Is there a cumulative risk of transmission? "1% chance of transmission per year"

Hi friends,

We have this statistic that says that an H+ female has a 1% chance of passing the virus per year, if she uses both protection and medication.

The statistic for guys is 2.5% chance per year, using (as well) both condoms and medication.

I have several questions from here:

1) How many sexual acts per week are considered for this stat? Is it safe to establish that 2 sexual acts per week is the average to consider this statistic?

2) Is this 1% (or 2.5%) "decided" after that amount of sexual acts? I mean, after 104 intercourses (52 weeks, sex 2x per week), you "roll the dice" and you have 1% of possibilities to catch it...?

3) ...Or is it a fixed chance ("if you have 100 intercourses, 1 of them WILL infect your couple absolutely")?

4) If it is a probability (and not a security) after those many sexual acts, what if I reduce the frequency to 1 sexual act per week instead of 2 - would that reduce in half the risk?

5) Finally, is this risk cumulative? Or every year the counter goes "back to zero"?

Many thanks,

I mean, is VERY DIFFERENT if:

a) you have 1% of PROBABILITIES of passing it after a year of regular sex (in that case, you would need a century, or 100 years of regular sex -LOL-, to "make sure" a transmission was made with medication + condoms)

...or...

b) you risk that for every 100 sexual acts, 1 of them passes the infection. In that later case, it would be much more dangerous, right?

Something tells me is option "a", but wanted to make sure.

That was my doubt essentially.

But also wanted to ask about the cumulative part. Does the risk doubles in year #2?

*Disclaimer, studies vary by percentages somewhat but generally this is how it works.

Au Naturate

Male to Female - 10% Transmission Rate

Female to Male - 4% Annual Transmission Rate

Use of Anti-viral or Condom

Male to Female - 5% Transmission Rate

Female to Male - 2% Annual Transmission Rate

Use of Anti-viral and Condom

Male to Female - 2.5% Transmission Rate

Female to Male - 1% Annual Transmission Rate

With the studies I've read, the assumption that 2 sex acts per week is average. So a little more then 100 occurrences annually. The percentages also assume sex is avoided when signs of an OB begin.

Statistically speaking, this means that if a male was to have sex with 100 people over a year and all forms of precautions are taken, it would be expected that HSV would be passed on the 2 or 3 people. This would be 10,000 sex acts! So the risk is pretty low, but it's still there and that's why disclosing is still necessary IMO and in some cases it's the law.

As far as the risk in subsequent years, it does not change. Year 1 and year 2 are mutually exclusive of each other. This is just statistics. For example, if you flip a coin and heads came up 4 times in a row, the probability of it being heads on the 5th flip is still 50%.

Hope this helps!

You're right, the statistics assume quite a lot and generalize pretty blatantly.

The real situation is that the statistics won't predict the future.

That's why disclosure and consent are absolutely vital to both the diagnosed person and the H- person.

Basically, if an H- person comes into contact with the virus, they will contract it. The statistics only serve to prove the effectiveness of disclosure, taking suppression medicine and using condoms in reducing risk (not eliminating risk at any point for any person. There is always risk).

So I'm not a math guru or anything but I have asked myself this question a lot and was not really convinced with the replies I had read that the risk remains at 2-3% considering rates for genital hsv1 transmission which what I was thinking about.. Anyway, I took 3% as a safer margin and here is what I found by probability calculation ; it's called Bernoulli Process:

Let's say y is the risk of transmission per year and it is 3% or 0.03. T is the transmission risk over 30 years.

So we're 97% safe each year or 0.97.

Let's see how long can we still be safe for 30 years?

That will be 0.97 to the power of 30 which is about 0.401 or 40 %.

So over 30 years of marriage with regular sexual activity and despite the low incidence per year there's a 60 % chance that your partner will catch the infection. Depressing but this is math:

T=1-(1-y)^30

T=1-(1-0.03)^30

T=1-(0.97)^30

T=1-0.40

T=0.60 or 60%

Pretty significant unfortunately. I wish it was much less.

Hope all is well.

For your question regarding the 1% risk and again I'm calculating over 30 years the risk of transmission is 26 % because 0.99 to the power 30 is roughly 0.74 or 74% of staying safe for that long.

Much lower so maximizing protection to get as close to the 1 % risk as possible goes a long way even mathematically speaking.

Hi @benzgt excellent input, thanks.

74% of staying safe in a lifetime of sex is better than nothing... but it still leaves a wide room for something bad to happen. I don't know how to feel about it.

I calculated male-to-female risk using condoms + medication, and it gives 0.467, or about 47% of staying safe after 30 solid years of sexual activity 2x per week.

That is, 53% of possibilities you would pass it. Half of that, I assume, if you go 1x per week.

It is somehow depressing.

I'm looking into some condoms for men that cover the penis base, will post soon about it.

@happyman_adventurous You're welcome.. Please keep us posted.

I wonder why there is not so many talking about that risk mathematically? I know these are just estimates and would not predict the future but still calls for a plan to mitigate the situation the best we can.

Anyway, thanks for making me think more analytically about it and take care

On ‎2018‎/‎05‎/‎28 at 11:52 PM, happyman_adventurous said:

Hi @benzgt excellent input, thanks.

 

74% of staying safe in a lifetime of sex is better than nothing... but it still leaves a wide room for something bad to happen. I don't know how to feel about it.

 

I calculated male-to-female risk using condoms + medication, and it gives 0.467, or about 47% of staying safe after 30 solid years of sexual activity 2x per week.

 

That is, 53% of possibilities you would pass it. Half of that, I assume, if you go 1x per week.

 

It is somehow depressing.

 

I'm looking into some condoms for men that cover the penis base, will post soon about it.

Well if your still with her after 30 years does it still matter of you catch it?

Well its just draw of the luck I will say. I never got lucky in winning a lottery but got lucky in getting herp by one unprotected encounter 🤷‍♂️