How they translate into effectiveness in the real world where men are not seen every 3 to 6 months by doctors, given free condoms and told they MUST wear condoms for every sex act is not known.

Real world impact is the point and to that I suspect that what happens in Africa will be a long term dud.

Originally Posted by hanabi

In the US, the major vector is from gay sex and countless large scale studies have shown circumcision has no effect in this case. The other major vector is intravenous drug use, which for obvious reasons surgery will not affect infection rates. So the effect in the US is for the minority vector of women to men. UNAIDS estimates the US HIV infection rate is 0.6%, 75% of whom are men, 16% of those from self reported heterosexual contact. Multiplying 0.006 X 0.75 X 0.16 = 0.0007 or 7 men in 10,000. If the effect seen in Africa translates to routine infant circ (which is pure 100% speculation that it does since no cause has been clearly identified) 10,000 circumcisions would save at most 3 men if all seven of the infected ones were intact 0.0007 X 0.44 = 0.0003. The other would not have benefited and needless to say some of the infected men were already cut so they got no benefit. The health ministry in Australia ran the same numbers for thier demographics and found NO REASON TO IMPLEMENT RIC programs. There is no cost savings, period.

I recently read an article from Australia about there being a curious backlash from older cut men who were now looked upon as amputees by thier young intact brothers and sisters. They are now running around saying, but wait, there is nothing wrong with us, we are OK, we promise. The most ardent of these is a professor named Brian Morris. He is NOT an MD. He believes that an uncut boy will spontaneously combust or otherwise die horribly and since he lost the battle in his own country, he has staked out territory in the US, the last circumcising country in the developed world.

I remember reading about the work of the Australians. Do you have a link to the article you mentioned about this 'backlash'?

Originally Posted by hanabi

Now for some other news. In a recent study funded by the Gates Foundation the interim report showed a dramatic increase in HIV infections of women married to cut adult men. These men were cut as adults to see if there was a positive effect on thier wives and the results were "dissapointing" according to Dr. Wawer the study leader. The sample was too small for the data to reach statistical signifigance, but if true would represent an increase of 4 HIV infected women in the US to save 3 men. So much for equality between the sexes if true. Of course these are preliminary results and were played down with words like it might take more than 6 months for an HIV infected man to recover from the surgery while only 6 weeks were required in the other studies. My speculation is that anything from a mostly healed surgical scar would be small compared to 4 to 6 ml of semen and if a condom was used then we REALLY have no idea what is going on here.

I heard of that study too. I thought that they massaged the most recent data to make it 'balance out'.

Originally Posted by hanabi

The final analysis is the US has the highest rate of HIV infection in the developed world. Scandanavian countries, where circ is unknown, have a tenth the rate we do. Even France with it's reputation for love has less. You have to include Brazil and India, developing countries, to reach the US level. Laumann determined in 1996 that men circed at birth in the US exhibited a wider range of sexual behavior and practices than intact men. The data are clear and if those behaviors are risky, then that might explain the US high rate of infection. Sadly, no one has investigated this further or even looked at why the European incidense of HIV is so low compared to the US, even though they circumcise no one in Europe.

I'd speculate that they healthier first world Europeans might have stronger immunity via more Langerin production. As you pointed out in De Witte, cells only became compromised when very high viral levels were introduced. We know viral loads are highest in the first few months after infection. So with African concurrent sexual relationships and weaker langerin barrier due to poverty and malnutrition this could lead to higher rates in Africa and lower rates in Europe. In healthy populations the foreskin may protect quite well and possibly reduce the rate of transmission to women.

Why would they look at that anyway? It might rock the boat.

Originally Posted by hanabi

Condoms have been determined to be 95% effective in preventing HIV infections and pregnancy. One study done in Itally showed 100% effectiveness in serodiscordant couples over a 3 year period and an estimated 15,000 intimate encounters. Studies done by Trojan and Durex have shown the effectiveness to be 99%. What they found was there are two types of condom failure, about 4% application errors and less than 1% product defects. They are currently carrying on research to study how to make condoms better to reduce the 1% number but couples must use condoms correctly in order for them to be effective and that requires education not surgery.

That was the 1994 study right?

[Fellow Traveler]

Originally Posted by gothnurse3

The largest growing number of HIV infected people are women because their partners are unfaithful. It could be "the low down" ( a "straight" man having man on man sex...nobody knows or suspects this behavior) while in jail or experimenting with other men. I was surprised to learn that truck drivers have also been identified as a group that has increased significantly. It is said that every 10 minutes another American is infected with HIV.

