Undetectables----Quick Question

[racingmind]

A fellow poz friend told me that his doctor (at the University of Pennsylvania) said that when you are undetectable the risk of transmission is next to nothing.  Of course, there is a risk if you don't use a condom for intercourse, but you are so much less infectious for other activities.  Just wondering, has anyone else heard this information from their ID doctors?  I'd like to think that it's true, but I don't want to take "hearsay" as fact either.  I plan on asking my ID doctor on my next visit, but in the meantime, I was wondering what information this group might have heard....

ps. happy holidays

[Tim Horn]

Hi racing:

Yes, there's a great deal of merit to this line of thinking.

It all started back in 2000, when researchers published results from a study that enrolled 415 HIV-negative people living in the rural Ugandan Rakai district. During a 30-month follow-up period, 90 (22%) of the study volunteers were infected with HIV. To better understand the circumstances surrounding these infections, the researchers also questioned and tested the study subjects' HIV-positive sex partners. It turned out that anyone who had an HIV-positive sex partner with a viral load below 10,000 remained HIV-negative, whereas all of those who ended up positive had sex partners with viral loads higher than this level. This led to the conclusion that, the lower the HIV-positive person's viral load, the less likely he or she is to transmit the virus to others.

There has been a slew of additional studies conducted since 2000, basically showing that a person's viral load in blood correlates nicely with his or her viral load in the genital tract -- the lower it is in the former, the lower it is in the latter (read: they're less infectious). Unfortunately, research has demonstrated enough discordance to conclude that the risk isn't reduced to zero. There have been studies showing that people with undetectable blood viral loads still have detectable seminal viral loads (and vice versa). Even more troubling are results from studies showing that someone can have an undetectable blood viral load and detectable drug-resistant virus in his semen (and vice versa). Plus, undetectable -- using today's technology -- is often interpreted to mean "extremely low"... sadly, it doesn't mean "non-existent."

What this boils down to is that the risk of transmission is greatly reduced if the positive partner has a very low viral load (most likely with the help of antiretrovirals) -- "next to nothing," I suppose, is a good way of saying this. So much so that an "undetectable viral load" is now considered to be an established factor in prevention education.

Tim Horn

[Ann]

There has been a slew of additional studies conducted since 2000, basically showing that a person's viral load in blood correlates nicely with his or her viral load in the genital tract -- the lower it is in the former, the lower it is in the latter (read: they're less infectious). Unfortunately, research has demonstrated enough discordance to conclude that the risk isn't reduced to zero. There have been studies showing that people with undetectable blood viral loads still have detectable seminal viral loads (and vice versa). Even more troubling are results from studies showing that someone can have an undetectable blood viral load and detectable drug-resistant virus in his semen (and vice versa). Plus, undetectable -- using today's technology -- is often interpreted to mean "extremely low"... sadly, it doesn't mean "non-existent."

At the risk of being pedantic, I think it's worth repeating the above portion of Tim's post. Being undetectable is not a license to bareback. Negotiated risk in the context of a relationship is one thing, but flagrantly throwing condoms out the window is something else entirely.

Please remember to continue using condoms with negative partners unless you've discussed the fact that there is still a risk (albeit reduced) of transmission - and they're comfortable with it.

Ann

[newt]

Tim, I would like to see the study yo talk about which showed 0 transmission at viral load under 10,000.

The "classic" Rakai studies eg:

Male-to-female and female-to-male HIV transmission rates in discordant couples, Rakai, Uganda.

showed no M-to-F transmission occurred at viral load under 1,572 copies/mL and no F-to-M transmission occurred at viral load under 1,801, and:

Probability of HIV-1 transmission per coital act in monogamous, heterosexual, HIV-1-discordant couples in Rakai, Uganda

which showed that transmission probability increased from 1 in 1000 "per coital act" at viral loads of less than 1,700 to 23 in 1,000 at 38 500 copies.  So I don't see that the risk at a viral load of 10,000 is gonna be "next to nothing", unless you can show me the paper, and even then, given the other findings in the literature, it will be debatable.

But I agree -- undetectable viral load prob means the risk of transmission is "next to nothing" for south Ugandan heterosexual couples.

- matt

[Tim Horn]

Hi Matt --

Yes, you're right. Here's a link to a review of the original NEJM article. While the average viral load among the HIV-positive participants who didn't infect their partners was below 4.0 log copies/mL, the authors expressly state that no infections occurred when the positive partner had a viral load below 1,500, not 10,000.

But I'm not going to get into regression analysis as a well documented manner of determining risk. These 1-in-1000 projections are totally arbitrary and do a lot of injustice to real-world concepts of "negotiated risk." And you know, just as well as I do, that this doesn't only refer to south Ugandan heterosexual couples. I include these data here to show that there's a "dose-response" relationship between viral load and transmission, period.

