Undetectable HIV Viral Load in the Blood? Not Necessarily in Semen, Boston HIV Study Finds

Undetectable HIV Viral Load in the Blood? Not Necessarily in Semen, Boston HIV Study Finds

Can someone with no detectable HIV virus in their blood due to successful HIV treatment infect someone?

“Undetectable viral loads in blood is not a guarantee that HIV is also undetectable in semen, according to a new study involving 101 HIV-positive men who have sex with men (MSM) conducted in Boston and published online ahead of print by the journal AIDS. Of the 83 men with undetectable virus in blood samples, roughly a quarter of them—21 MSM in total—had semen with detectable HIV.”


“Eighty-three of the 101 MSM (men that have sex with men) had undetectable levels of HIV in their blood samples. Though most also had undetectable HIV in their semen samples, 21 (25 percent) had detectable seminal viral loads”
How long had these 21 MSM guys been on HIV meds? What was the rate of other active sexually transmitted infections in this sub group?

“..the average free-floating viral load was 4,438 copies among those with detectable blood-based HIV levels, it was 51 copies among those with undetectable blood-based HIV levels. “
Are these 51 viruses enough to infect someone?
Previous studies that looked at this found a rate of around 8 percent. And some researchers say that these viral particles may consist mostly of pro-virus and not active “infectious” virus.

I wish they had measured blood and intra-cellular levels of anti-retrovirals to see if they correlate with semen’s HIV viral load.

Read this great article by Tim Horn:

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