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Clinical Test is unethical?

Nov 19, 2009

Dr Bob,

First I would like to say that I love your column and find you very informative.

In one response you wrote "Unprotected vaginal sex with a guy known to be HIV positive does indeed carry a significant risk for HIV transmission, even if the guy's viral load is undetectable. It is true that having an undetectable viral load decreases the risk of HIV transmission somewhat, but certainly not completely. Also, the HIV viral load measured in the blood may be different than the HIV viral load in the ejaculate. I can't give you exact percentages on risk, as actually conducting a clinical trial to determine this would be unethical. Suffice it to say that the risk is definite and consequently should definitely be avoided. Please show this post to your husband. "

Can you answer why you think that a clinical trial to determine the hiv load in semen would be unethical?

Men are constantly donating semen for sperm donations, etc.


Rick NH

Response from Dr. Frascino

Hey Rick,

I think you may have misunderstood my comments. Studies have already been done comparing simultaneous HIV viral load in the plasma (blood) compared to semen. That's why I mentioned that "the HIV viral load measured in the blood may be different than the HIV viral load in the ejaculate."

The "unethical" hypothetical clinical trial I referenced would involve prospectively monitoring unsafe sex in a group of magnetic couples when the HIV plasma viral load is undetectable and comparing them to a matched group of similar magnetic couples having protected sex to ascertain exactly how many of the partners in the unsafe group become HIV infected! We know HIV transmission can and sometimes does occur in this setting. Consequently, we could never sanction such a trial, ethically speaking, knowing that some of the trial participants would become HIV infected.

Dr. Bob

worried sick about HIV risk and symptoms
Case numbers for rare subtypes (TESTING FOR SUB-TYPE O)

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