Tim Horn

[esquimau]

and just a couple additional variables that may or may not play into the risk.

Seminal/vaginal viral load may not be the same as your bloods VL, may not drain out at the same rate, not sure.

I remember reading a study (and if I can find the abstract will link it) that was tracking serodiscordant couples that seemed to think that when repeatedly exposed but not infected to a partner's virus, the negative partner seemed to develop a slight protection to that virus that wasn't there when it was challenged by someone that wasn't their main partner.  I am not aware of any follow up studies that came out of that and now that I think about it, I'm curious if they did any.  But that might indicate that there would be a different threshold of risk for those in monogamous relationships vs those that aren't.

Real world analogy would be cat allergies.  You can get desensitized to your own cat's dander and still be very allergic to your friend's cat.

[racingmind]

Thanks for the replies,

Just to let you know, I would NEVER consider having an undetectable viral load a licence to bareback.  I just was curious as to what ID docs are saying to their patients out there....

RM

[poz1970]

My own personal take on this is that the risk is 'minimised', there still is a risk (as there is with 'safer' sex)...

Whatever your viral load, and whether its been measured in your semen, blood etc might have an impact on any statistical outcome...

Each to their own, we make our own beds etc, but I think at this stage, if I infected anyone, I'd probably off myself...  Its not a risk I want to take with people that I love and care for.


J

[Winiroo]

Sounds like an irresponsible thing for a doctor to say. My guess would be that typically docs dont suggest <even if it may be true> that when you are undetectable the risk of transmission is next to nothing.

A risk is a risk is a risk

Kinda like those guys on Maury that claim "that baby cant be mine, I only had sex with her once."

Not bright...




<Modified cause I mispelled something>

[Jacques]

Well, it seems that other experts and searchers are following this line of thinking, in particular Pr Bernard Hirschel, a well known swiss searcher.

A French-Swiss HIV expert generated much interest and debate last week among European activists on preventing and controlling AIDS after he spoke to the media explaining his theory that triple combination therapy could potentially be the answer to many vexing HIV questions, including what to do to stop AIDS since a vaccine is not an option.
Olivier Jablonsky, of the Paris-based radical activist health organization WARNING, tipped me off to a few of the stories and interviews with Dr. Bernard Hirschel, a leading researcher in global HIV/AIDS concerns.
His basic view, as I understand it, is that AIDS cocktails knock down the HIV viral load to undetectable or extremely low levels, making positive persons non-contagious. However, he also acknowledges there is still no zero risk of spreading new HIV infections, something to always keep in mind.
It seems Hirschel is proposing that if HIV positive people properly adhere to taking their AIDS medicines, reducing their viral loads to undetectable, and their ability to transmit the virus, the positive person won't pass on HIV even if that person doesn't practice safe sex.
And if HIV positive people are not further transmitting the virus, better control of the epidemic can be achieved.
If this is the case, then it means radical change will be necessary in designing effective prevention social marketing campaigns and the work of public health authorities everywhere.
Hirschel's provocative theories should foster lots of discussion among prevention organizations and activists. Indeed, there will be a public chat with Hirschel, sponsored by the Swiss gay group DialoGai, in Geneva on January 24, 2008.
Here are excerpts from Swiss news reports, roughly translated using Google. In the coming week, I trust and expect Dr. Hirschel's new ideas and supporting data will be better translated into English and circulated more widely. Let's debate his theories and their implications for fighting AIDS.

The Tribune de Geneve's story, gets the ball rolling:

Professor Hirschel says that if the virus became undetectable, the infected person is no longer contaminating.

This is good news, but it is cumbersome. In most patients infected with HIV, the triple therapy reduced the rate of HIV in the blood to become undetectable. Does it mean that these people are no longer contagious, even if they engage in unprotected sex? "Yes," replied Dr. Bernard Hirschel, unity HIV / AIDS to the University Hospital of Geneva. "No detectable virus, no infection." [...]
The specialist HIV / AIDS has sought further evidence of this safety. Empiriques essentially. "We tried to find, with our colleagues in other hospitals Swiss exceptions to the rule. Despite thousands of new infections since 1996, we have identified a single case possible Geneva, dating from 1997 transmission from a patient following a triple apparently effective. But we were unable to verify that its viremia was undetectable. "

Moreover, following the abandonment of condoms in certain populations, the number of sexually transmitted diseases (syphilis, chlamydias ...) has increased. But not the incidence of HIV, as shown by a study conducted among homosexuals in San Francisco. "The only plausible explanation for this paradox is once again the triple," says the Professor. "By reducing viral load, it helps prevent the spread of HIV. " [...]

link to full text:

http://mpetrelis.blogspot.com/2007/12/swiss-expert-aids-cocktail-prevention.html


Jacques