Sexually transmitted co-infections increase HIV risk: study

Bacterial and viral sexually transmitted infections can exacerbate HIV replication in co-
infected individuals, a team of Canadian researchers led by Charu Kaushic, associate
professor of pathology and molecular medicine, has found.

“While sexually transmitted infections are associated with increased HIV-1
susceptibility
and viral shedding in the genital tract, the mechanisms underlying this association are
poorly understood,” said Kaushic about the study that appears online this month in the
Journal of Infectious Diseases. “Our research has found that normal response to these
infections by the epithelial cells (the cells that line the genital tract) can lead to
increased HIV replication in the female reproductive tract.”

Through this study, Victor Ferreira, a graduate student in Kaushic's lab revealed
how
bacterial (gonorrhoea) and viral (genital herpes) sexually transmitted infections can
increase HIV replication in co-infected individuals, opening new doors of
understanding.

“Clinical studies have clearly shown that co-infection with herpes and gonorrhoea
makes HIV infection worse and large trials have been conducted to study if controlling
these infections can make HIV infection less invasive and less transmissible,” says
Kaushic, a member of McMaster's Institute for Infectious Disease Research. “The benefit
of treating co-infections has not been as impressive as was expected, and this study
increases our understanding of why that might be. We discovered that inflammation
plays a key role in HIV replication. It's not necessary that if you control those infections,
the inflammation is gone. So it might be useful, that in addition to treating these co-
infections with antibiotics or antivirals, to control the inflammation and this might be
more effective in stopping HIV replication rather than controlling just the infection.”

The study was supported by an Emerging Team Grant on Co-infections from the
Canadian Institutes for Health Research and a scholarship to Victor Ferreira from
Ontario HIV Treatment Network.