Confused about the swiss study

Question

I discussed with my doctor about the swiss study which claims that in a monogamous serodiscordant and straight relationship with the infected partner on treatment and with an undetectable viral load the use of a condom is no more imperative. He agrees. I asked him about the possibilities of blips and differences between plasma and seminal fluids concerning viral load and he said that those changes and variations are likely not indicative for a significant trasmission risk since the copies detected are dead virus particles flowing around without the capability to infect a cell. He also said that those few cases which reported transmission with an undetectable viral load were related to poor and suboptimal adherence. What is the truth? Is unprotected sex with a single partner and under the rules of the swiss statement so extenuating low that condoms could be avoided at least for natural conception?

Answer

Thanks for your question.

The recommendations were based on the finding that lowering the viral load will indeed lessen the risk of transmission of HIv but may not eliminate it. Studies that examined men on HAART with undetectable viral loads in their blood (plasma) demonstrate that 3 to 5% of men wioll have HIv in their semen at some point. So, on an individual basis, their is some risk for transmission. Virus can be shed intermittently, so it could occur sporadically despite undetectable viral load in teh blood. Your doctor is correct that this virus is not a risk to you because the HAART will prevent it from infecting other cells. The virus that is shed does not have to reproduce itself, it is generated from the cells that are left infected with HIV viral genes from before the meds shut the virus down. However, it is capable of growing in an unprotected person (that is it is replication competent).

So, the risk of transmitting HIV is much much lower if HIV is undetectable in the blood, but may not be zero, and may change from day to day.

Hope this helps, Joe