Statistics on Herpes-2 Confusing

[Dobot]

I've been reading a lot of stats on the probability of contracting Herpes-2. Here is what I gathered:

1) 25% of the population is infected with Herpes 2
2) 3-5% per year of contracting HSV-2 without the use of condoms
3) 40% Rate of protection against acquiring hsv2 with condom use
4) 50% risk reduction with use of Valtrex alone (unprotected sex)...modest estimate

So putting this together, I assume if you use a condom the risk is cut down to a almost 1-2% chance of catching HSV-2 while using a condom?

--So how can 1 in 4 people be infected with HSV-2 with odds like this? I just don't get it. 1-2% chance seems so low.

It seems like the odds should be more like 3.5 people out of 100 have herpes...not 25 out of 100....Even without the use of condoms, the statistic, at worst, should be 5 people out of 100 have HSV-2? According to the stat above saying "3-5% per year of contracting HSV-2 without the use of condoms."

Is this the effect of an annual compounding? Odds increase as years do?

Please explain what I'm missing here. I would love a doctor's explanation on this one, or do they only answer questions for $$$$. That would be sad :(

Thanks for any help.

[Dobot]

Thank you guys,

this is all really helpful. It's a very nice thing you all are doing to help educate people.

[gracefromHHP]

There is info on the valtrex and transmission study on their website or you can register for free at the NEJM website and access the full study yourself . it was published in the jan 1, 2004 issue. And yes the study involved discordant couples who were making the effort to protect their partner and were aware of their hsv2+ status.

The risk per sex act is pretty  darn low even in someone who isn't aware of their status.

grace

[waringblender]

Read this and maybe it will help you. At least it might help you with the issue of perspective on transmission:

http://www.medhelp.org/posts/show/394516

[Dobot]

One more question:

Does anyone know then what the statistic is for an uninfected person who has unprotected sex with HSV-2 positive person? The study that includes HSV-2 positive people who know they have it and HSV-2 positive people who don't know they have it.

Thanks

[Dobot]

hmmm,

ok. Maybe that makes sense.

You guys are saying that the 3-5% statistic was a study done with people that knew they had herpes and only had sex when they didn't show any symptoms. And this study concluded that an uninfected person has a 3-5% chance of contracting HSV-2 while having unprotected sex with a person that has HSV-2, though not showing any symptoms during the time of intercourse.

Do you have a link or something I could read showing these details? I've only been able to find vague statistics and hate making assumptions. Though these ideas and thoughts are greatly appreciated I just want to make sure I get my details straight.

Thanks guys.

[gracefromHHP]

As waring said - the stats we use here are in folks who are aware that they are infected with hsv2 genitally.  No idea you are infected then you are more likely to have sex when you have symptoms which having sex when the virus is active is a greater risk of transmitting the virus.  For instance say waring or I had an itch around our anal area that lasted all day long. We know we have herpes so we are more likely to say to our dates that tonight - you know I better not have sex tonight because I"m not sure if i"m having an ob or not.  Someone who didn't know they had herpes would be more likely to say - geez my *** has been itchy today while they are having sex with someone ( ok so you'd be in a relationship awhile before you'd talk like that during sex....lol ).  Waring and I would be protecting a partners while the other person would be putting their partner at risk if indeed that butt itch was herpes.  Does that make it easier to understand why 25% of folks on average are infected with hsv2 even though the yearly rates of transmission are pretty low overall?

Also some folks aren't educated enough about their herpes.  They think that if they wear a condom that they are protecting their partner even if they have active symptoms.  If you are in a discordant relationship ( where one partner is infected and the other isn't ) you shouldn't have sex during ob's since you are shedding the virus from the location of the lesion and from the entire anogenital area.

grace

[waringblender]

You seem to be confusing two sets of data: the studies that say 25% of the population has it; and the studies that say you have a 5% chance of getting it over the course of a year from a person who has it.

That 5% rate of contraction stands on its own. It has nothing to do with how many people have herpes, or how many know they have herpes. It stands on its own, meaning that if you have sex with somebody who has herpes, that is your rate of risk if you had sex with them over the course of a year.

[waringblender]

Right. As far as I know (and someone can correct me here), the statistics on contracting it (the percentages) come from studies with subjects who already knew they had herpes.

How can the statistic go from 5% to 25%? That makes no sense. Let's say you have sex with somebody whose herpes status you don't know. They have about a 20-25% chance of having herpes. Already you're beating the odds, because they have a 75-80% chance of NOT having it. But if they happened to have herpes, the odds you would contract herpes from them is still 3-5% over the course of a year. That's not even each episode of sex. That's over the course of a year. How could that number jump, then, from 5% to 25%? If anything, that number would be lower than 5% because you don't even know their status to begin with.

Even if you have sex with a person with herpes who doesn't know they have it, your chance of contracting it with each episode of sex is low. I mean, hell, if it's 5% over the course of a year (without protection), think how low each episode of sex is percentage-wise.

Maybe I'm not explaining it well. I'm not a numbers person, and I have people at work who crunch numbers like this for me so I don't have to do it. :)

What is it you are trying to understand, though? Can you just accept that these are the numbers that the studies have come up with? What about them doesn't make sense?

[Dobot]

so you're saying that the 3-5% chance of contracting HSV-2 with out a condom is not taking into consideration the HSV-2 positive population that unknowingly has it?

So does this mean that the odds of getting HSV-2 with out a condom is really closer to the 25% number (taking into consideration unknowing sex partners)?

[waringblender]

I'm not sure what the doctors on the STD expert forum are charging, but it sure as sh*t is not what you would pay for an office visit, and they are experts in STDs. I think it might be 20$ or so. Does that seem like a lot for a professional opinion from guys at the top of their game in their field of expertise? I'm a professional myself and wouldn't dream of charging that little, so whatever opinion you get from the doctors is a bargain, believe me.

The reason the statistics are 1 out of 4 people with genital herpes is because most of the people (like upwards of 90%) don't even know they have it. If they don't know they have it, they can't protect their partners from contracting it.  They either have no symptoms, or they have symptoms that they don't recognize as herpes, like paper-cut like things, or they think it's an ingrown hair, or jock itch, or they cut themselves shaving, or whatever.

I'm not a statistician, but none of those statistics seem correlative to me. In other words, just because there's only a 3-5% chance with a condom, or whatever it is, doesn't negate that 25% of the population has it. See what I mean? At least, that's how I interpret those numbers.  

It's easier not to contract it than it is to contract it, even without protection. Just knowing you have it goes a long way towards protecting your partners. You can start adding preventive measures towards that, like condoms, or the medication, and you are only improving your odds of not getting it.

BTW, the Valtrex works better than 50%. That's probably the minimum amount of prevention you'd get with it.