[renotime]

(09-25-2018 02:29 PM)spydersuit Wrote:  

(09-24-2018 08:54 PM)renotime Wrote:  

According to CDC:

Three recent studies, PARTNER, Opposites Attract, and PARTNER2 (an extension of PARTNER focusing on HIV-discordant MSM couples), report similar results. None of these studies observed any genetically linked infections while the HIV-positive partner was virally suppressed and the couples were engaging in condomless sex and not using pre-exposure prophylaxis (PrEP).8,9,10 In these studies, viral suppression was defined as less than 200 copies of HIV RNA per milliliter of blood; most HIV-positive participants in the PARTNER study had less than 50 copies of HIV RNA per milliliter of blood.8 The three studies included over 500 HIV-discordant heterosexual couples, with about half having a male HIV-infected partner (PARTNER), and more than 1,100 HIV- discordant MSM couples (PARTNER2; Opposites Attract) from 14 European countries, Australia, Brazil,
and Thailand.
The studies reported transmission risk estimates and their corresponding 95% confidence intervals as:
• PARTNER study:8
- For any sex among heterosexual and male-male couples: 0.00 (0.00 – 0.30) per 100 couple-years - For anal sex among male-male couples: 0.00 (0.00 – 0.89) per 100 couple-years
• Opposites Attract study:9
- For anal sex among male-male couples: 0.00 (0.00 – 1.59) per 100 couple-years
• PARTNER2 study (which includes data from PARTNER):10
- For anal sex among male-male couples: 0.00 (0.00 – 0.24) per 100 couple-years

Together, the data from the PARTNER2 and Opposites Attract studies produce a combined transmission risk estimate for condomless and PrEP-less anal sex among MSM couples of 0.00 (0.00 – 0.21) per 100 couple-
years, with the upper bound equal to a 0.21% annual risk (unpublished data). Pooling data from all three studies produces a combined transmission risk estimate for condomless sex among heterosexual or MSM couples of 0.00 (0.00 – 0.14) per 100 couple-years, with the upper bound indicating a 0.14% annual risk (unpublished data). These data provide solid evidence of the power of viral suppression in preventing HIV transmission. Statistically, the possibility exists that the true risk is greater than zero; however, data show no linked infections while the HIV- infected partner is virally suppressed, based on tens of thousands of sex acts without a condom or PrEP. Based on these data, future HIV transmission is not expected when persons with HIV remain virally suppressed.

https://www.cdc.gov/hiv/pdf/risk/art/cdc...ession.pdf

It sounds like chances of transmission are nil as long as you're on the proper meds.

1. that is not 0.
2. And a confidence interval - you are either in it, or you are not. 5% are not in it.
3. the 95% confidence interval, while still a commonly used statistic, is out of date and a very low threshold for medical evidence.
4. in real life, what are the odds of someone forgetting to take their meds? extremely high. Patient compliance is crap.
5. the data reported are valid, the problem is that in real life things are messier
6. PReP is highly effective when taken correctly FWIW: I know high risk sex participants that take PReP and have not contracted the HiV.
7. You guys should take PReP if you are banging lots of women (who knows how risky some of these women are)

"‘Zero’ needs a precise explanation. When principal researcher Alison Rodger announced the results of the first phase of the study, PARTNER 1, back in 2014, she said, of the risk of transmission by an undetectable partner, that “Our best estimate is, it’s zero”.

By ‘estimate’ she meant that it is impossible to prove that something will never happen. So researchers use confidence intervals. These do not state what the findings show, but what they can show. They define how precise their findings are.

In the first announcement of the PARTNER 1 data, concerns were expressed because what is called the ‘higher bound of the 95% confidence interval’ was 0.45% for all, but 0.84% for any sex between gay men and 4% for receptive anal sex with ejaculation.

The 0.45% means that, if you were to run PARTNER 1 20 times, it would become more likely than not that, one time out of these 20 study repeats, you’d find one HIV transmission in every 222 couples if you followed them for a year – or one transmission in any one couple if you followed them for 222 years. The 4% would increase that likelihood to one in 25 couples per year (or one transmission every 25 years per couple).

It is important to stress that these might not be real events. The confidence interval is a statement about ‘noise’, and so is a statement both about the chances of missing one transmission (a false-negative) and about the chances of mistakenly ‘seeing’ a transmission that isn’t real (a false-positive).

The fact that the higher bound for anal sex was higher than for all sex was not due to the fact that anal sex transmits HIV more efficiently than vaginal. It was because there were fewer couples who had anal sex – so the resolution of the findings was lower, like a photo with fewer pixels.

It especially did not mean, as some people misunderstood, that the likelihood of transmission from an undetectable condomless anal sex partner where the positive partner was insertive and ejaculated was 4%. It was still the case that the most likely chance of transmission was zero.

But because there were fewer gay than heterosexual couples in PARTNER 1, it was decided to recruit more couples, to narrow the confidence intervals for anal sex between men. These new couples, plus the original gay couples from PARTNER 1, formed the cohort studied for PARTNER 2."

http://www.aidsmap.com/Zero-transmission...e/3311249/

Still sounds like zero to me as long as you are virally suppressed, but it's possible I might be missing something.