All I can say( as an HIV healthcare worker) is... it is scary. I pray that we get some resolve to this.

I've heard that inmates are a big problem. I wonder, do we test and segregate inmates based on HIV status? If not why? That would seem like a no brainer.

I think we all want a resolution to the problem but I hope you'd agree infant circumcision isn't it.

[Fellow Traveler]

[reviewing]

[hanabi]

HIC and Circ

Well this is irriating. I just wrote a reply and it got deleted because the web site thought I was logged out when I was clearly logged in. GRRRRR.

Second reply to jwhispers:

Welcome to the board Hanabi. Are you a physician or a physicist? I don't think I've encountered 'practicing' next to physicist so I thought it might be a typo (also because you said you've never circumcised). I am also courious if the numbers that were presented make sense to you.

I am a physicist not a physician. I say practicing because a) I am not retired and b) I still do physics even tho I work for industry. I am an applied rather than theoretical kinda guy. I only mentioned this to help establish a credential in a group who I had never spoken with before.

The calculation looks to me to be correct. I did not check the numbers just the formula. The issue is the assumptions. Here you assume the single event risk is 0.05% which may or may not be a valid number. So far as I know there is no good estimate on the single exposure risk of contracting HIV. The Afican studies IIRC showed ~2.1% for intact men and 0.85% for cut men. These numbers seem high to me since the risk is about 6% to 7% for couples who never use condoms. Percent in this context is the sme as birth control or 6 to 7 out of 100 people in a sexually active relationship over a one year period. 2.1 is very high for consistent condom use since condoms should be 80% to 95% effective so the real numbers should be 1.4% to 0.35%. This is an unexplained weakness in the studies. There has also been criticism because the intervention group was abstinant for 6 weeks or 11% of the one year study period (they were neded early).

Real world impact is the point and to that I suspect that what happens in Africa will be a long term dud.

Certainly our experience in the US would lead one to expect you are right since the US HIV rate is greater than non-circumcising northern Europe's by a factor of 10. To put that into perspective, the US has MORE heterosexual HIV positive men and women than Sweden has HIV positive people period (ie sexual preference not accounted for). Genital cutting has not worked at all in the US.

I remember reading about the work of the Australians. Do you have a link to the article you mentioned about this 'backlash'?

No but it was a news piece not a scientific or technical paper. CIRP has several such articles on file.

I

heard of that study too. I thought that they massaged the most recent data to make it 'balance out'.

I doubt they "massaged the data" more likely they simply ignored it by making some wild conjecture without benefit of data. This is what they do with the Sorrels study too (available at: http://www.doctorsopposingcircumcisi...rells_2007.pdf) by only quoting the data about the glans and ignoring the fact that that the tip of the foreskin is 12X more sensitive than the glans and ~5X more sensitive than anything left on a cut man. I find this to be beyond contempt, if you quote an article you quote the article and its major conclusions, but this is politics not science. Any man can qualitatively prove for himself the Sorrels data are true, even circumcised men. Read the paper and locate on your "prima-digit" the places specified. Now simply take a fingernail and very very lightly drag it across those areas noticing which is more sensitive than which. Practice on the underside of your forearm, your palm and your lip (sorry ladies but this is as far as you can experience, tho you could try it out on your main squeeze) forearm = topside shaft skin; palm = bottom side shaft skin; lip = circ scar on glans side. 100% of men who have tried this have proven Sorrels 100% correct. Sadly, the most sensitive areas have been amputated on most US men. Quite a pity that!

Yes the condom effectiveness study was 1994 A Longitudinal Study of Human Immunodeficiency Virus Transmission by Heterosexual Partners

Isabelle De Vincenzi

Reply to gothnurse3
I have not read anywhere that anyone has come up with a satisfactory explaination of the increasing rate in women. there have been several studies trying to get to the root of this problem but none that I am aware of blame infidelity as the chief cause. They typically blame 3 things: 1) increase in drug use among men who then give it to thier women; 2) increased number of partners acquireing HIV from a previous partner and giving it to thier current one [as opposed to multiple concurrent partners] 3) increase in the number of sexually active patners women are with. With 1% of the population in prison in the US (more people behind bars than with HIV) there could be an effect there but I bet it is small]. Truckdrivers? who knows, when I used to listen to the CB radio many moons ago I think there were lots of "unofficial brothels" in many remote locations so that could be true, but I have no idea today. And all the straight men I know, which is a lot, are pretty repulsed by gay sex as an activity they would like to "experiment with", that or they deserve Oscars.

for what it is worth
Hanabi