Gonorrhoea is STI most likely to cause HIV rebound in semen of HAART patients

The majority of gay men with an undetectable viral load in their blood, still had an undetectable viral load in their semen, even when they had an untreated urethral infection, according to research presented to the UK's Public Health Laboratory Service scientific conference on September 10th.

The findings were published earlier this year in the journal AIDS.

All the men with undetectable virus in their blood but detectable HIV in their semen were infected with gonorrhoea, suggesting to Dr Steven Taylor of Birmingham University that gonorrhoea was “particularly inflammatory.”

He was reporting on a study carried out amongst HIV-positive sexual health clinic attenders in London and Birmingham designed to see if having an active sexually transmitted infection increased seminal viral load.

Twenty-four HIV-positive men with sexually transmitted urethral infections (gonorrhoea, chlamydia or NSU) were recruited to the study as were a control population of sixteen HIV-positive men who attended for sexual health check-ups but were found to be free of infections. Both the study and control populations had received at least three months of HAART and had similar baseline characteristics.

Of the sixteen men in the control arm, nine were found to have undetectable levels of HIV in both their blood and semen. Similarly, amongst the 24 men found to have a urethral STI, 18 had undetectable viral loads in both their blood and semen. One person had an undetectable viral load in his blood but a detectable seminal viral load and four had HIV detectable in both blood and semen. Four of the men with STIs and HIV detectable in their semen were infected with multi-drug resistant strains of HIV.

However, when treated with antibiotics, seminal viral loads became undetectable in three of the men, and in a fifth man’s seminal viral load fell from over 100,000 copies/mL to 4,300 copies/mL, a drop of over 1.5 log in two weeks.